COVID-19 vaccine just before Christmas if it is declared safe and effective, health minister Matt Hancock said on Monday."We're working very closely with the company," he told BBC TV. "We'll be ready to roll it out as soon as it comes, we'll be ready from the first of December..., but more likely is that we may be able to start rolling it out before Christmas."Asked how many vaccines Britain would need, he said it depended on how effective they were at preventing transmission.Last week, Pfizer said its experimental COVID-19 vaccine was over 90% effective based on initial trial results.Britain expects to have 10 million doses of Pfizer/BioNTech's candidate COVID-19 vaccine available by the end of the year.Britain has now ordered 40 million.