Oral rotavirus vaccine effectiveness among malnourished children in 19 countries: Findings from the MNSSTER-V project.

OBJECTIVES

Rotavirus vaccine clinical trials and post-licensure evaluations found malnourished children may have lower protection against rotavirus diarrhea hospitalizations than well-nourished children. On a population level, rotavirus vaccines are less protective in high child mortality settings.

METHODS

We analyzed rotavirus vaccine effectiveness (VE) among malnourished and well-nourished children categorized using four anthropometric malnutrition indicators, birthweight, and reported malnutrition from medium to high child mortality countries in the Multi-National Subpopulations Study to Evaluate Rotavirus Vaccines (MNSSTER-V) dataset. We calculated child-level z-scores for weight-for-age, length-for-age, weight-for-length, and mid-upper arm circumference (MUAC), and the site-level proportion implausible z-scores. Sites with published VE estimates by nutritional status or those with <3% implausible values were included in the final analysis. Z-scores <-2 were considered moderate-to-severe malnutrition and <-3 were considered severe malnutrition. We calculated complete series rotavirus VE in each malnourished and well-nourished group using an unconditional adjusted logistic regression model, where VE = (1 - odds ratio of vaccination among cases and controls) × 100, where cases and controls were children who tested rotavirus positive and negative, respectively.

RESULTS

Complete series VE was more protective among children without stunting (normal length-for-age) (59%; 95% confidence interval [CI]: 49-67) compared to children with moderate-to-severe stunting (42%; 95% CI: 19-58) and severe stunting (31%; 95%CI: -14 to 58). Adjusted VE point estimates were similar among malnourished and well-nourished children using the other anthropometric and birthweight indicators.

CONCLUSIONS

Our findings clearly show that chronic malnutrition negatively impacted rotavirus VE. Efforts to address and prevent malnutrition generally may further reduce the burden of rotavirus morbidity and mortality.