Indian rotavirus vaccine poses no extra risk of developing intestinal disorder

Four years after its introduction in the national immunization programme, a pan-Indian study has confirmed that a homegrown vaccine against life-threatening rotavirus does not pose any additional risk of a rare but serious intestinal disorder called intussusception.

Carried out in 27 hospitals across India, the study noted that the Indian rotavirus vaccine is not associated with intussusception in infants.

The critics of the Indian rotavirus vaccine in the past had claimed that the homemade product posses higher risks of intussusception - a complication of the intestine in which parts of the intestine slides inside another part another and blocks blood supply.

They claimed that the Indian vaccine is more dangerous than similar vaccines approved by the US Food and Drug Administration.

During the post-marketing surveillance of the vaccine, a team of Indian medical researchers led by Gagandeep Kang from the Christian Medical College, Vellore studied 970 kids with intussusception with 589 others who did not have the disorder between April 2016 and June 2019.

The conclusion of the three-year study – published in the New England Journal of Medicine – is clear and straight forward: there is no increase in intussusception risk among the users of the Indian vaccine (Rotavac) developed by Hyderabad-based Bharat Biotech.

The association of intussusception with rotavirus vaccination was identified in 1998, when RotaShield (made by Wyeth–Lederle Vaccines), the first licensed rotavirus vaccine, was withdrawn because of an increased risk of intussusception.

Subsequent, large, prelicensure trials of the second-generation rotavirus vaccines Rotarix (GlaxoSmithKline Biologicals) and RotaTeq (Merck) did not show an increased risk of intussusception in clinical trials involving 65,000 to 70,000 infants. However, post-marketing surveillance of Rotarix in Australia, Brazil, England, Mexico, and the USA showed one to six excess cases of intussusception per 100,000 vaccinated children.

Post-marketing surveillance of RotaTeq in Australia and the USA too showed one to seven excess cases of intussusception per 100,000 vaccinated children.

Despite the hypothesis that intussusception might be an adverse event associated with all rotavirus vaccines, the World Health Organisation recommended the introduction of rotavirus vaccine into childhood vaccination programmes because the projected incidences of rotavirus infection and deaths due to diarrhea that were averted were greater than the incidence of additional intussusception, resulting in a favorable risk-benefit ratio.