Tags

Type your tag names separated by a space and hit enter

An elementary school outbreak of varicella attributed to vaccine failure: policy implications.
J Infect Dis. 2004 Aug 01; 190(3):477-83.JI

Abstract

BACKGROUND

Since licensure in the United States, studies have shown that varicella vaccine's overall effectiveness ranges from 44% to 100%, with substantial protection against moderate and severe varicella; however, breakthrough illness has been documented in up to 56% of vaccinated individuals.

METHODS

A varicella outbreak occurred in a Minnesota school with 319 students. Phone surveys were conducted with students' parents. Information was collected on students who had recent varicella infections, including onset date, rash characteristics, duration, and underlying medical conditions.

RESULTS

Fifty-four cases occurred after a primary breakthrough case. Twenty-nine (53%) students had been vaccinated. Unvaccinated students had an increased risk of moderate varicella, compared with vaccinated students (relative risk [RR], 4.4 [95% confidence interval [CI], 2.2-9.1]; P<.001). The vaccine was 56% effective at preventing any varicella and 90% effective against moderate illness. Students vaccinated >or=5 years before the outbreak had a greater risk of breakthrough varicella than did those vaccinated within <or=4 years (RR, 2.6 [95% CI, 1.3-5.4]; P<.01).

CONCLUSIONS

Vaccinated students presented with milder varicella symptoms than did unvaccinated students. Individuals with breakthrough illness can be highly infectious. Time since varicella vaccination was associated with illness. Despite 29 breakthrough cases, the varicella vaccine conferred a high degree of protection against moderate illness.

Authors+Show Affiliations

Lee BR
Immunization, Tuberculosis, and International Health Section, Infectious Disease Epidemiology, Prevention, and Control Division, Minnesota Department of Health, Minneapolis 55414, USA. brian.lee@health.state.mn.us
Feaver SL
No affiliation info available
Miller CA
No affiliation info available
Hedberg CW
No affiliation info available
Ehresmann KR
No affiliation info available

MeSH

ChickenpoxChickenpox VaccineChildChild, PreschoolDisease OutbreaksFemaleHealth PolicyHerpesvirus 3, HumanHumansMaleMinnesotaRisk FactorsSchoolsSeverity of Illness IndexTreatment FailureVaccination

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

15243919

Citation

Lee, Brian R., et al. "An Elementary School Outbreak of Varicella Attributed to Vaccine Failure: Policy Implications." The Journal of Infectious Diseases, vol. 190, no. 3, 2004, pp. 477-83.
Lee BR, Feaver SL, Miller CA, et al. An elementary school outbreak of varicella attributed to vaccine failure: policy implications. J Infect Dis. 2004;190(3):477-83.
Lee, B. R., Feaver, S. L., Miller, C. A., Hedberg, C. W., & Ehresmann, K. R. (2004). An elementary school outbreak of varicella attributed to vaccine failure: policy implications. The Journal of Infectious Diseases, 190(3), 477-83.
Lee BR, et al. An Elementary School Outbreak of Varicella Attributed to Vaccine Failure: Policy Implications. J Infect Dis. 2004 Aug 1;190(3):477-83. PubMed PMID: 15243919.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - An elementary school outbreak of varicella attributed to vaccine failure: policy implications. AU - Lee,Brian R, AU - Feaver,Shelly L, AU - Miller,Claudia A, AU - Hedberg,Craig W, AU - Ehresmann,Kristen R, Y1 - 2004/06/29/ PY - 2004/01/06/received PY - 2004/02/02/accepted PY - 2004/7/10/pubmed PY - 2004/8/25/medline PY - 2004/7/10/entrez SP - 477 EP - 83 JF - The Journal of infectious diseases JO - J Infect Dis VL - 190 IS - 3 N2 - BACKGROUND: Since licensure in the United States, studies have shown that varicella vaccine's overall effectiveness ranges from 44% to 100%, with substantial protection against moderate and severe varicella; however, breakthrough illness has been documented in up to 56% of vaccinated individuals. METHODS: A varicella outbreak occurred in a Minnesota school with 319 students. Phone surveys were conducted with students' parents. Information was collected on students who had recent varicella infections, including onset date, rash characteristics, duration, and underlying medical conditions. RESULTS: Fifty-four cases occurred after a primary breakthrough case. Twenty-nine (53%) students had been vaccinated. Unvaccinated students had an increased risk of moderate varicella, compared with vaccinated students (relative risk [RR], 4.4 [95% confidence interval [CI], 2.2-9.1]; P<.001). The vaccine was 56% effective at preventing any varicella and 90% effective against moderate illness. Students vaccinated >or=5 years before the outbreak had a greater risk of breakthrough varicella than did those vaccinated within <or=4 years (RR, 2.6 [95% CI, 1.3-5.4]; P<.01). CONCLUSIONS: Vaccinated students presented with milder varicella symptoms than did unvaccinated students. Individuals with breakthrough illness can be highly infectious. Time since varicella vaccination was associated with illness. Despite 29 breakthrough cases, the varicella vaccine conferred a high degree of protection against moderate illness. SN - 0022-1899 UR - https://www.unboundmedicine.com/medline/citation/15243919/An_elementary_school_outbreak_of_varicella_attributed_to_vaccine_failure:_policy_implications_ DB - PRIME DP - Unbound Medicine ER -