One-shot Sputnik Light COVID-19 vaccine was found to be 70 percent effective against infection with the Delta variant during the first three months after vaccination, Gamaleya Center analysis shows.

Sputnik light is the first component of the Sputnik V vaccine.

The single dose vaccine is over 75 percent effective in those under the age of 60. It has demonstrated a superior efficacy compared with some two-shot vaccines, which have shown a major decline in efficacy against the Delta variant to less than 50 percent five months after injection, the Russian Direct Investment Fund (RDIF) and Gamaleya Centre said.

The analysis was conducted based on data from 28,000 participants who had received a single dose of Sputnik Light, compared with a control group of 5.6 million individuals who were not vaccinated. The data was collected in July 2021 in Moscow.

The data shows that "Sputnik Light remains highly effective months after vaccination. The results obtained during the study significantly exceed those of some other vaccines, as previously published in scientific media," Gamaleya Center Deputy Director Denis Logunov said.

"The vaccine’s one-shot regimen makes it is a strong solution for countries with low vaccination rates," he added.

The efficacy analysis of Sputnik Light against the Delta variant has been submitted to the medRxiv website for publication this week.

Efficacy of Sputnik Light as a booster against Delta variant for other vaccines is close to the efficacy against the Delta variant of the Sputnik V vaccine – over 83 percent against infection and over 94 percent against hospitalisation, the RDIF & Gamaleya Centre said.

The one-shot vaccine also has a number of advantages, including ease of administering the vaccine, monitoring and more flexible re-vaccination schedule when used as a booster, they added.

In particular, the vaccine has demonstrated efficacy of between 78.6-83.7 percent among the elderly in Argentina.

Sputnik Light is based on the human adenovirus serotype 26, the first component of Sputnik V – the world’s first registered vaccine against coronavirus.

It has been authorised for use in over 15 countries. The one-shot vaccine is now used both on a standalone basis and studied in combination with vaccines from other producers in multiple countries.