Vasundhara Raje no more 'Maharani' as she loses her raj to Cong

London/Milan, Jun 2: World Health Organization experts and a range of other scientists said on Monday there was no evidence to support an assertion by a high profile Italian doctor that the coronavirus causing the COVID-19 pandemic has been losing potency.

Professor Alberto Zangrillo, head of intensive care at Italy's San Raffaele Hospital in Lombardy, which bore the brunt of Italy's COVID-19 epidemic, on Sunday told state television that the new coronavirus "clinically no longer exists".

But WHO epidemiologist Maria Van Kerkhove, as well as several other experts on viruses and infectious diseases, said Zangrillo's comments were not supported by scientific evidence.

There is no data to show the new coronavirus is changing significantly, either in its form of transmission or in the severity of the disease it causes, they said.

"In terms of transmissibility, that has not changed, in terms of severity, that has not changed," Van Kerkhove told reporters.

It is not unusual for viruses to mutate and adapt as they spread, and the debate on Monday highlights how scientists are monitoring and tracking the new virus. The COVID-19 pandemic has so far killed more than 370,000 people and infected more than 6 million.

Martin Hibberd, a professor of emerging infectious disease at the London School of Hygiene & Tropical Medicine, said major studies looking at genetic changes in the SARS-CoV-2 virus that causes COVID-19 did not support the idea that it was becoming less potent, or weakening in any way.

"With data from more than 35,000 whole virus genomes, there is currently no evidence that there is any significant difference relating to severity," he said in an emailed comment.

Zangrillo, well known in Italy as the personal doctor of former Prime Minister Silvio Berlusconi, said his comments were backed up by a study conducted by a fellow scientist, Massimo Clementi, which Zangrillo said would be published next week.

Zangrillo told Reuters: "We have never said that the virus has changed, we said that the interaction between the virus and the host has definitely changed."

He said this could be due either to different characteristics of the virus, which he said they had not yet identified, or different characteristics in those infected.

The study by Clementi, who is director of the microbiology and virology laboratory of San Raffaele, compared virus samples from COVID-19 patients at the Milan-based hospital in March with samples from patients with the disease in May.

"The result was unambiguous: an extremely significant difference between the viral load of patients admitted in March compared to" those admitted last month, Zangrillo said.

Oscar MacLean, an expert at the University of Glasgow's Centre for Virus Research, said suggestions that the virus was weakening were "not supported by anything in the scientific literature and also seem fairly implausible on genetic grounds."

Global health experts on Wednesday said novel coronavirus is here to stay for more than a year and called for aggressive testing to prevent its spread.

In an interaction with Congress leader Rahul Gandhi, health experts Professor Ashish Jha and Professor Johan Giesecke talked about the COVID-19 pandemic as part of the series being aired on Congress social media channels.

While Jha exuded confidence that a vaccine will be available in a year's time, Prof Giesecke said India should practice a lockdown that is as 'soft' as possible, as a severe lockdown will ruin its economy very quickly.

"When the economy is opened up after lockdown, you have to create confidence among people," Harvard health expert Ashish Jha told Gandhi.

Jha is a professor of Global Health at TH Chan School of Public Health and Director, Harvard Global Health institute.

He said coronavirus is a '12-18 months' problem and the world is not going to be free of this till 2021.

The expert also called for the need for aggressive testing strategy for high-risk areas.

Gandhi, while interacting with the experts, said life is going to change post COVID-19.

"If 9/11 was a new chapter, this will be a new book," he remarked.

Professor Johan Giesecke, former chief scientist, European Centre for Disease Prevention and Control said India should have a 'soft lockdown'.

"The situation that India is in, I think, you should have a soft lockdown, as soft as possible," he said.

"I think for India, you will ruin your economy very quickly if you have a severe lockdown. It is better, skip the lockdown, take care of the old and the frail...," he noted.