In Phase III trial, Serum Institute’s rotavirus vaccine (ROTASIIL) was found to have nearly 55% efficacy against the very severe form of rotavirus diarrhoea and nearly 39% efficacy in severe rotavirus cases.

A rotavirus vaccine tested on children during a Phase III trial for efficacy has been found to be safe and efficacious. The vaccine (ROTASIIL) manufactured by the Pune-based Serum Institute of India has nearly 39% efficacy in children with severe rotavirus cases and nearly 55% against the very severe form of rotavirus diarrhoea. The vaccine targets all the five rotavirus serotypes.

In 2013, an estimated 47,000 rotavirus deaths occurred in India. India accounted for 22% of all rotavirus deaths in the world.

The Phase III trial was carried out at six sites in India. Three doses of the vaccine were given at 6, 10, and 14 weeks of age to 3,749 infants, while another group of 3,751 children was given a dummy. Children were randomly assigned to receive either the vaccine or the dummy and neither the children and their parents nor those involved in vaccinating the children was aware who was receiving the vaccine and who was receiving the dummy.  The vaccinated children were followed-up till they turned two years old to study the safety of the vaccine. The results were published on September 26 in the journal Vaccine.

The three doses of the vaccine were given at 6, 10, and 14 weeks to coincide with the routine vaccination under India’s Universal Immunization Programme.

The vaccine used is a mixture (reassortment) of bovine and human rotavirus. “We took five numbers of the single bovine rotavirus serotype and added one gene from each of the five human rotavirus serotypes to the bovine serotype. The bovine serotype acted as a backbone while the gene from the human rotavirus conferred protection. The bovine serotype does not cause diarrhoea in children. But as the bovine serotype carried the human antigen (gene) it helps the human body to develop antibodies against all the five human rotavirus serotypes,” says Dr. Prasad S. Kulkarni, Medical Director at Serum Institute, Pune.

Bharat Biotech launched a human rotavirus vaccine in 2015. Unlike the Serum vaccine, the one introduced by Bharat Biotech contains only one serotype. Even the rotavirus from GSK is a monovalent vaccine, while Merck’s vaccine contains all the five human rotavirus serotypes.

The international NGO PATH partnered with Serum Institute on evaluating the vaccine in the Phase III trial.

Published in The Hindu on September 27, 2017