AstraZeneca will start clinical trials to test a combination of its experimental Covid-19 vaccine with Russia's Sputnik V shot aimed at boosting the efficacy of the British drugmaker's vaccine, Russia's sovereign wealth fund has said.

Trials will start by the end of the year, said the RDIF wealth fund, which has funded Sputnik V, named after the Soviet-era satellite that triggered the space race.

In a statement, AstraZeneca said it was considering how it could assess combinations of different vaccines, and would soon begin exploring with Russia's Gamaleya Institute, which developed Sputnik V, whether two common cold virus-based vaccines could be successfully combined.

It did not give further details, Reuters reported.