Estudio de preformulación de una vacuna pentavalente de DPT-HB-Hib producida en Ecuador

WHO has proposed the development of combined vaccines because of their advantages; in Latin America certain projects were started to this end, although the development of these vaccines is complex due to their technological challenges because of the possible negative interactions between the antigens. The National Institute of Hygiene of Ecuador asked for the collaboration of the CIGB to develop a pentavalent vaccine (DPT-HB-Hib) in Ecuador with diphtherial and tetanus anatoxin, whole cells of Bordetella pertussis (produced in Ecuador), recombinant hepatitis B virus surface antigen and the synthetic polysaccharide (polirribosyl ribitol phosphate, PRP) of Haemophilus influenzae conjugated to tetanus anatoxin (PRP-T) produced at the CIGB. A pre-formulation study was carried out; the adjuvant chosen was aluminum phosphate and the optimum absorption time was of 2h30min for the diphtherial and tetanus anatoxins and the polyribosylribitol phosphate conjugated to the tetanus anatoxin; 3h30min for the surface antigen of the recombinant hepatitis B virus and 18 h for B. pertussis. Two lots were formulated at a pilot scale with the defined technology and the potencies and immunogenicity of the antigens were assessed, as well as their identity and the percentage of adsorption, with satisfactory results. The technology for the formulation of the pentavalent vaccine produced in Ecuador was defined according to these results, which must later undergo stability studies. This is one of the first studies in Latin America related to the development of a pentavalent vaccine containing these antigens.