 "Coronavirus, vaccine, covid, drugs, clinical trials")
A new variant of SARS-CoV-2, the virus which causes COVID-19, is thought to be driving increased transmission of the disease in parts of the UK. The government has placed some regions including London under new, stricter coronavirus restrictions, known as Tier 4. People in Tier 4 areas will not be able to gather with anyone outside their household for Christmas, while those in the rest of the country can only gather on Christmas Day itself.
Boris Johnson, the prime minister, and his chief scientific advisors said that the new variant could increase transmission of COVID-19
