title: [Efficacy and safety of a vaccine against human leptospirosis in Cuba].
abstract: OBJECTIVE
  To evaluate the efficacy of vax-SPIRAL, a Cuban vaccine against leptospirosis, and to provide additional information concerning the safety of this vaccine (which was developed by Cuba's Finlay Institute).
  
  
  METHODS
  This phase III efficacy trial of vax-SPIRAL was controlled, randomized, and double blind. The control vaccine used for the trial was Heberbiovac-HB (Heber Biotec, Cuba), a recombinant hepatitis B vaccine. The randomization unit for allocating persons to the study group or the control group were 523 family physician offices in the selected municipalities. The study covered the entire population of males and females from 20 to 64 years old who voluntarily agreed to participate, from the municipalities of Ranchuelo, Quemado, Santo Domingo, Encrucijada, Corralillo, Cifuentes, and Camajuaní, which are in the province of Villa Clara, in the central region of Cuba. The vaccinations were given in the physicians' offices between February and July 1998, with an interval of 6 weeks between the two doses. The follow-up period was 12 months. A case was considered positive if a person who had received the two doses of the vaccine became ill with leptospirosis more than 21 days after receiving the second dose, with the diagnosis confirmed through serological and microbiological methods. We calculated the efficacy of the vaccine and the relative risk of becoming ill with leptospirosis after the vaccination. For the safety study, two persons were chosen at random from among the individuals vaccinated at the office of each physician participating in the study. Follow-up of local and systemic adverse reactions was carried out by the family physicians during the seven days after the application of each dose. The level of statistical significance was set at 0.05.
  
  
  RESULTS
  A total of 101 832 persons were vaccinated, with 50 354 of them (49.4%) receiving the leptospirosis vaccine and 51 478 of them (50.6%) receiving the control vaccine. The efficacy of the vax-SPIRAL vaccine was 78.1% (95% confidence interval (CI): 59.2% to 88.3%), and the relative risk of becoming ill with leptospirosis after receiving the leptospirosis vaccine was 0.22 (95% CI: 0.12 to 0.41). General discomfort was the most frequent systemic adverse reaction, and mild spontaneous pain at the injection site was the most frequent local effect. The local and systemic adverse reactions were both more frequent in the study group than in the control group (P = 0.003). There were no serious adverse events.
  
  
  CONCLUSIONS
  The vax-SPIRAL vaccine proved to be safe and efficacious for leptospirosis control. The vaccine is recommended for use in preventing this disease among groups at risk of contracting it.
authors.affiliation: Instituto de Medicina Tropical Pedro Kourí, Ciudad de La Habana, Cuba. raydel@ipk.sld.cu
authors.forename: Raydel
authors.initials: R
authors.lastname: Martínez
authors.forename: Alberto
authors.initials: A
authors.lastname: Pérez
authors.forename: María del C
authors.initials: Mdel C
authors.lastname: Quiñones
authors.forename: Raúl
authors.initials: R
authors.lastname: Cruz
authors.forename: Angel
authors.initials: A
authors.lastname: Alvarez
authors.forename: Marlén
authors.initials: M
authors.lastname: Armesto
authors.forename: Carmen
authors.initials: C
authors.lastname: Fernández
authors.forename: Jorge
authors.initials: J
authors.lastname: Menéndez
authors.forename: Islay
authors.initials: I
authors.lastname: Rodríguez
authors.forename: Morelia
authors.initials: M
authors.lastname: Baró
authors.forename: Manuel
authors.initials: M
authors.lastname: Díaz
authors.forename: José
authors.initials: J
authors.lastname: Rodríguez
authors.forename: Gustavo
authors.initials: G
authors.lastname: Sierra
authors.forename: Ana Margarita
authors.initials: AM
authors.lastname: Obregón
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Toledo
authors.forename: Norma
authors.initials: N
authors.lastname: Fernández
mesh_terms: D000328:Adult; D001428:Bacterial Vaccines / Q000009:adverse effects; D003462:Cuba; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007919:Leptospira / Q000276:immunology*; D007922:Leptospirosis / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged
chemical_list: D001428:Bacterial Vaccines