Related Experiment Videos
Inactivated hepatitis A vaccine: long-term antibody persistence
G Wiedermann1, M Kundi, F Ambrosch
1Institute of Specific Prophylaxis and Tropical Medicine, University of Vienna, Austria.
Vaccine
|April 1, 1997
Summary
Long-term studies show inactivated hepatitis A vaccines induce protective antibodies that persist for decades. Antibody levels decrease slowly after the first year, with estimated persistence ranging from 24 to 47 years based on dose and individual response.
Area of Science:
- Virology
- Immunology
- Vaccinology
Background:
- Previous hepatitis A vaccine studies had limited long-term antibody persistence data (18 months to 3 years).
- Understanding long-term antibody persistence is crucial for evaluating vaccine efficacy and duration of protection.
Purpose of the Study:
- To assess the long-term persistence of antibodies following vaccination with an inactivated hepatitis A vaccine candidate.
- To determine the duration of protective antibody levels in adults vaccinated in early clinical trials.
Main Methods:
- A randomized trial involving 110 hepatitis A virus (HAV) seronegative adults vaccinated with inactivated HAV vaccine (180, 360, or 720 ELISA units).
- Blood samples were collected serially for 84 months post-vaccination.
- Antibody disappearance rates were modeled using a two-component model.
Main Results:
- Antibody levels exhibited a biphasic decline: a rapid early phase followed by a slower, predominant phase after 12 months.
- The slow component's annual antibody decrease was 11% and 13% for the 180 and 360 ELISA units groups, respectively.
- Estimated antibody persistence within protective levels ranged from 24 to 47 years, influenced by vaccination dose and initial antibody titers.
Conclusions:
- Inactivated hepatitis A vaccines demonstrate excellent long-term antibody persistence.
- Antibody levels are predicted to remain protective for over two decades, supporting the vaccine's long-term immunogenicity.
- Vaccination dose and individual immune response significantly impact the duration of antibody persistence.