He announced that, from today, anyone with a continuous cough or high temperature must isolate themselves by staying at home for seven days. Entire households where just one person has symptoms could later be asked to go into quarantine as the outbreak spreads in the coming weeks. And in a chilling prediction of a fast-growing mortality rate, the Prime Minister said: “I must level with you, level with the British public – many more families are going to lose loved ones before their time.”
In other measures announced last night, older people were advised not to take cruise holidays and schools were told to cancel foreign trips.
But the Prime Minister stopped short of extreme measures including banning mass public gatherings and closing schools after evidence suggested such moves would have little impact in the short term.
His expert advisers indicated that the elderly and vulnerable could be told to isolate themselves for up to 14 weeks during the peak of the outbreak.
Mr Johnson, flanked by his chief medical and scientific advisers, gave his grim warning at a Downing Street news conference after chairing a meeting of his Cobra emergency planning committee.
Boris Johnson warns people their loved ones might die
Boris Johnson, Matt Hancock and his medical experts
He confirmed that the Government effort to contain the virus had now concluded and Whitehall was switching efforts to drastic measures to delay the peak of infections until the early summer to minimise the impact on the NHS.
Official figures confirmed yesterday that 596 cases of coronavirus have been recorded in the UK with 10 people dead.
Mr Johnson said: “It’s clear that coronavirus, COVID-19, continues and will continue to spread across the world and our country over the next few months. We’ve done what can be done to contain this disease and this has bought us valuable time. But it is now a global pandemic.
“And the number of cases will rise sharply and indeed the true number of cases is higher – perhaps much higher – than the number of cases we have so far confirmed with tests.
How the UK is coping
“I’ve got to be clear, we’ve all got to be clear, that this is the worst public health crisis for a generation.”
Mr Johnson said coronavirus was “more dangerous” than seasonal flu because of the lack of immunity in the population.
He confirmed that the Government was moving to the second phase of his action plan in an attempt to “flatten” and delay the impact of the virus.
Successfully delaying the peak could cut the number of infections in half at the height of the outbreak and reduce the death rate by 20 percent, according to his medical advice.
Mr Johnson said: “If we delay the peak even by a few weeks, then our NHS will be in a stronger state as the weather improves and fewer people suffer from normal respiratory diseases, more beds are available and we’ll have more time for medical research.
“We can also act to stretch the peak of the disease over a longer period so that our society is better able to cope.”
The Prime Minister said measures had to be deployed at the “right time to maximise their effect.”
He said: “The most important task will be to protect our elderly and most vulnerable people during the peak weeks when there is the maximum risk of exposure to the disease and when the NHS will be under the most pressure.
“So the most dangerous period is not now but some weeks away depending on how fast it spreads.”
Setting out the advice to anyone with possible coronavirus symptoms, he said: “If you have coronavirus symptoms, however mild – either a new continuous cough or a high temperature – then you should stay at home for at least seven days to protect others and help slow the spread of the disease.
“We advise all those over 70 and those with serious medical conditions against going on cruises and we advise against international school trips.
“At some point in the next few weeks, we are likely to go further and if someone in a household has those symptoms, we will be asking everyone in the household to stay at home,” the Prime Minister said.
People with mild symptoms were urged not call the NHS 111 helpline in order to stop the service being swamped.
Full details about how people with symptoms should go about isolating themselves are available on the NHS website.
Mr Johnson said the Government was stopping short of banning major public events such as sporting fixtures because evidence showed it would have “little effect on the spread.”
Boris Johnson addresses the children
He added: “But there is also the issue of the burden that such events can place on public services.
“So we’re discussing these issues with colleagues in all parts of the United Kingdom and will have more to say shortly about the timing of further action in that respect.”
His decision contrasted with the Scottish Government, with First Minister Nicola Sturgeon announced a ban on gatherings of more than 500 people from Monday to ease the strain on the NHS.
Mr Johnson said: “We are not – repeat not – closing schools now.
“The scientific advice is that this could do more harm than good at this time.”
He admitted his measures “will cause severe disruption across our country for many months”.
Coronavirus UK: Cases in the UK mapped using figures from the Department of Health and Social Care
And in a direct plea to older citizens, the Prime Minister said: “This disease is particularly dangerous for you, for older people, even though the vast majority this will be a mild to moderate illness, I know that many people will be very worried.
“And I think we should all be thinking about our elderly relatives, the more vulnerable members of their family, our neighbours, and everything we can do to protect them over the next few months.
“We’re going to need to mobilise millions of people to help and support each other.
“And I just want to you to know that the government will do all we can to help you and your family during this period.”
He added: “We will get through this, this country will get through this epidemic, just as it has got through many tougher experiences before if we look out for each other and commit wholeheartedly to a full national effort.”
Speaking alongside the Prime Minister, Chief Medical Office Chris Whitty, acknowledged the advice to people to self-isolate for seven days was “something which will interfere with their lives and interfere with their work and their social life in quite significant ways” but “helps to protect older and more vulnerable people”.
He added: “By seven days the great majority of people are not infectious and it is fine for them to go back into society.”
Chief Scientific Adviser Sir Patrick said the UK was likely to have between 5,000 and 10,000 coronavirus cases at present.
“Currently we are on a trajectory that looks as though it is about four weeks or so behind Italy and some other countries in Europe,” he said.
“There are currently 590 cases that have been identified in the UK and there are more than 20 patients in intensive care units.
“If you calculate what that really means in terms of the total number, it is much more likely that we have between 5,000 and 10,000 people infected at the moment. That is still a relatively small number.”