UK Prime Minister Boris Johnson has warned against relaxing efforts to fight the coronavirus pandemic amid looming hopes of a vaccine against the fast-spreading disease. "We cannot rely on the news about a vaccine as a solution" in fighting the Covid-19 pandemic, Xinhua news agency quoted Johnson as saying at a virtual press briefing in Downing Street on Monday.

"It would be a mistake to slacken our resolve in fighting the virus," the Prime Minister said. Mass testing can be a substitute to the restrictions, he said, adding that it was now more important than ever that people follow the lockdown rules. "Hands, face, space. Follow the rules -- that's how we can protect the NHS (National Health Service), save lives, and get the virus back in its box," he added.

A vaccine candidate jointly developed by the German pharmaceutical company BioNTech SE and the US company Pfizer Inc. has proved to be more than 90 per cent effective in preventing Covid-19 infection in participants with no proven previous SARS-CoV-2 infection, the two companies announced on Monday.

"We've cleared one significant hurdle but there are several more to go before we know the vaccine can be used," said Johnson. On November 5, England entered into a month-long national lockdown, the second of its kind since the onset of the pandemic in the country. Under the lockdown, people in England will only be allowed to leave their homes for specific reasons, such as education, work or food shopping.

Pubs, bars and restaurants will close across the country except for takeaways. Non-essential shops, hairdressers and leisure and entertainment venues will also be shut. Unlike in the first lockdown, schools, colleges and universities will remain open and those who cannot work from homes, such as construction or manufacturing workers, will be encouraged to continue going to their workplaces. As of Tuesday, the UK's overall coronavirus caseload and death toll stood at 1,216,747 and 49,329, respectively.