The 130th Annual Meeting of APHA

4124.0: Tuesday, November 12, 2002 - 12:45 PM

Abstract #47517

Breakthrough Varicella Infection in West Philadelphia

Dana Perella, BS1, Barbara Watson, MD2, Karl Heath, RN, GCP3, Donovan Robinson, MPH3, Robert Levenson, MBA1, James Lutz, MPA2, Jane Seward, MBBS, MPH4, Aisha Jumaan, PhD, MPH4, and Karin Gahill, MD, MPH4. (1) Division of Disease Control, Philadelphia Department of Public Health, 500 S. Broad St., 2nd Flr., Philadelphia, PA 19146, 215-685-6498, dana.perella@phila.gov, (2) Divison of Disease Control, Philadelphia Department of Public Health, 500 S. Broad Street, Philadelphia, PA 19146, (3) Immunization Program, Philadelphia Department of Public Health, 500 S. Broad, Philadelphia, PA 19146, (4) National Immunization Program, Centers for Disease Control and Prevention, 1600 Clifton Rd., Atlanta, GA 30333

Background: Through active varicella surveillance, the Philadelphia Department of Public Health (PDPH) in collaboration with CDC has been able to document the occurrence and epidemiology of varicella in the inner-city area of West Philadelphia since varicella vaccine licensure in 1995. When vaccine-derived immunity predominates, it is projected most varicella cases will be breakthrough infections or varicella-like rashes occurring in previously vaccinated individuals more than 42 days after vaccination.

Objective: To describe characteristics of individuals who develop breakthrough varicella infection.

Methods: Clinical and epidemiologic data were collected during the investigation of varicella cases in the West Philadelphia surveillance area from 1995 to 2001. Breakthrough cases were defined as confirmed varicella cases, who received the vaccine on or after their first birthday and had rash onsets greater than 42 days from receipt of vaccine.

Results: 211 breakthrough varicella cases were reported from 1995 through preliminary year 2001data. Breakthrough cases comprised 0.1%, 0.9%, 2.8%, 6.8%, 16.2%, 26.8% and 37.2% of the varicella cases for years 1995, 1996, 1997, 1998, 1999, 2000 and 2001, respectively. Time from vaccination to rash onset ranged from 46 to 2121 days. Median age at time of vaccination for the breakthrough cases was 22 months, while median age at rash onset was 4 years. Most breakthrough cases were Non-Hispanic African Americans (82.0%), and slightly more cases were male than female. Disease presentation tended to be mild with no complications.

Conclusions: As vaccine coverage levels increase, it is important to examine factors potentially associated with the development of breakthrough varicella.

Learning Objectives:

Keywords: Epidemiology, Immunizations

Presenting author's disclosure statement:
Organization/institution whose products or services will be discussed: Merck VARIVAX Varicella Vaccine
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.

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The 130th Annual Meeting of APHA