Preventing rabies with the Verorab vaccine: 1985-2005 Twenty years of clinical experience

Purified rabies vaccine cultured on Vero cells (Verorab, sanofi pasteur) is WHO-approved for pre- and post-exposure prophylaxis by intradermal and intramuscular routes. During 20 years of use, over 40 million doses of Verorab have been administered in more than 100 countries. No serious adverse event due to Verorab has been reported in clinical trials involving 3937 persons, and Verorab is better tolerated than human diploid cell vaccine (HDCV). Pre-exposure prophylaxis is confirmed immunogenic in 1437 subjects by all routes, with prompt responses following boosting; Verorab boosts effectively subjects pre-immunized with HDCV. Unlike HDCV, Verorab is not associated with post-boosting serum sickness. In the absence of data in immunodeficient/HIV-positive individuals, pre-exposure immunization is urged as early as possible. Essen, Zagreb, Thai Red Cross Intradermal (TRC-ID) and other post-exposure intramuscular and intradermal regimens are documented. Two thousand one hundred and eighty-three subjects received post-exposure prophylaxis, including 874 high risk, severe or confirmed rabid attacks. Co-administration of rabies immune globulin (RIG) does not affect neutralizing antibody levels when Essen or TRC-ID regimens are employed; levels are lower with the Zagreb regimen. Verorab has been administered safely and effectively post-exposure to 251 pregnant women, without any increase in congenital malformations or spontaneous abortions. From a pediatric perspective, safety and efficacy have been demonstrated in 759 children (0-15 years). Intradermal post-exposure Verorab is an effective and inexpensive option for developing countries. Inadvertent subcutaneous administration does not reduce immunogenicity. WHO already strongly recommends the replacement of nerve tissue vaccines with modern vaccines. Extensive clinical experience supports the use of Verorab for intramuscular and intradermal pre- and post-exposure prophylaxis, including in special situations.