It is a unique collaboration: UK and Russian scientists have joined hands to try out a cocktail of the Oxford-AstraZeneca and Sputnik V vaccines to see if it can enhance protection against Covid-19, reports BBC.
The rationale seems to be that mixing of two similar vaccines could elicit a better immune response in people. Only trials can reinforce the finding though; these are likely to be held in Russia among those over 18.
It may make sense to mix the two vaccines: Both use harmless viruses to deliver the important part of the vaccine (a bit of the coronavirus' genetic code) into the body. The hope is that combining the two will impart either stronger or longer-lasting immunity against the virus.