A professor has suggested that people will not go to work if they have a respiratory illness after the pandemic.
Professor Dame Angela McLean, chief scientific adviser at the Ministry of Defence, told the Science and Technology Committee that is was "quite unlikely" for a full return to how society was before the pandemic struck.
"I suspect we just won't go to work if we have a respiratory illness," she said.
When asked whether this would be mandated, she added: "It would be most powerful if it became socially unacceptable to go to work with a cough."
The professor said: "Things are all moving in the right direction: infections are falling, the number of cases are falling, hospitalisations and deaths.
"But we still stand with a high number of infections.
"There were about 20,000 people in hospital earlier this week. By comparison, in early May there were about 15,000 patients but there's still a lot of people in hospital.
"I share everybody's optimism about how fantastic this vaccine is. But I would say we need to be optimistic and cautious, there's still a lot of infected people out there."
On how likely children are to bring infection into their home, she added: "Particularly when schools are open, children are quite often the first person that's infected in a household."
When asked about the easing of the first lockdown, she said: "Caution was our friend - we did actually ease it pretty slowly and I would say things went very well.
"From May to September I would give a big tick and say that was well managed.
"In November we were hit with that new variant and, with hindsight, we came out of the November lockdown too early."
Boris Johnson said easing England's lockdown will be based on a "cautious and prudent approach".
The Prime Minister was responding to whether he agreed with Professor Dame Angela McLean's comments to the Science and Technology Committee that any unlocking should be based on "data, not dates".
Speaking at a mass vaccination centre in Cwmbran, south Wales, Mr Johnson said: "I do think that's absolutely right.
"That's why we'll be setting out what we can on Monday about the way ahead and it'll be based firmly on a cautious and prudent approach to coming out of lockdown in such a way to be irreversible.
"We want to be going one way from now on, based on the incredible vaccination rollout that you're seeing in Cwmbran."
