[Serological response by ELISA and MAT in Cuban volunteers vaccinated with vax SPIRAL]

The seroconversion of 408 vaccinated individuals and 135 placebo included in 2 clinical trials of the Cuban vaccine against human leptospirosis was studied. 2 vaccine doses and 5 schemes were studied. Of 38 vaccinated subjects (Phase I), 11 (29 %) seroconverted by MAT and 12 (32 %) by ELISA, whereas in 33 placebo, seroconversion was observed in 2 (6 %) and 3 (9 %), respectively. In Phase II, of 68 vaccinated individuals (doses of 0.25 mL) and of 65 (doses of 0.50 mL), seroconversion was attained in 21 (31 %) and 16 (25 %) by ELISA, respectively, 9 by MAT (13 %) and 7 (11 %) were positive. There were no significant differences between the doses used. The seroconversion by MAT in 237 subjects vaccinated with different schemes was 22.4 %. No marked differences were observed between them. In most of the reactive individuals, antibody levels were found in at least one of the vaccine strains. It was recommended to search and evaluate other methods to show in vivo the level of protection of this vaccine.