The government has reversed a controversial decision to withhold information about the geographical spread of the coronavirus, as England’s chief medical officer admitted a “communications fumble”.

On Wednesday, the Department of Health said the government would stop providing daily updates on the location of patients who had tested positive “due to the number of cases” following a 70% increase. The decision prompted accusations of secrecy and concerns that it would lead to the spread of fake news.

But on Thursday morning Prof Chris Whitty announced a U-turn, saying the government would provide daily updates but they would be delayed by 24 hours to allow time for information to be verified.

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Speaking to the Commons health committee he said: “I think we had a bit of a communications fumble on this one. We are intending to provide geographical information.

“We are intending to have some delay of about 24 hours to be absolutely sure we’ve got the details right. I think we do intend to continue with these geographical things. And in fact, in due course, will use maps and other things to enhance that.”

Whitty also said the UK has mainly moved into the “delay phase” of tackling the virus, meaning measures to tackle the disease would be stepped up.

He said: “We have moved from a situation where we are mainly in ‘contain’, with some ‘delay’ built in, to we are now mainly ‘delay’,” he said, although elements of the contain process remained in place.

The government’s battle plan says of the “delay” phase: “Action that would be considered could include population distancing strategies (such as school closures, encouraging greater home working, reducing the number of large-scale gatherings) to slow the spread of the disease throughout the population, while ensuring the country’s ability to continue to run as normally as possible.”

Whitty said he did not expect the death rate from Covid-19 to go above 1% and it may even be lower once it was possible to test and count the people who are infected but have no symptoms.

“I am reasonably confident 1% is the upper rate of mortality,” he said. When the director general of the World Health Organization spoke of 3.4%, he was dividing the number of reported deaths by the number of reported cases. “That isn’t the mortality rate,” said Whitty.

“If you are missing all the mild cases, all the asymptomatic cases, you end up with an exaggerated view of what the mortality rate is.”

For younger people, the mortality rate is well below 1%, he said. It rises with age, but he said, “more than 90% of over-80-year-olds survived it even in a stretched health service in China. The great majority of people will survive this, even if they are in their 80s.”

Older people who may be more vulnerable should not isolate themselves at this stage of the UK epidemic, he said, although they may be advised to do so when the peak comes. If they cut themselves off too soon, they may suffer loneliness and have difficulties getting food and other supplies they need.

The UK has effectively already moved into the second stage of its response – the delay phase – he said, which implies acceptance that the epidemic will come and can no longer be contained to a few cases and stamped out. The objective now was to track down every case and their contacts and isolate them so that it spreads more slowly and the peak comes later.

That buys time for the trials of anti-viral drugs currently being tested in China – principally Kaletra, which is an HIV drug, and remdesivir, which was tried and failed against the Ebola virus. Whitty said he thought they could prove useful, if only for those people with severe illness. Delay into the summer months also may reduce the intensity of the epidemic, because people open windows and go outdoors, where they are much less likely to get infected. The virus spreads at close quarters, as it did in the ski chalet in France where the first British people were infected.

Whitty said the virus spreads in water droplets when people cough and also on surfaces. In a tube train, he said, the virus from the hand of somebody who is infected might last on a rail for 48 or even 72 hours. But it would only be transmitted to another passenger if they touched the rail and then put their hand to their eyes, nose or mouth, which is why handwashing, preferably with soap and water, and not touching the face are the best protective measures anyone can take.

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At its peak in Hubei province, China, where the coronavirus emerged, Whitty said the prevalence in the population was thought to be around 20%, and the numbers are now dropping. But China still has some robust control measures remaining to stop people moving about and infecting others. When those are lifted, it is possible the numbers could rise again, he said. The UK is planning for the worst case scenario, which is up to 80% infected, while hoping for the best, which would be 20%.

If at the peak, the epidemic hits the top end of the range, “there will be a period when the NHS has great pressure on it for a brief period of time”. He thought recently retired doctors and nurses could volunteer to help in the event of inevitable staff shortages, but not necessarily in patient-facing roles. They could staff the NHS 111 call service, for instance.

Closing schools, he said, would not necessarily be helpful. Children would mix anyway and it would mean some parents unable to work, with impact on the economy. It is also known from China that children are far less likely to get the virus than adults.

He stressed that the UK would get through this: “There will be a beginning, a middle and an end.” No vaccine would be ready for at least a year, but would be useful for the future if the disease became endemic.

• This article was amended on 9 March 2020 to clarify details around the prevalence of coronavirus in China.