Less than 4% of people tested in parts of the UK had antibodies for the coronavirus, the government’s top science adviser has said.
The tests, which can show if someone had the disease and produced antibodies for it, could indicate the level of immunity the country has built up to the virus.
But Sir Patrick Vallance told Monday’s COVID-19 press briefing that while tests run in London showed a higher amount of people had been positive for antibodies, other parts of the country were much lower.
He spoke about tests that were run about two weeks ago – when the subject would have had the virus about three weeks earlier to that.
Vallance said: “There it looks like in London it might be, from that time, maybe 10% of people (were) positive for antibody, suggesting that’s the sort of range of infection, and across the country (there are) different levels in different places but on average (it’s) somewhere around 4%, something like that.”
The low positive return from the tests follow previous reports that half of the UK’s population had been infected.
They followed an Oxford University study, which ran models under various scenarios, with one suggesting 68% of the population could have been infected by 19 March.
If accurate, and if half the population had developed resistance to the coronavirus, then talk of herd immunity could have started coming back into play.
Herd immunity is built up when so many people have resistance to a virus – usually through vaccination – they can stop it transmitting to those not immune or unable to be vaccinated. It was a strategy reportedly once under consideration by the government but abandoned.
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Meanwhile, Boris Johnson defended the government’s messaging on coronavirus over the past two days which critics have said is confusing.
The message has changed, in England, from staying at home to staying alert.
“We’re now asking people to stay alert, control the virus and save lives and yes, staying alert for the vast majority of people still means staying at home as much as possible,”
“But there are a range of other actions we’re advising people to take as we modify our measures.
“People should stay alert by working from home, if you can, limiting contact with other people.”
Earlier on Monday, the government published a strategy that gave some more detail on the slightly eased lockdown measures announced by Johnson on Sunday.
There was criticism that the government’s messaging on coronavirus over the past two days has been confusing.
The adjusted measures are to take effect from Wednesday.
People who cannot work from home should be ready to go to their job if it is safe to do so, but should try and avoid public transport.
Walking and cycling was encouraged, with employees asked to drive cars if necessary.
It will be possible to leave the house for exercise more than once a day, with the government having previously limited how often someone can go out.
Sunbathing will also return, with police having moved on anyone visiting parks and open spaces for unnecessary reasons as they enforced lockdown rules.
Johnson said on Sunday that you “can sit in the sun in your local park, you can drive to other destinations, you can even play sports – but only with members of your own household”.
However, with devolved administrations expressing wariness at changing the “stay at home” message to “stay alert”, people in England have been warned from crossing into Scotland or Wales for leisure if the rules there are different.
The slightly relaxed measures will be enforced with higher fines, which reflect the increased risk that social distancing will not be practised by some.
The two metre rule will remain in force, but it will be possible to meet up with one person from outside your household, outdoors, provided you keep at least that distance between you and them.
Speaking on Monday ahead of Johnson’s evening conference, leader of the opposition Sir Keir Starmer said: “What we needed from the prime minister last night was clarity and reassurance.
“The prime minister said he was setting out a road map, but if we’re to complete the journey safely a road map needs clear directions. So many of us have questions that need answering.”
A series of pledges have also been outlined by the government, promising to invest in technology and adjust social distancing measures as needed to control the pandemic.
A rough outline shows how some school years and shops could begin opening from next month if the coronavirus is not spreading too quickly while pubs and restaurants will stay shut until July at the earliest.