[Above-average synthesis of anti-HAV by a booster effect after viral hepatitis A (author's transl)].

Above-average high antibody titres without repeat illness were obtained in 31 persons who, after having recovered from viral hepatitis A had renewed contact with the hepatitis-A virus. The titre was five to thirty-fold above the level usually observed after the initial infection. The time of second or third infection appears to be decisive for the level of the titre rise, which is probably a booster effect.