Coronavirus has weakened and could die out on its own without a vaccine, an Italian doctor has claimed – but many scientists do not agree.
Professor Matteo Bassetti, head of infectious diseases at Genoa’s San Martino General Hospital, believes the Covid-19 virus is “changing in severity” and patients who would once have died quickly are now surviving.
“It was like an aggressive tiger in March and April but now it’s like a wild cat,” he claimed to the Sunday Telegraph.
“Even elderly patients, aged 80 or 90, are now sitting up in bed and they are breathing without help.
“The same patients would have died in two or three days before.”
He claims the virus may have mutated to become less deadly, resulting in fewer deaths.
Or people may simply be receiving smaller doses of the virus when they get infected, because of social distancing and lockdown rules.
The Professor added: “The clinical impression I have is that the virus is changing in severity.
“In March and early April the patterns were completely different.
“People were coming to the emergency department with a very difficult to manage illness and they needed oxygen and ventilation, some developed pneumonia.
“Now, in the past four weeks, the picture has completely changed in terms of patterns.
“There could be a lower viral load in the respiratory tract, probably due to a genetic mutation in the virus which has not yet been demonstrated scientifically.”
The claims have not been well received in the scientific community.
At the start of June, in response to Professor Bassetti’s claim, Dr Angela Rasmussen, from Columbia University, tweeted: “There is no evidence that the virus is losing potency anywhere.”
She added less transmission means fewer hospitalisations and deaths – but warned: “That doesn’t mean less virulence.”
The virulence of a virus is how dangerous the illness is – but may not be directly related to how contagious it is.
Dr Oscar MacLean, of the University of Glasgow, added: “These claims are not supported by anything in the scientific literature, and also seem fairly implausible on genetic grounds.
“The vast majority of SARS-CoV-2 mutations are extremely rare, and so whilst some infections may be attenuated by certain mutations, they are highly unlikely to be common enough to alter the nature of the virus at a national or global level…
“Making these claims on the basis of anecdotal observations from swab tests is dangerous.
“Whilst weakening of the virus through mutations is theoretically possible, it is not something we should expect, and any claims of this nature would need to be verified in a more systematic way.
“Without significantly stronger evidence, no one should unnecessarily downplay the danger this highly virulent virus poses, and risk the ongoing society-wide response.”
Dr Seema Yasmin, an epidemiologist from Stanford University, said the idea was “bulls**t.”