Timing and predictors of severe rotavirus gastroenteritis among unvaccinated infants in low- and middle-income countries

Area of Science:

• Pediatrics
• Infectious Diseases
• Vaccinology

Background:

• Rotavirus vaccine schedules are being considered for modification in low- and middle-income countries (LMICs) to enhance vaccine performance.
• Potential delays in the rotavirus vaccine schedule raise concerns about severe rotavirus gastroenteritis (RVGE) in infants before vaccination.

Purpose of the Study:

• To characterize the timing and identify predictors of severe RVGE in unvaccinated infants within LMICs.
• To inform decisions regarding rotavirus vaccine schedule adjustments in resource-limited settings.

Main Methods:

• Analysis of placebo arms from two distinct clinical trials (NCT00241644 and NCT00362648).
• Estimation of severe RVGE rates, cumulative incidence, and age distribution.
• Utilized Cox proportional hazards models to determine associations between baseline factors and severe RVGE risk.

Main Results:

• Cumulative incidence of severe RVGE by 6 months of age was 23/1000 (cohort 1) and 6/1000 (cohort 2).
• Early antibiotic use was associated with an increased rate of severe RVGE (HR 2.03 in cohort 1, HR 1.41 in cohort 2).
• The incidence of severe RVGE remained low at 6 months across both cohorts.

Conclusions:

• The low cumulative incidence of severe RVGE by 6 months suggests that a potential 4-week delay in rotavirus vaccination is unlikely to lead to a substantial increase in severe disease episodes prior to immunization.
• Findings support the potential feasibility of adjusting rotavirus vaccine schedules in LMICs without significantly increasing the risk of severe RVGE in unvaccinated infants.