[Effectiveness of VA-MENGOC-BC in children from 0 to 5 years of age in Cuba. First year of observation].

The effectiveness or post-license efficacy of the BC antimeningococcal vaccine (VA-MENGOC-BC) was assessed 1 year after the end of the immunization campaign in children aged 0 to 5 years. Occurrence of the disease before and after intervention is described and effectiveness is estimated following the recommendations described by Orenstein et al. We used 2 case definitions to compare results in groups formed following different criteria, according to the employed diagnostic tests. Two formulas are used to assess efficacy: one, estimating the rates among vaccinated and non-vaccinated; and the other one, estimating the ratio of cases per vaccinated population. The increase of the relative annual decrease of the incidence occurring since 1985--a decrease of 10% or less--which in 1990 reached 34.6% should be stressed; the ratio of new cases prevented by the intervention was higher than 75%. Effectiveness or post-license efficacy was close to 90%, independently from the case definition variant or formula employed.