Intussusception after Rotavirus Vaccine Introduction in India

BACKGROUND: Rotavac®, an Indian-made, 3-dose, oral rotavirus vaccine, was introduced in the universal immunization program in India in 2016. Pre-licensure safety data for the vaccine were limited to a single trial of 6800 Indian infants; here we report results of a post-marketing surveillance study to assess a level of intussusception risk similar to that seen with other multinational rotavirus vaccines in other countries. METHODS: Multicentric hospital-based active surveillance was conducted at 27 Indian hospitals from April 2016 to June 2019. Children meeting Brighton level 1 criteria of radiological or surgical confirmation of intussusception were enrolled and vaccination was ascertained through vaccination records. The relative incidence (RI) for intussusception within 1-7, 8-21 and 1-21-days post-vaccination in children 28-365 days of age was evaluated by self-controlled case-series (SCCS) analysis. For a subset, a matched case-control analysis was performed with age-, gender- and location-matched controls. RESULTS: 970 cases were enrolled, and 589 children 28-365 days of age were included in the SCCS analysis. Post-dose 1, intussusception relative incidence (RI) was 0.83 (95% CI 0.0, 3.00) and 0.35 (95% CI 0.0, 1.09) in the 1-7 and 8-21 day windows, respectively. Similar results were observed post-dose 2 (RI=0.86 (95% CI 0.20, 2.15) and 1.23 (95% CI 0.60, 2.10), respectively), and post-dose 3 (RI=1.65 (95% CI 0.82, 2.64) and 1.08 (95% CI 0.69, 1.73), respectively). No increase in intussusception risk was found in the case-control analysis. CONCLUSION: The rotavirus vaccine produced in India and evaluated here was not associated with intussusception in Indian infants.