VAQTA demonstrated 100% efficacy against hepatitis A in the landmark Monroe study of 2 to 16-year-olds
A landmark study was done to evaluate the efficacy of VAQTA in children 2 to 16 years of age, along with a 9-year follow-up study.1,2,a
In the Monroe study, VAQTA demonstrated 100% efficacy against hepatitis A with 21 cases occurring in the placebo group and none in the vaccine group (P < 0.001) ≥ 50 days after vaccination.1
Following review of the interim analysis of the initial study after a single dose, the monitoring committee recommended that the study be terminated so that the placebo recipients could be vaccinated. A booster dose was administered to a subset of vaccinees 6, 12, or 18 months after the primary dose.1
Clinical study designs
aAn initial randomized, double-blind, placebo-controlled study was conducted to evaluate the efficacy of a single dose of VAQTA in a community with recurrent outbreaks. In this study, 1037 children, 2 to 16 years of age, were enrolled. Each child received an intramuscular dose of VAQTA (25 U) (n=519) or placebo (n=518). Efficacy was based on clinically confirmed cases of hepatitis A occurring ≥ 50 days after vaccination.1
After 5 months, the initial study was terminated so that the vaccine could be provided to the subjects in the placebo group. A second (booster) dose was administered at 6, 12, or 18 months after the first dose of VAQTA. All vaccinees were closely monitored for clinically confirmed cases of hepatitis A from 1991 to January 2001.1,2
The total duration of the protective effect of VAQTA in healthy vaccinees is unknown at present.
Vaccination with VAQTA may not result in a protective response in all susceptible vaccinees.
There are many opportunities to vaccinate your pediatric patients3
References
- Werzberger A, Mensch B, Kuter B, et al. A controlled trial of a formalin-inactivated hepatitis A vaccine in healthy children. N Engl J Med. 1992;327(7):453–457.
- Werzberger A, Mensch B, Nalin DR, et al. Effectiveness of hepatitis A vaccine in a former frequently affected community: 9 years’ followup after the Monroe field trial of VAQTA. Vaccine. 2002;20(13–14):1699–1701.
- Advisory Committee on Immunization Practices (ACIP). Recommended child and adolescent immunization schedule for ages 18 years or younger, United States, 2024. Accessed June 25, 2024. https://www.cdc.gov/vaccines/schedules/downloads/child/0-18yrs-child-combined-schedule.pdf