Efficacy of rotavirus vaccine in primary care

Abstract

Aim: To determine the coverage of anti-rotavirus immunization in the Family Health Unit of S. João do Porto and to test the association of immunization with clinical outcomes (number of episodes of acute gastroenteritis, their duration, and days of work lost by the parents). Type of study: Cross-sectional Setting: Family Health Unit S. João do Porto Population: Children aged between 6 months and 5 years old Methods: Parents of 500 children, randomly selected from the list of patients of the Health Unit, were contacted by telephone for this survey. The chi-square test, Mann-Whitney U test, and Mantel-Cox test were used for univariate analysis of the association between the predictor and outcome variables. Multivariate analysis was performed using a logistic regression model. Significance was set at the of 0.05 level. Results: Immunization coverage by rotavirus vaccine in this population was 55.1% (95%CI: 48.8-61.4%). Entry into kindergarten before 6 months of age was associated with higher vaccination coverage (p=0.015). The median age for entry to kindergarten was lower in the vaccinated group (11 vs 24 months, p=0.007). After adjusting for gender, age, low birth weight, prematurity, comorbidity, breastfeeding for over 3 months, and attending kindergarten before 6 months of age, the odds ratio for the efficacy of the vaccine was estimated to be 0.933 (95%CI: 0.539-1.613). Conclusions: Over half of this population received rotavirus immunization. This study did not find evidence of clinical efficacy of the vaccine, neither in terms of number of episodes of diarrhea, their duration, nor in work days lost by caregivers. These findings raise questions about the value of rotavirus vaccine.