World faces around 4,000 COVID-19 variants as researchers explore mixed vaccine shots
GUY FAULCONBRIDGE and ALISTAIR SMOUT THE world faces around 4,000 variants of the virus that causes COVID-19, prompting a race to improve vaccines, Britain said on Thursday, as researchers began to explore mixing doses of the Pfizer and AstraZeneca shots. Thousands of variants have been documented as the virus mutates, including the so-called British, South African and Brazilian variants which appear to spread more swiftly than others. British Vaccine Deployment Minister Nadhim Zahawi said it was very unlikely that the current vaccines would not work against the new variants. "Its very unlikely that the current vaccine won't be effective on…