AFP reports that patients recovering from severe lung infections develop "immunological scars" that stifle their body's immune response and heighten their risk of contracting pneumonia, a common killer of Covid-19 sufferers, researchers said Monday.
Studies in both humans and mice showed that the body's immune response is temporarily switched off after some severe infections, rendering patients more vulnerable to new bacterial or viral diseases.
A team of researchers from the University of Melbourne's Peter Doherty Institute for Infection and Immunity and the University Hospital of Nantes found that the cells that form the immune system's first line of defence - macrophages - were "paralysed" after severe infection.
Macrophages neutralise bacteria and raise an internal alarm that sends immune cells rushing to the site of infection.
Once the threat is taken care of, the macrophages down tools and the body goes back to running as normal.
But by analysing blood samples from patients who had suffered severe infections, researchers found that their macrophages had been deactivated.
This left patients at greater risk of contracting potentially fatal secondary infections such as pneumonia while in hospital.
The team said their findings could influence how hospital infections are treated - including rethinking the systematic use of antibiotics, to which super bugs are increasingly resistant.
The research may have significant implications on how Covid-19 cases are treated in future.
Most Covid-19 deaths occur due to a cytokine storm - a process whereby the body's own immune response runs wild causing acute and often fatal inflammation.
Nigeria to keep 'hotspot' Kano under lockdown for longer
Nigeria's government on Monday extended a coronavirus lockdown on the northern region of Kano after it became a hotspot for new infections, AFP reports.
The head of the country's coronavirus taskforce, Boss Mustapha, said the lockdown on the economic hub - which includes Kano - would be prolonged for two weeks.
The authorities will also start to impose "precision" lockdowns in any other areas that report a "rapidly increasing number of cases, when the need arises", he said.
The outbreak in Kano has become a major cause of concern after medics and residents last month began reporting a spike in deaths.
Nigeria has confirmed 5 959 infections and 182 deaths from the novel coronavirus across the country as of Monday.
Kano is the second hardest hit region with 825 confirmed cases and 36 fatalities.
Denmark to offer testing kits to all adults
Denmark said on Monday it would offer all adults the chance to be tested for the new coronavirus, including those who have no symptoms, as the country recorded its smallest rise in cases in two months, AFP reports.
Until now, only those with symptoms could be tested, once they had received the green light from their doctor.
On Monday, the country registered 41 new cases, the smallest increase since mid-March, bringing the total number to 11 166.
"We've brought the infection rate down to a very low level. It's imperative that there be no hidden pockets of infection that could cause the spread of the virus to increase," Health Minister Magnus Heunicke said.
The test being offered detects an active case of the virus, and is not an antibody test that determines whether a person has been infected at some point.
After announcing strict measures to curb the virus on 11 March, the Scandinavian country was the first in Europe to reopen nursery and primary schools on 15 April.
Since then, a number of restrictions have been eased, including the reopening of hair salons, dentists' practices and tattoo parlours, as well as shopping centres and department stores.
On Monday, cafes, bars and restaurants reopened.