The one-shot Sputnik Light vaccine has 70% effectiveness against the Delta variant three months after infection, the Russian Direct Investment Fund said.

The data was submitted by the developer, the Gamaleya Institute, to medical website medRxiv ahead of a peer review.

It was based on 28,000 participants who received a dose of Sputnik Light, compared to a control group of 5.6 million individuals who were not vaccinated.

Sputnik Light as a booster for other vaccines will be almost as effective against the Delta variant as Russia’s two-shot Sputnik V vaccine, RDIF said in a statement.

It added that Sputnik Light would be over 83% effective against infection and over 94% effective against hospitalisation.

Kirill Dmitriev, head of the RDIF, told Reuters he expected Sputnik Light to eventually become the main Russian vaccine against COVID.