LONDON -- Normality could be within reach when all those over 50 years old have been vaccinated in Britain, a British government's advisory scientist said Thursday.

Andrew Hayward, a member of the government's Scientific Advisory Group for Emergencies, said: "Once the most vulnerable people, particularly those over 50 and those with chronic illnesses, are vaccinated then yes I think we can see a significant return to normality."

"That, in addition to the fact coronavirus is a seasonal disease, I think will make a big difference and allow us to open up," he told the BBC.

"I think what we'll see is a phased opening up as the vaccination levels increase, and then we will be more or less back to normal for the summer, I would imagine."

Earlier Thursday, vaccine minister Nadhim Zahawi told lawmakers that almost nine in 10 over 80s and over 75s, and over half of people in their 70s, have now been vaccinated in Britain.

British Health Secretary Matt Hancock confirmed that Britain remains "on track" to complete the vaccination of the top priority groups, which cover 15 million people, by mid-February.

Meanwhile, one in five of all adults in Britain have already received a jab, according to Hancock. Britain aims to offer all adults their first dose by autumn.

Chief Medical Officer for England Chris Whitty said Wednesday at a Downing Street press briefing that it looks as if Britain is "past the peak" of its current wave, but he warned of another peak if restriction is relaxed too soon.

Meanwhile, other experts have warned that some restrictions, such as border control, would still be in place as Britain is still threatened by virus variants from abroad, even if the whole British population is vaccinated.

Another 20,634 people in Britain have tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 3,892,459, according to official figures released Thursday.

The country also reported another 915 coronavirus-related deaths. The total number of coronavirus-related deaths in Britain now stands at 110,250. These figures only include the deaths of people who died within 28 days of their first positive test.

England is currently under the third national lockdown since the outbreak of the pandemic in the country. Similar restriction measures are also in place in Scotland, Wales and Northern Ireland.

To bring life back to normal, countries such as Britain, China, Germany, Russia and the United States have been racing against time to roll out coronavirus vaccines.