Russia has given the green light for clinical trials combining a British shot from AstraZeneca and Oxford University with Russia's Sputnik V vaccine to go ahead, according to Russia's state drug register.

The health ministry's ethical committee had in May suspended the approval process for the clinical trials, and requested additional information.

According to the state drug register, five Russian clinics will hold trials that are set to finish in early March, 2022.

Both the Oxford University-AstraZeneca and Sputnik V vaccines involve two doses – an initial shot and a booster – but Sputnik V uses different viral vectors for its two shots.

Russian Direct Investment Fund (RDIF), which promotes the use of the Sputnik V vaccine, has welcomed the decision to go ahead with the trials.

"Currently, RDIF is conducting joint clinical trials to combine the first component of Sputnik V – the Sputnik Light vaccine – with vaccines from other foreign manufacturers," it said in a statement.

"In particular, the Sputnik Light vaccine can be used in combination with other vaccine to increase their effectiveness including against new variants appearing as a result of the mutation of the virus."

So-called viral vector shots use harmless modified viruses as vehicles, or vectors, to carry genetic information that helps the body build immunity against future infections.

Human trials of a COVID-19 vaccine combining the Oxford University-AstraZeneca shot with Sputnik V had already been approved in Azerbaijan, the United Arab Emirates, Belarus and Argentina.