Cuban Medical Literature: Abstracts Vax-TyVi: Salmonella typhi Vi Polysaccharide Cuban Vaccine*

The vaccine of whole cells inactivated by heat and phenol that has been used in Cuba since 1983 is highly reactogenic and has shown little epidemiological impact. A technology was developed to substitute this vaccine for a Vi Polysaccharide of new generation, competitive with those existing in the international market. The technology developed is characterized by a new medium that maximizes the yield of polysaccharide and its purification method, which form part of the practical knowledge of the proposed technology. The process at laboratory scale was characterized as well as the quality of the Vi Polysaccharide obtained and it was developed to production scale. The Vi Polysaccharide obtained at production scale as well as the final vaccine were studied both at the Finlay Institute and in collaboration with the National Institute for Biological Standards and Control of Great Britain, where it was demonstrated that it was similar to the reference. For the quantification of the Vi Polysaccharide it was set up, standardized and validated an inhibition ELISA system, not reported for these purposes. A new generation vaccine was obtained adequate for its use in Cuba and its commercialization and the bases were set for a new generation of antidiarrheic combined vaccines. The product was assayed in a homologation clinical study and it did not show differences with the one of the Aventis Pasteur company. With these results, the approval was obtained from the Sanitary Medical Register. A total of 900,000 doses have been produced which are being distributed throughout the national vaccination network.