Social distancing would be needed for “at least half of the year” to stop intensive care units being overwhelmed, according to official scientific advice.
The Scientific Advisory Group for Emergencies (Sage) recommended alternating between more and less strict measures for most of a year.
Strict measures include school closures and social distancing for everyone.
Less restrictive measures include isolating cases and households.
It comes after Prime Minister Boris Johnson said on Thursday that the UK could “turn the tide” on the coronavirus outbreak within 12 weeks.
Schools in England, Scotland and Wales will close on Friday until further notice – except for vulnerable children and those with a parent identified as a key worker.
More than 65,000 retired doctors and nurses in England and Wales have been asked to return to work in the NHS to help tackle the outbreak.
And the chancellor is set to announce a wage subsidy package to try to protect millions of jobs.
Documents prepared by Sage said alternating measures could “plausibly be effective at keeping the number of critical care cases within capacity”.
Less strict measures would also include social distancing – but just in vulnerable groups.
There would be a delay of two to three weeks between measures being put into place and their impact being felt in intensive care.
The reports also said it was “currently unclear” whether the warmer weather would affect the spread of the virus.
The best estimate of the proportion of people who die after being infected is in the range of 0.5% to 1%, according to the advice.