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 said on Friday.
Trials will start by the end of the year and Russia wants to jointly produce the new vaccine if it is proven to be effective, said the RDIF wealth fund, which has funded Sputnik V, named after the Soviet-era satellite that triggered the space race.
AstraZeneca, in a statement on Friday, 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. However, its Russian arm said it would start to enrol adults aged 18 years and older to the trial.
The co-operation between one of Britain's most valuable listed companies and the state-backed Russian science research institute highlights the pressure to develop an effective shot to fight the pandemic that has killed over 1.5 million people.
The move is likely to be seen in Moscow as a long-awaited vote of confidence by a Western manufacturer in Sputnik V.
Its Russian developers say clinical trials, still underway, have shown it has an efficacy rate of over 90%, higher than AstraZeneca's own vaccine and similar to US rivals Pfizer and Moderna.
Some Western scientists have raised concerns about the speed at which Russia has worked, giving the regulatory go-ahead for its vaccines and launching large-scale vaccinations with Sputnik V before full trials to test its safety and efficacy have been completed. Russia has rejected such criticism as unfounded.
The prospective tie-up comes as AstraZeneca, once seen as a frontrunner in the vaccine race, prepares for further tests to confirm whether its shot could be 90% effective, potentially slowing its rollout.
The average efficacy rate was 70.4% in interim late-stage data.
The partnership came about after the developers of Sputnik V suggested on Twitter last month that AstraZeneca try the combination after the British drugmaker released interim results from its late-stage trial.
The British drugmaker accepted the proposal, the RFID said on Friday.
"The decision by AstraZeneca to carry out clinical trials using one of two vectors of Sputnik V in order to increase its own vaccine's efficacy is an important step towards uniting efforts in the fight against the pandemic," said RDIF head Kirill Dmitriev in a statement.
"We hope that other vaccine producers will follow our example."
Earlier this week, Kate Bingham, chair of Britain's vaccine taskforce, said the country would start trials next year using combinations of different kinds of vaccine for the initial and booster vaccinations, in the hope that a "mix-and-match" approach might maximise the immune response.
Both projects are using harmless adenoviruses as vehicles to bring genetic instructions into the body to prompt cells to produce vaccine proteins, an approach that has previously been used in an Ebola vaccine.
One common challenge of such a method is that the immune system could attack the adenovirus vehicle, known as the viral vector, and in particular neutralize the staggered booster shot that is now an important feature of the leading Covid-19 vaccine candidates.
Using different viral vectors for the primer and booster shot is one approach that researchers, including at the Gamaleya Institute, have pursued. Combining vaccines from different developers could also be a way around that.
AstraZeneca and partner Oxford University have used a harmless adenovirus only found in monkeys to rule out that people receiving the shot had previous exposure and therefore an immune defence against it.
AstraZeneca did not mention immunity against the viral vector as an issue in its statement on Friday.
Still, Russian officials have not always been complimentary about the British vaccine.
When the company paused a clinical trial in September due to the unexplained illness of a volunteer, Kremlin spokesman Dmitry Peskov told reporters that Sputnik V was a more reliable vaccine because it was based on an adenovirus found in humans, whereas the British candidate was "a monkey vaccine."
The partnership may draw scrutiny after Britain said in July hackers backed by the Russian state were trying to steal Covid-19 vaccine and treatment research from academic and pharmaceutical institutions around the world. The Kremlin rejected the Western allegations.
The news came as Sanofi and GlaxoSmithKline said clinical trials of their Covid-19 vaccine showed an insufficient immune response in older people.