Gap Between Sputnik V COVID-19 Shots Can Be Up to 180 Days: Russia's RDIF

By Reuters Staff

July 12, 2021

MOSCOW (Reuters) - The gap between the two shots of the Sputnik V coronavirus vaccine can be extended up to 180 days and it will remain effective, the Russian Direct Investment Fund (RDIF) said on Friday.

An official at the RDIF, which markets the vaccine abroad, made the comments in a statement after some countries decided to widen the gap between the first and second doses of the vaccine developed in Russia.

Kazakhstan has said a longer interval between shots provides a stronger immune response. Argentina has increased the gap to prioritise ensuring that as many people as possible receive at least a single dose.

Alexander Gintsburg, director of the Gamaleya Institute which developed the vaccine, said in April that the gap between the shots could be increased to 90 days.

The RDIF official quoted Gamaleya trials as showing longer gaps had secured a better immune response, but provided no further details of the trials. The official issued the statement after a Reuters request for comment, and denied it was related in any way to Russian deliveries of Sputnik V.

The Sputnik V vaccine is based on a two-shot regimen, in which each shot uses a different adenovirus vector to deliver DNA instructions for making coronavirus proteins. Studies of the AstraZeneca vaccine, which is based on a single adenovirus vector, have similarly found increased antibody responses to a second shot with a longer interval since the first shot, although it's not yet clear why.

RDIF has notified all foreign partners and vaccine buyers that prolonging the gap between doses to 90 days helps to slightly increase the immune response, the official said.

Russia's vaccine roll-out involves giving people the second does of Sputnik V after 21 days.

The Philippines Food and Drug Administration said this week it would allow a 42-day interval between doses, after Russia proposed widening the time interval to 90 days.

The Russian health ministry and the Gamaleya Institute did not immediately reply to requests for a comment.