MOSCOW (Reuters) - Human trials of a COVID-19 vaccine combining a British shot from AstraZeneca and Oxford University with Russia’s Sputnik V vaccine will begin next week in Azerbaijan and some Middle Eastern nations, a Russian official said on Thursday. AstraZeneca said in December it would start clinical trials to test combining the two vaccines to see if this could boost the efficacy of the British shot. Both vaccines involve two doses, an initial shot and a booster, and use harmless adenoviruses as vehicles, or vectors, to carry genetic instructions into the body to prompt cells to produce antibodies. Sputnik, however, uses different viral vectors for its two shots. A two-dose regimen of Sputnik V was 91.6% effective against symptomatic COVID-19, according to peer-reviewed late-stage trial results published in The Lancet international medical journal. Russia is ready to offer a collaboration with Sputnik V to any producer that has a vaccine with efficacy less than 90%, Kirill Dmitriev, the head of Russia’s RDIF sovereign wealth fund, told Reuters on Thursday. Pooled late-stage trial data showed AstraZeneca’s shot was about 70% effective. Britain also launched a trial on Thursday to assess immune responses if a dose of AstraZeneca’s vaccine is combined with one from Pfizer and BioNTech in a two-shot schedule. “Sputnik was the first in the world to suggest that the two shots should be different to give a stronger and longer immune response, more mutation-proof,” Dmitriev said. “So what others are starting to do with this kind of trial is to follow our steps,” he said, adding RDIF would also announce a joint trial with a large Chinese company soon. He said hundreds of people in different countries would participate in the trial with AstraZeneca. It has already been approved by several regulators and patient recruitment started last week, Sputnik V’s official Twitter account said. Trials will also be held in Argentina, Saudi Arabia, the UAE, Belarus, Russia, Ukraine and elsewhere, Reuters has reported. Participants will first receive the AstraZeneca vaccine and then the Sputnik V shot 29 days later. The first results are expected in March, Dmitriev said.