In a major validation of India’s vaccine innovation capabilities, a landmark nationwide study found that Bharat Biotech’s ROTAVAC has reduced severe rotavirus-related diarrhoea hospitalisations in children by nearly 50%, reinforcing the vaccine’s transformative public health impact under India’s Universal Immunisation Programme (UIP). 

Published in Nature Medicine, the multi-centre study tracked 24,624 children across 31 hospitals in nine states between 2016 and 2020 and reported a 54% real-world effectiveness against severe rotavirus gastroenteritis—almost identical to the 54% efficacy seen in Phase III trials. 

These findings provide the most definitive real-world proof of ROTAVAC’s effectiveness in India’s public immunisation ecosystem, underscoring how indigenous science can deliver large-scale disease reduction.

The study found that the proportion of diarrhoea-related hospitalisations caused by rotavirus fell from 40% before vaccine rollout to 20% after introduction, effectively halving the disease burden on paediatric wards. 

Before ROTAVAC’s rollout in 2016, rotavirus accounted to nearly one in every three paediatric diarrhoea hospital admissions in India, a country that historically contributed around one-fifth of global rotavirus deaths. 

The data now points to a clear nationwide decline in severe childhood diarrhoeal disease, especially in the most vulnerable under-five age group.

Strong cross-protection against global strains

One of the most significant findings is the vaccine’s robust cross-protection beyond its original strain design.

Although ROTAVAC is based on a single indigenous neonatal strain G9P[11], the study demonstrated strong protection against widely circulating global variants including G1P[8] and G3P[8], confirming its resilience in real-world settings where viral strains evolve constantly. This broad genotype protection significantly strengthens ROTAVAC’s relevance not only for India but also for other high-burden emerging markets.

Researchers also observed a notable herd effect, with declining infection rates seen even in children outside the directly eligible vaccination age group. This suggests that wider infant immunisation is reducing community-level transmission, extending indirect protection to older children and helping break the rotavirus transmission cycle. 

A major win for affordable vaccines from the Global South

Dr. Krishna Ella, Executive Chairman of Bharat Biotech, commended the findings as a significant milestone for Indian science and innovation. He stated, “This study reaffirms that science developed with purpose can deliver lasting public health impact. The strong real-world performance of the vaccine, including protection against diverse rotavirus strains, demonstrates its resilience and relevance in high-burden settings. It strengthens our commitment to advancing solutions that protect the most vulnerable children.” 

Importantly, Bharat Biotech’s ROTAVAC® vaccine delivers results specifically designed to be affordable for the Global South. The WHO Prequalification facilitates extensive rollout and the supply of ROTAVAC® vaccine to countries across Asia, Africa, Latin America, and the Middle East, reaching populations who need it the most. By ensuring equitable access, the vaccine can substantially improve the high rotaviral mortality rates in children under 5 years, particularly in high-burden regions where rotavirus diarrhoea remains a leading cause of childhood fatalities. 

For a disease that once overwhelmed paediatric wards, these findings signal a new era: severe rotavirus disease and mortality is no longer an inevitable part of childhood in India. 

Source Study:
Impact of the indigenous rotavirus vaccine Rotavac in the Universal Immunization Program in India during 2016–2020. Nature Medicine (2025).