• France on Monday announced that more than 25 000 people had died in the country.
• US President Donald Trump now says his worst-case coronavirus scenario would be 100 000 deaths.
• It is not yet known how or if the novel coronavirus will respond to warmer weather.

As several nations begin relaxing their lockdowns following an initial peak in Covid-19 cases, attention is turning to how they can avoid a "second wave" of infections as social distancing is eased, AFP reports.

Italy and Spain - two of the hardest hit countries - have already started allowing people outside to exercise for the first time in nearly two months, and several US states are allowing businesses to reopen.

In France, where confinement measures are set to lift on 11 May, Prime Minister Edouard Philippe said there is a "fine line" between lifting restrictions on movement and avoiding a new surge in infections of a disease that has killed nearly a quarter of a million people globally.

"The risk of a second wave - which would hit our already fragile hospitals, which would need us to reimpose confinement and waste the efforts and sacrifices we've already made - is serious," he said last week.

Physical distancing has proved effective in flattening the curve of new Covid-19 cases, buying health systems crucial time to recover and regroup. But it has also meant that a very small percentage of populations are likely to have been infected and thus developed immunity.

Some senior health officials - notably in Germany and the US - have warned it could bring even more infections than the March/April peak. Others are more optimistic that changes in personal behaviour could slow new cases.

Pierachille Santus, a lung expert based in Milan, said the second wave "will probably be smaller than the first" thanks to control measures.

It is not yet known how or if the novel coronavirus will respond to warmer weather. Other viruses tend to go dormant during summer months.

Even if businesses can reopen and people return to the streets, there are several ways of slowing the virus spread.

These include keeping your distance from others, avoiding touching your face, washing your hands, wearing a mask while in public - all habits people have, to some extent, picked up during the first wave.

One model run by the Public Health Expertise research group showed that such measures could reduce expected total Covid-19 deaths to 85 000 in France, compared with an anticipated 200 000 with no social distance or mask wearing.

Yet even in the best case scenario of new infections, hospitals are likely to be inundated with fresh patients.

France's death toll hits 25 000

France on Monday announced that more than 25 000 people had died in the country due to the coronavirus epidemic, after a new jump in the daily death toll, AFP reports.

The health ministry said 25 201 people were now confirmed to have died from the virus in the country in hospitals and nursing homes. Over the last 24 hours, 306 people died from Covid-19, double the figure of 135 from the day earlier.

Models suggest US death toll could hit 100 000 next month

US President Donald Trump now says his worst-case coronavirus scenario would be 100 000 deaths, but the country will probably reach that grim milestone by next month, according to several scientific models - none of which predict a summertime halt to the virus's spread, AFP reports.

The country has already seen 68 000 confirmed deaths, and has confirmed about 30 000 new cases a day since early April. The nature of the epidemic is such that more bleak figures are inevitable.

"My personal best guess is that we are going to reach 100,000 deaths around the beginning of June," Nicholas Reich, an associate professor of biostatistics at the University of Massachusetts, told AFP.

Reich's lab has looked at several major epidemiological models created by other institutions to come up with an average trajectory for the epidemic's development.

That average curve indicates the United States can expect to hit 90 000 deaths by 23 May. An upcoming update should extend the predictions through the end of May.

"We're seeing pretty consistently somewhere between 5,000 to 10,000 deaths a week - there are not a lot of reasons to expect it's going to drop quickly," Reich said.

Of nine models cited on 1 May by the US Centers for Disease Control and Prevention, at least three of them predicted that 100 000 fatalities would be recorded in four weeks' time.