Bar-Zeev N, et al. - In this population-based cohort study, researchers examined the impact and effectiveness of the rotavirus vaccine (RV1) vaccine in decreasing diarrhoea-associated mortality in infants aged 10 to 51 weeks. Among infants in this rural sub-Saharan African setting, RV1 was related to substantial reduction in diarrhoea-associated deaths. The results obtained from the study add considerable weight to evidence exhibiting the impact of rotavirus vaccine programmes.

Methods

• Study participants were infants born between Jan 1, 2012, and June 1, 2015, in Mchinji, Central Malawi and analysed data on those surviving 10 weeks.
• Researchers extracted individual vaccination status from caregiver-held records or report at home visits at 4 months and 1 year of age.
• Survival to 1 year was confirmed at home visit.
• Cause of death ascertained by verbal autopsy.
• Using Poisson regression, they evaluated impact (1 minus mortality rate ratio following vs before vaccine introduction).
• They evaluated effectiveness (1 minus hazard ratio) using Cox regression among vaccine-eligible infants (born from Sept 17, 2012).

Results

• Forty-eight thousand, six hundred seventy-two livebirths were enlisted in Mchinji, among whom 38,518 were vaccine-eligible and 37,570 survived to age 10 weeks between Jan 1, 2012, and June 1, 2015.
• Two-dose vs zero-dose effectiveness analysis involved 28,141 infants, of whom 101 had diarrhoea-associated death before 1 year of age.
• It was observed that diarrhoea-associated mortality declined by 31% (95% CI 1–52; p=0.04) after RV1 introduction.
• They found that effectiveness against diarrhoea-mortality was 34% (95% CI –28 to 66; p=0.22).