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Do standing orders help with chronic disease care and health maintenance in ambulatory practice?
RESULTS ARE MIXED. Studies of standing orders tend to examine their effect on compliance with preventive interventions for chronic disease rather than disease outcomes. In the ambulatory setting, they improve rates of influenza vaccination (strength of recommendation [SOR]: C, consistent cohort studies measuring vaccination rates), pneumococcal vaccination (SOR: C, consistent randomized controlled trials [RCTs] measuring vaccination rates), childhood immunizations (SOR: C, inconsistent RCTs measuring vaccination rates), and mammograms (SOR: C, RCT measuring screening rate).
Standing orders don’t improve screening rates for colorectal cancer (SOR: C, RCT measuring screening rate).
Evidence summary
Organizational changes in physician offices can improve delivery of services for preventing and controlling disease.1 Standing orders—typically defined as physician-approved protocols that authorize nurses or other staff members to perform procedures, such as immunizations without direct physician involvement1—are readily applicable in ambulatory settings. However, only 30% of physicians use standing orders in their practices.2
Research on standing orders in ambulatory care has focused on immunizations and cancer screening (TABLE). Interventions implementing standing orders typically have multiple components and include staff education, chart flow sheets, and recall-reminders for patients.
TABLE
Effect of standing orders in ambulatory practice
| Disease | Standing order | Improvement in vaccination or screening rate | NNT* |
|---|---|---|---|
| Pneumococcal disease3-5 | Pneumococcal vaccine | Baseline range: 5%-15%; Follow-up range: 25%-28.3% | 3.7-10 |
| Influenza6-8 | Influenza vaccine | Baseline range: 32%-51.4%; Follow-up range: 58%-74.6% | 3.8-4.3 |
| Cancer screening3 | Mammogram | Baseline: 33%; Follow-up: 60% | 3.7 |
| Childhood illnesses9 | Immunizations, ages 2-5 yr | Baseline: 14%; Follow-up: 29% | 6.7 |
| *Number needed to treat (NNT) is based on the number of additional patients who receive an intervention based on the number who may be exposed to the standing order. | |||
Improvement in pneumococcal and flu vaccine rates
Three multicomponent RCTs of outpatient standing orders reported improved pneumococcal vaccination rates.3-5 Similarly, 2 prospective, multicomponent cohort studies6,7 and 1 retrospective study8 found improved rates of influenza vaccination with standing orders.
Childhood vaccination rates also show positive trends
Two controlled trials (1 randomized3 and 1 nonrandomized9) that incorporated standing orders examined their use in childhood immunizations (measles, mumps, and rubella [MMR]; oral polio vaccine [OPV]; Haemophilus influenzae, type b [HIB]; diphtheria and tetanus toxoids with acellular pertussis [DTaP]; and hepatitis B). One trial reported increased use of acute care immunization opportunities;9 the other showed a nonsignificant positive trend in vaccination rates.3
Standing orders increase 1 form of cancer screening, not another
A multicomponent RCT of standing orders for mammography and colorectal cancer screening found a statistically significant increase in screening for mammography, but not colorectal cancer.3
Recommendations
The Society of Adolescent Medicine recommends standing orders for administration of influenza vaccine during flu season.10
The Task Force on Community Preventive Services recommends standing orders for adult vaccinations based on “strong evidence,” but states that insufficient evidence exists to recommend standing orders for childhood vaccinations.11 Vaccines examined include MMR, DTaP, HIB, hepatitis B, and varicella for young children; hepatitis B, varicella, MMR, and tetanus-diphtheria toxoids (Td) for adolescents; Td for adults up to 65 years of age; and influenza and pneumococcal vaccines for adults 65 years and older.
The Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention recommends standing orders for influenza and pneumococcal vaccines.12
1. Stone EG, Morton SC, Hulscher ME, et al. Interventions that increase use of adult immunization and cancer screening services: a meta-analysis. Ann Intern Med. 2002;136:641-651.
2. Nichol KL, Zimmerman R. Generalist and subspecialist physicians’ knowledge, attitudes, and practices regarding influenza and pneumococcal vaccinations for elderly and other high-risk patients: a nationwide survey. Arch Intern Med. 2001;161:2702-2708.
3. Mold JW, Aspy CA, Nagykaldi Z. Implementation of evidence-based preventive services delivery processes in primary care: an Oklahoma Physicians Resource/Research Network (OKPRN) study. J Am Board Fam Med. 2008;21:334-344.
4. Rhew DC, Glassman PA, Goetz MB. Improving pneumococcal vaccine rates. Nurse protocols versus clinical reminders. J Gen Intern Med. 1999;14:351-356.
5. Herman CJ, Speroff T, Cebul RD. Improving compliance with immunization in the older adult: results of a randomized cohort study. J Am Geriatr Soc. 1994;42:1154-1159.
6. Margolis KL, Nichol KL, Wuorenma J, et al. Exporting a successful influenza vaccination program from a teaching hospital to a community outpatient setting. J Am Geriatr Soc. 1992;40:1021-1023.
7. Nichol KL, Korn JE, Margolis KL, et al. Achieving the national health objective for influenza immunization: success of an institution-wide vaccination program. Am J Med. 1990;89:156-160.
8. Goebel LJ, Neitch SM, Mufson MA. Standing orders in an ambulatory setting increases influenza vaccine usage in older people. J Am Geriatr Soc. 2005;53:1008-1010.
9. Christy C, McConnochie KM, Zernik N, et al. Impact of an algorithm-guided nurse intervention on the use of immunization opportunities. Arch Pediatr Adolesc Med. 1997;151:384-391.
10. Kharbanda EO, Maehr J, Middleman AB, et al. Influenza vaccine: a position statement of The Society for Adolescent Medicine. J Adolesc Health. 2007;41:216-217.
11. Vaccine-preventable diseases: improving vaccination coverage in children adolescents and adults. A report on recommendations from the Task Force on Community Preventive Services. MMWR Recomm Rep. 1999;48(RR-8):1-15.
12. Harper SA, Fukuda K, Uyeki TM, et al. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2004;53 (RR-6):1-40.
RESULTS ARE MIXED. Studies of standing orders tend to examine their effect on compliance with preventive interventions for chronic disease rather than disease outcomes. In the ambulatory setting, they improve rates of influenza vaccination (strength of recommendation [SOR]: C, consistent cohort studies measuring vaccination rates), pneumococcal vaccination (SOR: C, consistent randomized controlled trials [RCTs] measuring vaccination rates), childhood immunizations (SOR: C, inconsistent RCTs measuring vaccination rates), and mammograms (SOR: C, RCT measuring screening rate).
Standing orders don’t improve screening rates for colorectal cancer (SOR: C, RCT measuring screening rate).
Evidence summary
Organizational changes in physician offices can improve delivery of services for preventing and controlling disease.1 Standing orders—typically defined as physician-approved protocols that authorize nurses or other staff members to perform procedures, such as immunizations without direct physician involvement1—are readily applicable in ambulatory settings. However, only 30% of physicians use standing orders in their practices.2
Research on standing orders in ambulatory care has focused on immunizations and cancer screening (TABLE). Interventions implementing standing orders typically have multiple components and include staff education, chart flow sheets, and recall-reminders for patients.
TABLE
Effect of standing orders in ambulatory practice
| Disease | Standing order | Improvement in vaccination or screening rate | NNT* |
|---|---|---|---|
| Pneumococcal disease3-5 | Pneumococcal vaccine | Baseline range: 5%-15%; Follow-up range: 25%-28.3% | 3.7-10 |
| Influenza6-8 | Influenza vaccine | Baseline range: 32%-51.4%; Follow-up range: 58%-74.6% | 3.8-4.3 |
| Cancer screening3 | Mammogram | Baseline: 33%; Follow-up: 60% | 3.7 |
| Childhood illnesses9 | Immunizations, ages 2-5 yr | Baseline: 14%; Follow-up: 29% | 6.7 |
| *Number needed to treat (NNT) is based on the number of additional patients who receive an intervention based on the number who may be exposed to the standing order. | |||
Improvement in pneumococcal and flu vaccine rates
Three multicomponent RCTs of outpatient standing orders reported improved pneumococcal vaccination rates.3-5 Similarly, 2 prospective, multicomponent cohort studies6,7 and 1 retrospective study8 found improved rates of influenza vaccination with standing orders.
Childhood vaccination rates also show positive trends
Two controlled trials (1 randomized3 and 1 nonrandomized9) that incorporated standing orders examined their use in childhood immunizations (measles, mumps, and rubella [MMR]; oral polio vaccine [OPV]; Haemophilus influenzae, type b [HIB]; diphtheria and tetanus toxoids with acellular pertussis [DTaP]; and hepatitis B). One trial reported increased use of acute care immunization opportunities;9 the other showed a nonsignificant positive trend in vaccination rates.3
Standing orders increase 1 form of cancer screening, not another
A multicomponent RCT of standing orders for mammography and colorectal cancer screening found a statistically significant increase in screening for mammography, but not colorectal cancer.3
Recommendations
The Society of Adolescent Medicine recommends standing orders for administration of influenza vaccine during flu season.10
The Task Force on Community Preventive Services recommends standing orders for adult vaccinations based on “strong evidence,” but states that insufficient evidence exists to recommend standing orders for childhood vaccinations.11 Vaccines examined include MMR, DTaP, HIB, hepatitis B, and varicella for young children; hepatitis B, varicella, MMR, and tetanus-diphtheria toxoids (Td) for adolescents; Td for adults up to 65 years of age; and influenza and pneumococcal vaccines for adults 65 years and older.
The Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention recommends standing orders for influenza and pneumococcal vaccines.12
RESULTS ARE MIXED. Studies of standing orders tend to examine their effect on compliance with preventive interventions for chronic disease rather than disease outcomes. In the ambulatory setting, they improve rates of influenza vaccination (strength of recommendation [SOR]: C, consistent cohort studies measuring vaccination rates), pneumococcal vaccination (SOR: C, consistent randomized controlled trials [RCTs] measuring vaccination rates), childhood immunizations (SOR: C, inconsistent RCTs measuring vaccination rates), and mammograms (SOR: C, RCT measuring screening rate).
Standing orders don’t improve screening rates for colorectal cancer (SOR: C, RCT measuring screening rate).
Evidence summary
Organizational changes in physician offices can improve delivery of services for preventing and controlling disease.1 Standing orders—typically defined as physician-approved protocols that authorize nurses or other staff members to perform procedures, such as immunizations without direct physician involvement1—are readily applicable in ambulatory settings. However, only 30% of physicians use standing orders in their practices.2
Research on standing orders in ambulatory care has focused on immunizations and cancer screening (TABLE). Interventions implementing standing orders typically have multiple components and include staff education, chart flow sheets, and recall-reminders for patients.
TABLE
Effect of standing orders in ambulatory practice
| Disease | Standing order | Improvement in vaccination or screening rate | NNT* |
|---|---|---|---|
| Pneumococcal disease3-5 | Pneumococcal vaccine | Baseline range: 5%-15%; Follow-up range: 25%-28.3% | 3.7-10 |
| Influenza6-8 | Influenza vaccine | Baseline range: 32%-51.4%; Follow-up range: 58%-74.6% | 3.8-4.3 |
| Cancer screening3 | Mammogram | Baseline: 33%; Follow-up: 60% | 3.7 |
| Childhood illnesses9 | Immunizations, ages 2-5 yr | Baseline: 14%; Follow-up: 29% | 6.7 |
| *Number needed to treat (NNT) is based on the number of additional patients who receive an intervention based on the number who may be exposed to the standing order. | |||
Improvement in pneumococcal and flu vaccine rates
Three multicomponent RCTs of outpatient standing orders reported improved pneumococcal vaccination rates.3-5 Similarly, 2 prospective, multicomponent cohort studies6,7 and 1 retrospective study8 found improved rates of influenza vaccination with standing orders.
Childhood vaccination rates also show positive trends
Two controlled trials (1 randomized3 and 1 nonrandomized9) that incorporated standing orders examined their use in childhood immunizations (measles, mumps, and rubella [MMR]; oral polio vaccine [OPV]; Haemophilus influenzae, type b [HIB]; diphtheria and tetanus toxoids with acellular pertussis [DTaP]; and hepatitis B). One trial reported increased use of acute care immunization opportunities;9 the other showed a nonsignificant positive trend in vaccination rates.3
Standing orders increase 1 form of cancer screening, not another
A multicomponent RCT of standing orders for mammography and colorectal cancer screening found a statistically significant increase in screening for mammography, but not colorectal cancer.3
Recommendations
The Society of Adolescent Medicine recommends standing orders for administration of influenza vaccine during flu season.10
The Task Force on Community Preventive Services recommends standing orders for adult vaccinations based on “strong evidence,” but states that insufficient evidence exists to recommend standing orders for childhood vaccinations.11 Vaccines examined include MMR, DTaP, HIB, hepatitis B, and varicella for young children; hepatitis B, varicella, MMR, and tetanus-diphtheria toxoids (Td) for adolescents; Td for adults up to 65 years of age; and influenza and pneumococcal vaccines for adults 65 years and older.
The Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention recommends standing orders for influenza and pneumococcal vaccines.12
1. Stone EG, Morton SC, Hulscher ME, et al. Interventions that increase use of adult immunization and cancer screening services: a meta-analysis. Ann Intern Med. 2002;136:641-651.
2. Nichol KL, Zimmerman R. Generalist and subspecialist physicians’ knowledge, attitudes, and practices regarding influenza and pneumococcal vaccinations for elderly and other high-risk patients: a nationwide survey. Arch Intern Med. 2001;161:2702-2708.
3. Mold JW, Aspy CA, Nagykaldi Z. Implementation of evidence-based preventive services delivery processes in primary care: an Oklahoma Physicians Resource/Research Network (OKPRN) study. J Am Board Fam Med. 2008;21:334-344.
4. Rhew DC, Glassman PA, Goetz MB. Improving pneumococcal vaccine rates. Nurse protocols versus clinical reminders. J Gen Intern Med. 1999;14:351-356.
5. Herman CJ, Speroff T, Cebul RD. Improving compliance with immunization in the older adult: results of a randomized cohort study. J Am Geriatr Soc. 1994;42:1154-1159.
6. Margolis KL, Nichol KL, Wuorenma J, et al. Exporting a successful influenza vaccination program from a teaching hospital to a community outpatient setting. J Am Geriatr Soc. 1992;40:1021-1023.
7. Nichol KL, Korn JE, Margolis KL, et al. Achieving the national health objective for influenza immunization: success of an institution-wide vaccination program. Am J Med. 1990;89:156-160.
8. Goebel LJ, Neitch SM, Mufson MA. Standing orders in an ambulatory setting increases influenza vaccine usage in older people. J Am Geriatr Soc. 2005;53:1008-1010.
9. Christy C, McConnochie KM, Zernik N, et al. Impact of an algorithm-guided nurse intervention on the use of immunization opportunities. Arch Pediatr Adolesc Med. 1997;151:384-391.
10. Kharbanda EO, Maehr J, Middleman AB, et al. Influenza vaccine: a position statement of The Society for Adolescent Medicine. J Adolesc Health. 2007;41:216-217.
11. Vaccine-preventable diseases: improving vaccination coverage in children adolescents and adults. A report on recommendations from the Task Force on Community Preventive Services. MMWR Recomm Rep. 1999;48(RR-8):1-15.
12. Harper SA, Fukuda K, Uyeki TM, et al. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2004;53 (RR-6):1-40.
1. Stone EG, Morton SC, Hulscher ME, et al. Interventions that increase use of adult immunization and cancer screening services: a meta-analysis. Ann Intern Med. 2002;136:641-651.
2. Nichol KL, Zimmerman R. Generalist and subspecialist physicians’ knowledge, attitudes, and practices regarding influenza and pneumococcal vaccinations for elderly and other high-risk patients: a nationwide survey. Arch Intern Med. 2001;161:2702-2708.
3. Mold JW, Aspy CA, Nagykaldi Z. Implementation of evidence-based preventive services delivery processes in primary care: an Oklahoma Physicians Resource/Research Network (OKPRN) study. J Am Board Fam Med. 2008;21:334-344.
4. Rhew DC, Glassman PA, Goetz MB. Improving pneumococcal vaccine rates. Nurse protocols versus clinical reminders. J Gen Intern Med. 1999;14:351-356.
5. Herman CJ, Speroff T, Cebul RD. Improving compliance with immunization in the older adult: results of a randomized cohort study. J Am Geriatr Soc. 1994;42:1154-1159.
6. Margolis KL, Nichol KL, Wuorenma J, et al. Exporting a successful influenza vaccination program from a teaching hospital to a community outpatient setting. J Am Geriatr Soc. 1992;40:1021-1023.
7. Nichol KL, Korn JE, Margolis KL, et al. Achieving the national health objective for influenza immunization: success of an institution-wide vaccination program. Am J Med. 1990;89:156-160.
8. Goebel LJ, Neitch SM, Mufson MA. Standing orders in an ambulatory setting increases influenza vaccine usage in older people. J Am Geriatr Soc. 2005;53:1008-1010.
9. Christy C, McConnochie KM, Zernik N, et al. Impact of an algorithm-guided nurse intervention on the use of immunization opportunities. Arch Pediatr Adolesc Med. 1997;151:384-391.
10. Kharbanda EO, Maehr J, Middleman AB, et al. Influenza vaccine: a position statement of The Society for Adolescent Medicine. J Adolesc Health. 2007;41:216-217.
11. Vaccine-preventable diseases: improving vaccination coverage in children adolescents and adults. A report on recommendations from the Task Force on Community Preventive Services. MMWR Recomm Rep. 1999;48(RR-8):1-15.
12. Harper SA, Fukuda K, Uyeki TM, et al. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2004;53 (RR-6):1-40.
Evidence-based answers from the Family Physicians Inquiries Network
What illnesses contraindicate immunization?
The Advisory Council on Immunization Practices (ACIP) reports that the only contraindication for all vaccines is a history of severe allergic reaction to a previous vaccine or vaccine constituent (strength of recommendations: C, based predominantly on case series, case reports, and expert opinion).
Vaccination is safe and efficacious in the following situations: during a mild illness (eg, diarrhea, otitis media or other mild upper respiratory infection whether or not the patient has a fever), during antimicrobial therapy, during the convalescent phase of an acute illness, when breastfeeding, and after mild to moderate reactions to a previous dose of vaccine.
Live vaccines (varicella, MMR) should not be used for pregnant women or significantly immunocompromised patients, and may not be effective for patients receiving immunoglobulin therapy. They can be administered to HIV-positive patients who are asymptomatic or not severely immunosuppressed, as determined by age-specific CD4 counts.
Evidence summary
Public misperceptions and provider uncertainty about contraindications create missed opportunities for immunization.1-3 The Centers for Disease Control and Prevention (CDC) defines contraindications as conditions that increase the risk of a serious reaction to vaccination. Precautions are conditions that might increase the risk of a serious reaction, or that diminish vaccine efficiency.4 Recommendations about contraindications and precautions for vaccine administration are partially based on studies of adverse effects (see the TABLE for common situations). Complete information on the contraindications and precautions for all common vaccinations can be accessed at www.cdc.gov/mmwr/preview/mmwrhtml/rr5102a1.htm#tab5.4
Data on vaccination risks are limited by a relative lack of experimental studies. Initial recommendations of the Advisory Council on Immunization Practices have been based on the findings of a 14-member Institute of Medicine (IOM) expert committee and are updated regularly.5-7 The IOM committee reported that because vaccine-related adverse events occur infrequently, available randomized controlled trials were too small to detect differences in incidence.6 Much of the data come from adverse effect surveillance systems, such as the Vaccine Adverse Event Reporting System (VAERS), to which health care providers report possible adverse effects of vaccinations.
Updated contraindications by ACIP to the initial IOM recommendations have also been based on observational reports and studies.4 A recent Cochrane review on acellular pertussis vaccines concluded that the acellular vaccine had fewer adverse effects than the whole-cell version, but did not support any changes in contraindications or precautions.8
TABLE
Contraindications and precautions for vaccine administration
| SITUATION | COMMENTS |
|---|---|
| Mild acute illness (with or without fever) (otitis media, diarrhea, etc) | No contraindication |
| Breastfeeding | No contraindication |
| Serious allergic reaction to vaccine or component (anaphylaxis) | Absolute contraindication |
| Pregnancy | Tetanus and influenza should be kept current |
| No contraindication to give indicated inactivated immunizations | |
| Live vaccines are contraindicated, although no reports of adverse reactions reported | |
| Moderate to severe illness | Temporary precaution—hold until patient improved |
| Encephalopathy <1 week after DTP or DtaP | Pertussis immunization contraindicated |
| Fever >40.5° C or Hypotonic, hyporesponsive episode or Persistent, inconsolable crying >3 hours <48 hours after DTP or DTaP or seizure <3 days after DTP or DTaP | Avoid pertussis, but vaccination may be appropriate during an outbreak |
| Recipients of blood, IVIG, and other antibody-containing products | Hold live vaccines for variable timing depending on dose (see CDC Recommendations) |
| Oral typhoid and yellow fever OK | |
| Chemotherapy or radiotherapy | Give influenza |
| Avoid others (decreased immune response) | |
| Antibacterials | Should not be taken with oral (live) typhoid vaccine (decreased effectiveness) |
| Antivirals against herpes spp | Should not be taken with live varicella vaccine (decreased effectiveness) |
| Postpartum anti-Rho(D) | Simultaneous rubella vaccination effective |
| Hematopoietic Stem Cell transplant recipients | See separate CDC Recommendations* |
| Altered immune status (HIV, solid organ transplant recipients, etc) | See separate CDC Recommendations† |
| Inactivated immunizations are safe, may be less effective | |
| Table based on general recommendations on immunization, MMWR Recomm Rep 2002.4 | |
| *Available at: www.cdc.gov/mmwr/preview/mmwrhtml/rr4910a1.htm | |
| † For HIV, www.cdc.gov/mmwr/preview/mmwrhtml/rr5108a1.htm; for others, www.cdc.gov/mmwr/preview/mmwrhtml/00023141.htm. | |
Recommendations from others
The ACIP recommendations serve as national standards and have been adopted by American Academy of Pediatrics and the American Academy of Family Physicians and are included in most standard reference texts.4,9
Know true contraindications; provide clear, factual information to concerned parents
Rebecca Meriwether, MD
Tulane University, New Orleans, La
Immunizations are among the safest and most cost-effective interventions available in modern medicine. Offices should be organized to assist in assuring delivery of immunizations during preventive, sick, and follow-up visits, and to follow recommended and catch-up schedules to reduce the time patients are susceptible to preventable infectious diseases. Failure to vaccinate due to inappropriate contraindications, particularly mild illness, is a missed opportunity and significant contributor to under-immunization. Know and observe true contraindications and provide clear, factual information to parents concerned about vaccine risks. When temporarily delaying vaccination is prudent—eg, with evolving neurologic conditions and moderate to severe illness—scheduling a return visit for immunizations and documenting the intention to vaccinate at the next visit are strategies to reduce the risk that catch-up immunization will be forgotten.
1. Wald ER, Dashefsky B, Byers C, Guerra N, Taylor F. Frequency and severity of infections in day care. J Pediatr 1988;112:540-546.
2. Szilagyi PG, Rodewald LE. Missed opportunities for immunizations: a review of the evidence. J Public Health Manag Pract 1996;2:18-25.
3. Farizo KM, Stehr-Green PA, Markowitz LE, Patriarca PA. Vaccination levels and missed opportunities for measles vaccination: a record audit in a public pediatric clinic. Pediatrics 1992;89:589-592.
4. General recommendations on immunization: recommendations of the Advisory Committee on Immunization Practices and the American Academy of Family Physicians. MMWR Recomm Rep 2002;51(RR-2):1-35.
5. Howson CP, Howe CJ, Fineberg HV, eds. Adverse Effects of Pertussis and Rubella Vaccines. Washington, DC: National Academy Press, last updated 1991. Available at: www.nap.edu/books/0309044995/html/index.html. Accessed on June 10, 2005.
6. Stratton KR, Howe CJ, Johnston RB, eds. Adverse Events Associated with Childhood Vaccines: Evidence Bearing on Causality. Washington, DC: National Academy Press, Last updated 1994. Available at: www.nap.edu/catalog/2138.html. Accessed on June 10, 2005.
7. Update: vaccine side effects, adverse reactions, contraindications, and precautions: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 1996;45(RR-12):1-35.
8. Tinnion ON, Hanlon M. Acellular vaccines for preventing whooping cough in children. Cochrane Database Syst Rev 2000(2);CD001478.-
9. American Academy of Pediatrics. Active and Passive Immunization. In: Pickering LK, ed. Red Book: 2003 Report of the Committee on Infectious Diseases. 26th ed. Elk Grove Village, Ill: American Academy of Pediatrics; 2003;46-49.
The Advisory Council on Immunization Practices (ACIP) reports that the only contraindication for all vaccines is a history of severe allergic reaction to a previous vaccine or vaccine constituent (strength of recommendations: C, based predominantly on case series, case reports, and expert opinion).
Vaccination is safe and efficacious in the following situations: during a mild illness (eg, diarrhea, otitis media or other mild upper respiratory infection whether or not the patient has a fever), during antimicrobial therapy, during the convalescent phase of an acute illness, when breastfeeding, and after mild to moderate reactions to a previous dose of vaccine.
Live vaccines (varicella, MMR) should not be used for pregnant women or significantly immunocompromised patients, and may not be effective for patients receiving immunoglobulin therapy. They can be administered to HIV-positive patients who are asymptomatic or not severely immunosuppressed, as determined by age-specific CD4 counts.
Evidence summary
Public misperceptions and provider uncertainty about contraindications create missed opportunities for immunization.1-3 The Centers for Disease Control and Prevention (CDC) defines contraindications as conditions that increase the risk of a serious reaction to vaccination. Precautions are conditions that might increase the risk of a serious reaction, or that diminish vaccine efficiency.4 Recommendations about contraindications and precautions for vaccine administration are partially based on studies of adverse effects (see the TABLE for common situations). Complete information on the contraindications and precautions for all common vaccinations can be accessed at www.cdc.gov/mmwr/preview/mmwrhtml/rr5102a1.htm#tab5.4
Data on vaccination risks are limited by a relative lack of experimental studies. Initial recommendations of the Advisory Council on Immunization Practices have been based on the findings of a 14-member Institute of Medicine (IOM) expert committee and are updated regularly.5-7 The IOM committee reported that because vaccine-related adverse events occur infrequently, available randomized controlled trials were too small to detect differences in incidence.6 Much of the data come from adverse effect surveillance systems, such as the Vaccine Adverse Event Reporting System (VAERS), to which health care providers report possible adverse effects of vaccinations.
Updated contraindications by ACIP to the initial IOM recommendations have also been based on observational reports and studies.4 A recent Cochrane review on acellular pertussis vaccines concluded that the acellular vaccine had fewer adverse effects than the whole-cell version, but did not support any changes in contraindications or precautions.8
TABLE
Contraindications and precautions for vaccine administration
| SITUATION | COMMENTS |
|---|---|
| Mild acute illness (with or without fever) (otitis media, diarrhea, etc) | No contraindication |
| Breastfeeding | No contraindication |
| Serious allergic reaction to vaccine or component (anaphylaxis) | Absolute contraindication |
| Pregnancy | Tetanus and influenza should be kept current |
| No contraindication to give indicated inactivated immunizations | |
| Live vaccines are contraindicated, although no reports of adverse reactions reported | |
| Moderate to severe illness | Temporary precaution—hold until patient improved |
| Encephalopathy <1 week after DTP or DtaP | Pertussis immunization contraindicated |
| Fever >40.5° C or Hypotonic, hyporesponsive episode or Persistent, inconsolable crying >3 hours <48 hours after DTP or DTaP or seizure <3 days after DTP or DTaP | Avoid pertussis, but vaccination may be appropriate during an outbreak |
| Recipients of blood, IVIG, and other antibody-containing products | Hold live vaccines for variable timing depending on dose (see CDC Recommendations) |
| Oral typhoid and yellow fever OK | |
| Chemotherapy or radiotherapy | Give influenza |
| Avoid others (decreased immune response) | |
| Antibacterials | Should not be taken with oral (live) typhoid vaccine (decreased effectiveness) |
| Antivirals against herpes spp | Should not be taken with live varicella vaccine (decreased effectiveness) |
| Postpartum anti-Rho(D) | Simultaneous rubella vaccination effective |
| Hematopoietic Stem Cell transplant recipients | See separate CDC Recommendations* |
| Altered immune status (HIV, solid organ transplant recipients, etc) | See separate CDC Recommendations† |
| Inactivated immunizations are safe, may be less effective | |
| Table based on general recommendations on immunization, MMWR Recomm Rep 2002.4 | |
| *Available at: www.cdc.gov/mmwr/preview/mmwrhtml/rr4910a1.htm | |
| † For HIV, www.cdc.gov/mmwr/preview/mmwrhtml/rr5108a1.htm; for others, www.cdc.gov/mmwr/preview/mmwrhtml/00023141.htm. | |
Recommendations from others
The ACIP recommendations serve as national standards and have been adopted by American Academy of Pediatrics and the American Academy of Family Physicians and are included in most standard reference texts.4,9
Know true contraindications; provide clear, factual information to concerned parents
Rebecca Meriwether, MD
Tulane University, New Orleans, La
Immunizations are among the safest and most cost-effective interventions available in modern medicine. Offices should be organized to assist in assuring delivery of immunizations during preventive, sick, and follow-up visits, and to follow recommended and catch-up schedules to reduce the time patients are susceptible to preventable infectious diseases. Failure to vaccinate due to inappropriate contraindications, particularly mild illness, is a missed opportunity and significant contributor to under-immunization. Know and observe true contraindications and provide clear, factual information to parents concerned about vaccine risks. When temporarily delaying vaccination is prudent—eg, with evolving neurologic conditions and moderate to severe illness—scheduling a return visit for immunizations and documenting the intention to vaccinate at the next visit are strategies to reduce the risk that catch-up immunization will be forgotten.
The Advisory Council on Immunization Practices (ACIP) reports that the only contraindication for all vaccines is a history of severe allergic reaction to a previous vaccine or vaccine constituent (strength of recommendations: C, based predominantly on case series, case reports, and expert opinion).
Vaccination is safe and efficacious in the following situations: during a mild illness (eg, diarrhea, otitis media or other mild upper respiratory infection whether or not the patient has a fever), during antimicrobial therapy, during the convalescent phase of an acute illness, when breastfeeding, and after mild to moderate reactions to a previous dose of vaccine.
Live vaccines (varicella, MMR) should not be used for pregnant women or significantly immunocompromised patients, and may not be effective for patients receiving immunoglobulin therapy. They can be administered to HIV-positive patients who are asymptomatic or not severely immunosuppressed, as determined by age-specific CD4 counts.
Evidence summary
Public misperceptions and provider uncertainty about contraindications create missed opportunities for immunization.1-3 The Centers for Disease Control and Prevention (CDC) defines contraindications as conditions that increase the risk of a serious reaction to vaccination. Precautions are conditions that might increase the risk of a serious reaction, or that diminish vaccine efficiency.4 Recommendations about contraindications and precautions for vaccine administration are partially based on studies of adverse effects (see the TABLE for common situations). Complete information on the contraindications and precautions for all common vaccinations can be accessed at www.cdc.gov/mmwr/preview/mmwrhtml/rr5102a1.htm#tab5.4
Data on vaccination risks are limited by a relative lack of experimental studies. Initial recommendations of the Advisory Council on Immunization Practices have been based on the findings of a 14-member Institute of Medicine (IOM) expert committee and are updated regularly.5-7 The IOM committee reported that because vaccine-related adverse events occur infrequently, available randomized controlled trials were too small to detect differences in incidence.6 Much of the data come from adverse effect surveillance systems, such as the Vaccine Adverse Event Reporting System (VAERS), to which health care providers report possible adverse effects of vaccinations.
Updated contraindications by ACIP to the initial IOM recommendations have also been based on observational reports and studies.4 A recent Cochrane review on acellular pertussis vaccines concluded that the acellular vaccine had fewer adverse effects than the whole-cell version, but did not support any changes in contraindications or precautions.8
TABLE
Contraindications and precautions for vaccine administration
| SITUATION | COMMENTS |
|---|---|
| Mild acute illness (with or without fever) (otitis media, diarrhea, etc) | No contraindication |
| Breastfeeding | No contraindication |
| Serious allergic reaction to vaccine or component (anaphylaxis) | Absolute contraindication |
| Pregnancy | Tetanus and influenza should be kept current |
| No contraindication to give indicated inactivated immunizations | |
| Live vaccines are contraindicated, although no reports of adverse reactions reported | |
| Moderate to severe illness | Temporary precaution—hold until patient improved |
| Encephalopathy <1 week after DTP or DtaP | Pertussis immunization contraindicated |
| Fever >40.5° C or Hypotonic, hyporesponsive episode or Persistent, inconsolable crying >3 hours <48 hours after DTP or DTaP or seizure <3 days after DTP or DTaP | Avoid pertussis, but vaccination may be appropriate during an outbreak |
| Recipients of blood, IVIG, and other antibody-containing products | Hold live vaccines for variable timing depending on dose (see CDC Recommendations) |
| Oral typhoid and yellow fever OK | |
| Chemotherapy or radiotherapy | Give influenza |
| Avoid others (decreased immune response) | |
| Antibacterials | Should not be taken with oral (live) typhoid vaccine (decreased effectiveness) |
| Antivirals against herpes spp | Should not be taken with live varicella vaccine (decreased effectiveness) |
| Postpartum anti-Rho(D) | Simultaneous rubella vaccination effective |
| Hematopoietic Stem Cell transplant recipients | See separate CDC Recommendations* |
| Altered immune status (HIV, solid organ transplant recipients, etc) | See separate CDC Recommendations† |
| Inactivated immunizations are safe, may be less effective | |
| Table based on general recommendations on immunization, MMWR Recomm Rep 2002.4 | |
| *Available at: www.cdc.gov/mmwr/preview/mmwrhtml/rr4910a1.htm | |
| † For HIV, www.cdc.gov/mmwr/preview/mmwrhtml/rr5108a1.htm; for others, www.cdc.gov/mmwr/preview/mmwrhtml/00023141.htm. | |
Recommendations from others
The ACIP recommendations serve as national standards and have been adopted by American Academy of Pediatrics and the American Academy of Family Physicians and are included in most standard reference texts.4,9
Know true contraindications; provide clear, factual information to concerned parents
Rebecca Meriwether, MD
Tulane University, New Orleans, La
Immunizations are among the safest and most cost-effective interventions available in modern medicine. Offices should be organized to assist in assuring delivery of immunizations during preventive, sick, and follow-up visits, and to follow recommended and catch-up schedules to reduce the time patients are susceptible to preventable infectious diseases. Failure to vaccinate due to inappropriate contraindications, particularly mild illness, is a missed opportunity and significant contributor to under-immunization. Know and observe true contraindications and provide clear, factual information to parents concerned about vaccine risks. When temporarily delaying vaccination is prudent—eg, with evolving neurologic conditions and moderate to severe illness—scheduling a return visit for immunizations and documenting the intention to vaccinate at the next visit are strategies to reduce the risk that catch-up immunization will be forgotten.
1. Wald ER, Dashefsky B, Byers C, Guerra N, Taylor F. Frequency and severity of infections in day care. J Pediatr 1988;112:540-546.
2. Szilagyi PG, Rodewald LE. Missed opportunities for immunizations: a review of the evidence. J Public Health Manag Pract 1996;2:18-25.
3. Farizo KM, Stehr-Green PA, Markowitz LE, Patriarca PA. Vaccination levels and missed opportunities for measles vaccination: a record audit in a public pediatric clinic. Pediatrics 1992;89:589-592.
4. General recommendations on immunization: recommendations of the Advisory Committee on Immunization Practices and the American Academy of Family Physicians. MMWR Recomm Rep 2002;51(RR-2):1-35.
5. Howson CP, Howe CJ, Fineberg HV, eds. Adverse Effects of Pertussis and Rubella Vaccines. Washington, DC: National Academy Press, last updated 1991. Available at: www.nap.edu/books/0309044995/html/index.html. Accessed on June 10, 2005.
6. Stratton KR, Howe CJ, Johnston RB, eds. Adverse Events Associated with Childhood Vaccines: Evidence Bearing on Causality. Washington, DC: National Academy Press, Last updated 1994. Available at: www.nap.edu/catalog/2138.html. Accessed on June 10, 2005.
7. Update: vaccine side effects, adverse reactions, contraindications, and precautions: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 1996;45(RR-12):1-35.
8. Tinnion ON, Hanlon M. Acellular vaccines for preventing whooping cough in children. Cochrane Database Syst Rev 2000(2);CD001478.-
9. American Academy of Pediatrics. Active and Passive Immunization. In: Pickering LK, ed. Red Book: 2003 Report of the Committee on Infectious Diseases. 26th ed. Elk Grove Village, Ill: American Academy of Pediatrics; 2003;46-49.
1. Wald ER, Dashefsky B, Byers C, Guerra N, Taylor F. Frequency and severity of infections in day care. J Pediatr 1988;112:540-546.
2. Szilagyi PG, Rodewald LE. Missed opportunities for immunizations: a review of the evidence. J Public Health Manag Pract 1996;2:18-25.
3. Farizo KM, Stehr-Green PA, Markowitz LE, Patriarca PA. Vaccination levels and missed opportunities for measles vaccination: a record audit in a public pediatric clinic. Pediatrics 1992;89:589-592.
4. General recommendations on immunization: recommendations of the Advisory Committee on Immunization Practices and the American Academy of Family Physicians. MMWR Recomm Rep 2002;51(RR-2):1-35.
5. Howson CP, Howe CJ, Fineberg HV, eds. Adverse Effects of Pertussis and Rubella Vaccines. Washington, DC: National Academy Press, last updated 1991. Available at: www.nap.edu/books/0309044995/html/index.html. Accessed on June 10, 2005.
6. Stratton KR, Howe CJ, Johnston RB, eds. Adverse Events Associated with Childhood Vaccines: Evidence Bearing on Causality. Washington, DC: National Academy Press, Last updated 1994. Available at: www.nap.edu/catalog/2138.html. Accessed on June 10, 2005.
7. Update: vaccine side effects, adverse reactions, contraindications, and precautions: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 1996;45(RR-12):1-35.
8. Tinnion ON, Hanlon M. Acellular vaccines for preventing whooping cough in children. Cochrane Database Syst Rev 2000(2);CD001478.-
9. American Academy of Pediatrics. Active and Passive Immunization. In: Pickering LK, ed. Red Book: 2003 Report of the Committee on Infectious Diseases. 26th ed. Elk Grove Village, Ill: American Academy of Pediatrics; 2003;46-49.
Evidence-based answers from the Family Physicians Inquiries Network
Should the varicella vaccine be given to all children to prevent chickenpox?
EVIDENCE-BASED ANSWER
Healthy, unimmunized children who have not had varicella infection should be vaccinated (strength of recommendation: A, based on randomized controlled trials). Use of the vaccine in immunocompromised children is still being studied and has not been approved by the Food and Drug Administration (FDA).
Evidence summary
Before the introduction of the varicella vaccine, almost 4 million cases of chickenpox occurred each year in the United States, resulting in 11,000 hospitalizations and 100 deaths.1 Varicella is the leading cause of vaccine-preventable death in children.2
In a search of the literature from 1966 to 2000, a systematic review identified 24 randomized controlled trials and 18 cohort studies of varicella vaccination.3 In children aged 10 months to 14 years, 1 randomized controlled trial found protective efficacy of 100% over 9 months and 98% over 7 years.4 A second trial showed efficacy of 72% over 29 months.5Cohort studies of children report that the vaccine is 84% to 86% effective in preventing varicella and 100% effective in preventing moderate to severe infections.3
Cumulative results of all studies show the number needed to vaccinate to prevent 1 case of varicella ranges from 5.5 to 11.8, and the number needed to prevent 1 complicated case ranges from 550 to 1180.
No direct evidence supports or refutes a reduction in varicella mortality or rates of hospitalization due to vaccination. Randomized controlled trials show no increase in rates of fever or rash among those receiving vaccine; however, cohort studies report fever (0%–36%), local injection site reactions (7%–30%), and rash (5%).3 No clinical trials have shown transmission of vaccine-related varicella zoster virus in immunocompetent patients, and only 3 proven cases of transmission of vaccine virus to susceptible contacts have been documented.6 Some evidence suggests the incidence of herpes zoster is reduced in immunocompromised vaccine recipients, but long-term observation is needed to assess the effect on healthy recipients.7
One concern about the vaccine is that waning immunity over time could result in increased incidence of varicella infection during adulthood. While existing studies document persistence of antibodies for up to 20 years following immunization,3 long-term effectiveness should continue to be monitored.
The FDA has not approved this live-virus vaccine for use in pregnant women and immunocom-promised persons, including transplant recipients and persons receiving corticosteroid therapy. However, the vaccine has been very well-studied in children with leukemia. A review of these studies found that optimal seroconversion requires 2 sequential vaccine doses (86% efficacy). A rash of varying severity was the predominant adverse event in 20% to 50% of vacinees.7 Study of vaccine use in other immunocompromised children has been limited. Early results from a trial in HIV-infected children who were not severely immunocompromised suggests similar tolerance and efficacy compared with children without HIV.8 A systemic review of cost-effectiveness of varicella vaccine is based predominantly on mathematical models.9These models show societal savings due to decrease in unproductive days for parents, but fail to demonstrate actual healthcare savings.
Recommendations from others
The American Academy of Pediatrics (AAP), Advisory Committee on Immunization Practices (ACIP), and American Academy of Family Medicine all recommend vaccinating unimmunized children aged 12 months and older who have not had varicella infection, and not vaccinating children with cellular immunodeficiencies.2,10,11 The AAP suggests the vaccine could be considered for children with acute lymphocytic leukemia and for HIV-infected children with mild or no signs or symptoms. The ACIP guidelines are similar, with the addition that children with impaired humoral immunity may now be vaccinated.
Encourage varicella vaccination, except for the immunocompromised
Kristen Rundell, MD
University of Colorado Health Sciences Center, Denver
For many parents, vaccination decisions are made based on school district requirements. Varicella zoster vaccine is an exception to that rule. Parents can choose to immunize their child at 12 months or wait and let nature take its course—hopefully before the child starts kindergarten. The major concern with the vaccine has been its long-term efficacy. Although no one knows for sure how long immunity is sustained, studies show that detectable antibodies are present for up to 20 years.
As a parent and physician, my decision to vaccinate my daughter was made after I witnessed an 8-year-old boy in the emergency room with respiratory distress secondary to complications from chickenpox. This experience reinforced for me that chickenpox is a life-threatening disease. The effects of chickenpox include scarring as well as time away from work for parents. I therefore encourage varicella vaccination for my patients, with the only exception being those who are immunocompromised, for whom we have no data.
To the question of whether we should we vaccinate children to prevent chickenpox, I give a resounding “yes.”
1. Arvin AM. Varicella vaccine—the first six years. N Engl J Med 2001;344:1007-1009.
2. Centers for Disease Control and Prevention. Prevention of varicella. Update recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 1999;48(RR-6):1-5.
3. Skull SA, Wang EE. Varicella vaccination—a critical review of the evidence. Arch Dis Child 2001;85:83-90.
4. Weibel RE, Neff BJ, Kuter BJ, et al. Live attenuated varicella vaccine. Efficacy trial in healthy children. N Eng J Med 1984;310:1409-1415.
5. Varis T, Vesikari T. Efficacy of high-titer live attenuated varicella vaccine in healthy young children. J Infect Dis 1996;174(suppl 3):S330-S334.
6. Wise RP, Salive ME, Braun MM, et al. Postlicensure safety surveillance for varicella vaccine. JAMA 2000;284:1271-1279.
7. Gershon AA, LaRussa P, Steinberg S. The varicella vaccine. Clinical trials in immunocompromised individuals. Infect Dis Clin North Am 1996;10:583-594.
8. Levin MJ, Gershon AA, Weinberg A, et al. Immunization of HIV-infected children with varicella vaccine. J Pediatr 2001;139:305-310.
9. Rothberg M, Bennish ML, Kao JS, Wong JB. Do the benefits of varicella vaccination outweigh the risks? A decision-analytical model for policymakers and pediatricians. Clin Infect Dis 2002;34:885-894.
10. American. Academy of Family Practice. Periodic Health Examinations. Revision 5.3. Leawood, Kansas: AAFP; 2002.
11. American Academy of Pediatrics. Committee on Infectious Diseases. Varicella vaccine update. Pediatrics 2000;105:136-141.
EVIDENCE-BASED ANSWER
Healthy, unimmunized children who have not had varicella infection should be vaccinated (strength of recommendation: A, based on randomized controlled trials). Use of the vaccine in immunocompromised children is still being studied and has not been approved by the Food and Drug Administration (FDA).
Evidence summary
Before the introduction of the varicella vaccine, almost 4 million cases of chickenpox occurred each year in the United States, resulting in 11,000 hospitalizations and 100 deaths.1 Varicella is the leading cause of vaccine-preventable death in children.2
In a search of the literature from 1966 to 2000, a systematic review identified 24 randomized controlled trials and 18 cohort studies of varicella vaccination.3 In children aged 10 months to 14 years, 1 randomized controlled trial found protective efficacy of 100% over 9 months and 98% over 7 years.4 A second trial showed efficacy of 72% over 29 months.5Cohort studies of children report that the vaccine is 84% to 86% effective in preventing varicella and 100% effective in preventing moderate to severe infections.3
Cumulative results of all studies show the number needed to vaccinate to prevent 1 case of varicella ranges from 5.5 to 11.8, and the number needed to prevent 1 complicated case ranges from 550 to 1180.
No direct evidence supports or refutes a reduction in varicella mortality or rates of hospitalization due to vaccination. Randomized controlled trials show no increase in rates of fever or rash among those receiving vaccine; however, cohort studies report fever (0%–36%), local injection site reactions (7%–30%), and rash (5%).3 No clinical trials have shown transmission of vaccine-related varicella zoster virus in immunocompetent patients, and only 3 proven cases of transmission of vaccine virus to susceptible contacts have been documented.6 Some evidence suggests the incidence of herpes zoster is reduced in immunocompromised vaccine recipients, but long-term observation is needed to assess the effect on healthy recipients.7
One concern about the vaccine is that waning immunity over time could result in increased incidence of varicella infection during adulthood. While existing studies document persistence of antibodies for up to 20 years following immunization,3 long-term effectiveness should continue to be monitored.
The FDA has not approved this live-virus vaccine for use in pregnant women and immunocom-promised persons, including transplant recipients and persons receiving corticosteroid therapy. However, the vaccine has been very well-studied in children with leukemia. A review of these studies found that optimal seroconversion requires 2 sequential vaccine doses (86% efficacy). A rash of varying severity was the predominant adverse event in 20% to 50% of vacinees.7 Study of vaccine use in other immunocompromised children has been limited. Early results from a trial in HIV-infected children who were not severely immunocompromised suggests similar tolerance and efficacy compared with children without HIV.8 A systemic review of cost-effectiveness of varicella vaccine is based predominantly on mathematical models.9These models show societal savings due to decrease in unproductive days for parents, but fail to demonstrate actual healthcare savings.
Recommendations from others
The American Academy of Pediatrics (AAP), Advisory Committee on Immunization Practices (ACIP), and American Academy of Family Medicine all recommend vaccinating unimmunized children aged 12 months and older who have not had varicella infection, and not vaccinating children with cellular immunodeficiencies.2,10,11 The AAP suggests the vaccine could be considered for children with acute lymphocytic leukemia and for HIV-infected children with mild or no signs or symptoms. The ACIP guidelines are similar, with the addition that children with impaired humoral immunity may now be vaccinated.
Encourage varicella vaccination, except for the immunocompromised
Kristen Rundell, MD
University of Colorado Health Sciences Center, Denver
For many parents, vaccination decisions are made based on school district requirements. Varicella zoster vaccine is an exception to that rule. Parents can choose to immunize their child at 12 months or wait and let nature take its course—hopefully before the child starts kindergarten. The major concern with the vaccine has been its long-term efficacy. Although no one knows for sure how long immunity is sustained, studies show that detectable antibodies are present for up to 20 years.
As a parent and physician, my decision to vaccinate my daughter was made after I witnessed an 8-year-old boy in the emergency room with respiratory distress secondary to complications from chickenpox. This experience reinforced for me that chickenpox is a life-threatening disease. The effects of chickenpox include scarring as well as time away from work for parents. I therefore encourage varicella vaccination for my patients, with the only exception being those who are immunocompromised, for whom we have no data.
To the question of whether we should we vaccinate children to prevent chickenpox, I give a resounding “yes.”
EVIDENCE-BASED ANSWER
Healthy, unimmunized children who have not had varicella infection should be vaccinated (strength of recommendation: A, based on randomized controlled trials). Use of the vaccine in immunocompromised children is still being studied and has not been approved by the Food and Drug Administration (FDA).
Evidence summary
Before the introduction of the varicella vaccine, almost 4 million cases of chickenpox occurred each year in the United States, resulting in 11,000 hospitalizations and 100 deaths.1 Varicella is the leading cause of vaccine-preventable death in children.2
In a search of the literature from 1966 to 2000, a systematic review identified 24 randomized controlled trials and 18 cohort studies of varicella vaccination.3 In children aged 10 months to 14 years, 1 randomized controlled trial found protective efficacy of 100% over 9 months and 98% over 7 years.4 A second trial showed efficacy of 72% over 29 months.5Cohort studies of children report that the vaccine is 84% to 86% effective in preventing varicella and 100% effective in preventing moderate to severe infections.3
Cumulative results of all studies show the number needed to vaccinate to prevent 1 case of varicella ranges from 5.5 to 11.8, and the number needed to prevent 1 complicated case ranges from 550 to 1180.
No direct evidence supports or refutes a reduction in varicella mortality or rates of hospitalization due to vaccination. Randomized controlled trials show no increase in rates of fever or rash among those receiving vaccine; however, cohort studies report fever (0%–36%), local injection site reactions (7%–30%), and rash (5%).3 No clinical trials have shown transmission of vaccine-related varicella zoster virus in immunocompetent patients, and only 3 proven cases of transmission of vaccine virus to susceptible contacts have been documented.6 Some evidence suggests the incidence of herpes zoster is reduced in immunocompromised vaccine recipients, but long-term observation is needed to assess the effect on healthy recipients.7
One concern about the vaccine is that waning immunity over time could result in increased incidence of varicella infection during adulthood. While existing studies document persistence of antibodies for up to 20 years following immunization,3 long-term effectiveness should continue to be monitored.
The FDA has not approved this live-virus vaccine for use in pregnant women and immunocom-promised persons, including transplant recipients and persons receiving corticosteroid therapy. However, the vaccine has been very well-studied in children with leukemia. A review of these studies found that optimal seroconversion requires 2 sequential vaccine doses (86% efficacy). A rash of varying severity was the predominant adverse event in 20% to 50% of vacinees.7 Study of vaccine use in other immunocompromised children has been limited. Early results from a trial in HIV-infected children who were not severely immunocompromised suggests similar tolerance and efficacy compared with children without HIV.8 A systemic review of cost-effectiveness of varicella vaccine is based predominantly on mathematical models.9These models show societal savings due to decrease in unproductive days for parents, but fail to demonstrate actual healthcare savings.
Recommendations from others
The American Academy of Pediatrics (AAP), Advisory Committee on Immunization Practices (ACIP), and American Academy of Family Medicine all recommend vaccinating unimmunized children aged 12 months and older who have not had varicella infection, and not vaccinating children with cellular immunodeficiencies.2,10,11 The AAP suggests the vaccine could be considered for children with acute lymphocytic leukemia and for HIV-infected children with mild or no signs or symptoms. The ACIP guidelines are similar, with the addition that children with impaired humoral immunity may now be vaccinated.
Encourage varicella vaccination, except for the immunocompromised
Kristen Rundell, MD
University of Colorado Health Sciences Center, Denver
For many parents, vaccination decisions are made based on school district requirements. Varicella zoster vaccine is an exception to that rule. Parents can choose to immunize their child at 12 months or wait and let nature take its course—hopefully before the child starts kindergarten. The major concern with the vaccine has been its long-term efficacy. Although no one knows for sure how long immunity is sustained, studies show that detectable antibodies are present for up to 20 years.
As a parent and physician, my decision to vaccinate my daughter was made after I witnessed an 8-year-old boy in the emergency room with respiratory distress secondary to complications from chickenpox. This experience reinforced for me that chickenpox is a life-threatening disease. The effects of chickenpox include scarring as well as time away from work for parents. I therefore encourage varicella vaccination for my patients, with the only exception being those who are immunocompromised, for whom we have no data.
To the question of whether we should we vaccinate children to prevent chickenpox, I give a resounding “yes.”
1. Arvin AM. Varicella vaccine—the first six years. N Engl J Med 2001;344:1007-1009.
2. Centers for Disease Control and Prevention. Prevention of varicella. Update recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 1999;48(RR-6):1-5.
3. Skull SA, Wang EE. Varicella vaccination—a critical review of the evidence. Arch Dis Child 2001;85:83-90.
4. Weibel RE, Neff BJ, Kuter BJ, et al. Live attenuated varicella vaccine. Efficacy trial in healthy children. N Eng J Med 1984;310:1409-1415.
5. Varis T, Vesikari T. Efficacy of high-titer live attenuated varicella vaccine in healthy young children. J Infect Dis 1996;174(suppl 3):S330-S334.
6. Wise RP, Salive ME, Braun MM, et al. Postlicensure safety surveillance for varicella vaccine. JAMA 2000;284:1271-1279.
7. Gershon AA, LaRussa P, Steinberg S. The varicella vaccine. Clinical trials in immunocompromised individuals. Infect Dis Clin North Am 1996;10:583-594.
8. Levin MJ, Gershon AA, Weinberg A, et al. Immunization of HIV-infected children with varicella vaccine. J Pediatr 2001;139:305-310.
9. Rothberg M, Bennish ML, Kao JS, Wong JB. Do the benefits of varicella vaccination outweigh the risks? A decision-analytical model for policymakers and pediatricians. Clin Infect Dis 2002;34:885-894.
10. American. Academy of Family Practice. Periodic Health Examinations. Revision 5.3. Leawood, Kansas: AAFP; 2002.
11. American Academy of Pediatrics. Committee on Infectious Diseases. Varicella vaccine update. Pediatrics 2000;105:136-141.
1. Arvin AM. Varicella vaccine—the first six years. N Engl J Med 2001;344:1007-1009.
2. Centers for Disease Control and Prevention. Prevention of varicella. Update recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 1999;48(RR-6):1-5.
3. Skull SA, Wang EE. Varicella vaccination—a critical review of the evidence. Arch Dis Child 2001;85:83-90.
4. Weibel RE, Neff BJ, Kuter BJ, et al. Live attenuated varicella vaccine. Efficacy trial in healthy children. N Eng J Med 1984;310:1409-1415.
5. Varis T, Vesikari T. Efficacy of high-titer live attenuated varicella vaccine in healthy young children. J Infect Dis 1996;174(suppl 3):S330-S334.
6. Wise RP, Salive ME, Braun MM, et al. Postlicensure safety surveillance for varicella vaccine. JAMA 2000;284:1271-1279.
7. Gershon AA, LaRussa P, Steinberg S. The varicella vaccine. Clinical trials in immunocompromised individuals. Infect Dis Clin North Am 1996;10:583-594.
8. Levin MJ, Gershon AA, Weinberg A, et al. Immunization of HIV-infected children with varicella vaccine. J Pediatr 2001;139:305-310.
9. Rothberg M, Bennish ML, Kao JS, Wong JB. Do the benefits of varicella vaccination outweigh the risks? A decision-analytical model for policymakers and pediatricians. Clin Infect Dis 2002;34:885-894.
10. American. Academy of Family Practice. Periodic Health Examinations. Revision 5.3. Leawood, Kansas: AAFP; 2002.
11. American Academy of Pediatrics. Committee on Infectious Diseases. Varicella vaccine update. Pediatrics 2000;105:136-141.
Evidence-based answers from the Family Physicians Inquiries Network