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ABSTRACTUntil recently, periodic Group A meningococcal meningitis outbreaks were a major public health problem in the sub-Saharan Africa. In 2001, the Meningitis Vaccine Project (MVP), a partnership between the World Health Organization (WHO) and PATH, a Seattle-based NGO, and the Serum Institute of India Pvt Ltd (SIIPL) initiated discussions aimed at establishing a collaboration to develop a Group A meningococcal conjugate vaccine for this unmet medical need. Over the next 8 years the partnership made countless strategic decisions about product characteristics, raw materials, potential target populations, geographic prioritization and affordability of the vaccine to name a few. These decisions evolved into detailed plans for preclinical development, extensive field trials in Africa and India and a focused regulatory strategy specific for the Men A conjugate vaccine. Important characteristics of the process included, flexibility, transparency andeffective partnerships that included public agencies as well as private companies in Africa, Europe, the United States and India.

Pre-exposure prophylaxis was given to employees supposed to be involved in rabies vaccine production in India. Prior to availability of the manufacturer’s own human diploid cell (HDC) vaccine (Rabivax®), immunization was executed with a chick embryo cell (CEC) vaccine (Rabipur®). This constellation gave an opportunity to compare retrospectively immunogenicity of these two vaccines. The data was collected by retrospective analysis over more than 3 years at the clinic of Serum Institute of India Ltd. As per the standard protocol, persons with negative rabies vaccination history receive a dose of 1 ml of rabies vaccine intramuscularly on day 0, 7 and 28, and the virus anti-glycoprotein antibodies are measured one month after the third dose. The antibody levels ≥ 0.5 IU/ml are considered protective. The CEC and HDC vaccines were used during the analysis period. In all, 43 individuals received the CEC vaccine, 106 the HDC vaccine. The mean age of recipients was 33 years 5 months (Rabipur®) and 30 years 3 months (Rabivax®). All subjects in both groups were males. Five commercial batches of the CEC vaccine (129 doses) and seven batches of the HDC vaccine (318 doses) were used. 99% of the HDC and 93% of the CEC vaccine recipients were protected after the standard 3 dose schedule. Geometric mean titre was significantly greater for the HDC than CEC vaccine, being 5.05 IU/ml and 2.90 IU/ml, respectively (P=0.0002). The HDC vaccine showed a good lot-to-lot consistency with respect to GMT both by ANOVA test and Nonparametric ANOVA test. On the other hand, the CEC vaccine demonstrated a variation in titres, when the lots were compared. Three out of four low-responders accepted a booster vaccination, and regardless of whether Rabipur® or Rabivax® was used, all three responded well 1 month after the booster. The Indian HDC vaccine compares well with the CEC vaccine in terms of immunogenicity. With HDC vaccines, cost has been an issue. However, since the new HDC vaccine has a comparable cost to the CEC vaccine, it may be possible to use it in large-scale vaccinations.