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Published on: May 6, 2015
Randomized, cross-over, controlled comparison of two inactivated hepatitis A vaccines
J P Bryan1, C H Henry, A G Hoffman
1Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814-4799, USA. jbryan@usuhs.mil
Vaccine
|December 15, 2000
Summary
This study compared two hepatitis A vaccines, Vaqta and Havrix. Both vaccines showed similar seroconversion rates, but Vaqta produced higher antibody levels, especially as a booster dose.
Area of Science:
- Immunology
- Vaccinology
- Hepatology
Background:
- Hepatitis A virus (HAV) infection is a global health concern.
- Effective vaccination is crucial for preventing HAV transmission.
- Understanding the comparative immunogenicity of available vaccines is important for public health strategies.
Purpose of the Study:
- To compare the immunogenicity, tolerability, and interchangeability of Vaqta and Havrix hepatitis A vaccines.
- To evaluate antibody responses and seroconversion rates following different vaccination regimens.
- To assess the safety profile of both vaccines in a randomized, crossover trial.
Main Methods:
- A randomized, crossover, controlled clinical trial involving 201 volunteers.
- Administration of Vaqta and Havrix vaccines at 0 and 26 weeks in four different regimens.
- Measurement of seroconversion rates and geometric mean concentrations (GMC) of antibodies to HAV (anti-HAV).
- Monitoring of adverse events, including local reactions like tenderness and pain.
Main Results:
- Seroconversion rates were similar for both vaccines at 2, 4, and 26 weeks.
- Vaqta demonstrated significantly higher GMC of anti-HAV compared to Havrix at 4, 26, and 30 weeks.
- Crossover immunization was well tolerated, with less than half of recipients reporting mild local reactions.
- The Vaqta booster dose resulted in particularly high antibody concentrations.
Conclusions:
- Both Vaqta and Havrix are effective hepatitis A vaccines with similar seroconversion rates.
- Vaqta elicits a significantly higher antibody response than Havrix.
- Crossover vaccination strategies are safe and effective, with Vaqta as a booster potentially offering enhanced antibody levels.
- The long-term clinical significance of higher anti-HAV antibody concentrations requires further investigation.
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