The UK government should avoid “setting dates” for when to lift lockdown and instead react to changing circumstances, a scientist has warned.
Prof Graham Medley, a member of the Scientific Advisory Group for Emergencies, said leaders should not be “driven by a calendar”.
Meanwhile, the government has said all over-50s should be vaccinated by May.
And a senior Conservative MP has told the BBC that Downing Street should be “looking to open up” society.
Sir Graham Brady, who leads the 1922 Committee of Conservative Party backbenchers, cited the falling infection level and success of the vaccine rollout, telling the BBC the situation was “optimistic”.
But Prof Medley – who chairs the modelling group SPI-M, which advises Sage – told the BBC’s Today programme that the epidemic could still go in two directions, up or down, and “it’s up to the government to decide which of those paths it takes”.
He urged a strategy of “adaptive management so you actually change the control of the epidemic as it goes along rather than setting dates, for example.”
This means rather than setting dates of when rules could ease, there would be some sort of threshold of what the government would do if certain criteria are met.
“To actually make decisions dependent on the circumstances, rather than being driven by a calendar of wanting to do things,” Prof Medley added.
The government has always insisted it is guided by the science – but Prime Minister Boris Johnson has often given dates when expressing hope about the future of the pandemic, for example saying things will be better by Easter and being hopeful about summer holidays.
Asked what type of circumstances the decisions could be based on, Prof Medley said case numbers were important.
“Vaccination offers a way out and it does reduce the impact of infection, but it doesn’t remove it completely,” he said. “And so case numbers are still important because they represent the risk of having to go back into some kind of national measures.
“At the moment, we’re in a relatively good position in a sense that the number of cases are falling, but they’re still very high. So we only need one more doubling time, one more return to exponential growth, and we could be back in the same pos