A recent study published in The International Journal of Risk and Safety in Medicine has raised significant safety concerns about Rotavac, the rotavirus vaccine that is included in the government’s immunisation program and is widely used in India. The study found that Rotavac increases the risk of intussusception, a serious condition where the intestine folds into itself, potentially leading to bowel gangrene or death if not treated promptly.
The study was co-authored by Dr Jacob Puliyel of the International Institute of Health Management Research, India and Dr Brian Hooker, Chief Scientific Officer at Children’s Health Defence. Their research challenges a 2020 analysis by the New England Journal of Medicine, which found no risk of intussusception associated with Rotavac. The earlier study used a statistical method called self-controlled case series (SCCS) and concluded that the risk within 21 days after vaccination was comparable to the background risk.
Dr Puliyel and Dr Hooker re-evaluated the same raw surveillance data using a different method known as self-controlled risk interval (SCRI). Their analysis revealed a 1.6-fold increase in the risk of intussusception in vaccinated infants, a risk that was not detected in the earlier SCCS analysis. They also noted that vaccinated babies developed intussusception at a younger age, heightening the risk of severe outcomes, including death.
Furthermore, the authors conducted a time-to-intussusception analysis from the last vaccination which showed the highest number of intussusception cases occurred within a month after vaccination, with the risk decreasing over time. Specifically, 93 cases were reported in the first 30 days, compared to the following 30 days. This finding was statistically significant and supported the SCRI analysis.
Dr Hooker highlighted the difficulty parents might face in recognising intussusception, as its initial symptom—passage of blood and mucus in the stools - can easily be mistaken for infectious dysentery. “Intussusception often requires surgery to prevent death, so parents need to be informed and vigilant,” he said.
The SCCS method, according to the study, fails when the overall age of onset for intussusception is altered by vaccination. The authors assert that the original SCCS analysis missed this risk and call for re-evaluation of all previous SCCS studies.
Dr Puliyel stressed the importance of raising awareness about the symptoms of intussusception among parents and caregivers, especially in remote rural areas where the vaccine is administered as apart of the national immunisation programme. “Every parent must know the symptoms of intussusception so that children impacted can receive emergency medical intervention,” he said.
While acknowledging that post-marketing surveillance can indicate increased risk, Dr Puliyel noted that without data from unvaccinated controls, the magnitude of the risk remains difficult to estimate. He urged for the publication of data from the original randomised control (RCT) conducted in India to provide clearer insights.
Rotavac is a live attenuated rotavirus vaccine that has been developed by Bharat Biotech. Currently, there are two other live oral vaccines that are licensed and marketed in India for rotavirus. They include GlaxoSmithKline’s (GSK) Rotarix and Merck & Co., Inc. manufactured Rotateq.
