DRL to submit more data on Sputnik by July

Colour-coded doses will have two different antigens

The Russian vaccine Sputnik V, named after the Soviet era satellite Sputnik, got the nod from India’s Covid-19 vaccine expert panel on Monday. However, more data has been sought from its Indian partner Dr Reddy’s Laboratories (DRL) by the expert panel, which is expected by July.

“The firm presented the data from only 72 Russian volunteers and around 275 or so Indian volunteers. We have sought more data from it. DRL has promised to come back with this data by July or so,” said an expert on the panel.

The person added that there were no safety-related concerns about the vaccine candidate and it has also shown an efficacy of over 91 per cent.

“There were no cases of any serious adverse events. Fever was the most common side-effect cured easily with paracetamol. However, we wanted to have comparative immunogenicity data between the Russian and Indian volunteers and more details on the neutralising antibody titers,” said the source.

Sputnik V is a heterogenous vaccine, using two different virus strains or antigens in its two doses. The first dose uses human adenovirus (a common flu virus) type 26 (Ad26), which is the same as that used by Johnson & Johnson (J&J) in its single shot vaccine.

J&J vaccine has 85 per cent efficacy against severe disease after 28 days. DRL and Russian sovereign wealth fund Russian Direct Investment Fund (RDIF) have claimed that Sputnik V would show efficacy from Day 28 and peak by Day 42.

The second shot of the vaccine will use adenovirus type 5 (Ad5). In order to differentiate between the two doses — primer and booster — the colours of the vaccine will be different. The colours will be distinct to avoid confusion among vaccinators.

By deploying two different vectors, Sputnik V avoids a possible neutralising effect and generates a durable and longer-lasting immune response, claimed RDIF.

DRL has indicated it would provide the cold chain solution for Sputnik V. It requires minus 18 degrees Celsius to remain stable. Details of the cold chain plan, however, were not provided, claimed sources.

Earlier RDIF had noted: “Due to the time needed for the immune response to develop, in the first week after vaccination there was no significant difference in protection against severe cases of Covid-19 between the vaccine and the placebo groups. In the period from 7 to 14 days, the vaccine’s efficacy rose to 50 per cent. In the period from 14 to 21 days to 74.1 per cent, and to 100 per cent from Day 21, giving full protection against severe cases of the coronavirus.”

“RDIF confirms it is awaiting the recommendation by the subject expert committee of the Central Drugs Standard Control Organisation to approve the use of the Sputnik V in India,” a spokesperson for RDIF said on Monday.