A new study has revealed that Rotovac, an indigenous rotavirus vaccine by Bharat Biotech, can lead to bowel complications. The findings were published in the International Journal of Risk and Safety in Medicine.

According to the study, the vaccine, which is part of the government’s immunization program, has been associated with an increased risk of intussusception in infants. Intussusception is a serious condition where one part of the intestine slides into the next, potentially leading to bowel gangrene or even death without immediate treatment.

The study, co-authored by Jacob Puliyel, MD of the International Institute of Health Management Research, India, and Brian Hooker of Children’s Health Defense, revealed a 1.6-fold increased risk of intussusception among vaccinated infants, which was not previously detected in initial analyses. According to a report by ET, Puliyel emphasized the need for parents to be informed about this risk due to the vaccine’s potential to mimic dysentery symptoms.

Meanwhile, Bharat Biotech dismissed the study, stating that the vaccine’s safety had been rigorously evaluated. The company referred to previous analyses, including one from the New England Journal of Medicine in 2020, which suggested no increased risk of intussusception beyond the background level in vaccinated infants. Bharat Biotech reaffirmed Rotovac’s safety, emphasizing its manufacture from human rotavirus strains and not animal origins. The drugmaker also criticized the recent study’s methodology, asserting it deviated from established statistical plans, thus questioning its validity.

In 2020, a New England Journal of Medicine analysis found there was no risk of intussusception from Rotovac, a live attenuated rotavirus vaccine. A statistical method called self-controlled case series (SCCS) determined that the risk of intussusception in the high-risk window (21 days after any dose of the vaccine) was comparable to the background risk. The company stated that the data is not new but a reanalysis of old data that was “out of line with the experimental design and statistical plan. Hence, it cannot be interpreted in a meaningful manner to merit serious consideration.”

“Rotovac is manufactured using human rotavirus strains and not from animal origin. Hence, the rate of intussusception is similar in vaccinated and non-vaccinated subjects,” the company said in a statement.