Immunogenicity of an inactivated hepatitis A vaccine after exposure at 37 degrees C for 1 week

The reactogenicity and immunogenicity of a recently released lot of inactivated hepatitis A vaccine (Havrix) were compared after storage at 37 degrees C for 1 week and at the recommended storage temperature of 2-8 degrees C, in two groups of healthy adults in a randomized, double-blind controlled study. The reactogenicity, geometric mean concentrations and seroconversion rates were all similar in both groups, confirming the good thermal stability of the vaccine.