Airport gunman charged, US seeks death penalty

Beijing, May 24: The Chinese virology institute in the city where COVID-19 first emerged has three live strains of bat coronavirus on-site, but none match the new contagion wreaking chaos across the world, its director has said.

Scientists think COVID-19 -- which first emerged in Wuhan and has killed some 340,000 people worldwide -- originated in bats and could have been transmitted to people via another mammal.

But the director of the Wuhan Institute of Virology told state broadcaster CGTN that claims made by US President Donald Trump and others that the virus could have leaked from the facility were "pure fabrication".

"Now we have three strains of live viruses... But their highest similarity to SARS-CoV-2 only reaches 79.8 percent," she said, referring to the coronavirus strain that causes COVID-19.

US demands immediate start to WHO review

The United States called on the World Health Organisation on Friday to begin working immediately on investigating the source of the novel coronavirus, as well as its handling of the response to the pandemic.

One of their research teams, led by Professor Shi Zhengli, has been researching bat coronaviruses since 2004 and focused on the "source tracing of SARS", the strain behind another virus outbreak nearly two decades ago.

"We know that the whole genome of SARS-CoV-2 is only 80 percent similar to that of SARS. It's an obvious difference," she said.

"So, in Professor Shi's past research, they didn't pay attention to such viruses which are less similar to the SARS virus."

Conspiracy rumours that the biosafety lab was involved in the outbreak swirled online for months before Trump and US Secretary of State Mike Pompeo brought the theory into the mainstream by claiming that there is evidence the pathogen came from the institute.

The lab has said it received samples of the then-unknown virus on December 30, determined the viral genome sequence on January 2 and submitted information on the pathogen to the WHO on January 11.

Wang said in the interview that before it received samples in December, their team had never "encountered, researched or kept the virus."

"In fact, like everyone else, we didn't even know the virus existed," she said. "How could it have leaked from our lab when we never had it?"

The World Health Organization said Washington had offered no evidence to support the "speculative" claims.

In an interview with Scientific American, Shi said the SARS-CoV-2 genome sequence did not match any of the bat coronaviruses her laboratory had previously collected and studied.

Canadian researchers are developing a DNA vaccine for SARS-CoV-2, the coronavirus that causes COVID-19 and has currently infected nearly 5,00,000 people worldwide and crippled the global economy.

Entos Pharmaceuticals, a health-care biotechnology company headed by a University of Alberta researchers, develop new therapeutic compounds using the company's proprietary drug-delivery platform and has begun manufacturing vaccine candidates against the novel coronavirus.

"Given the urgency of the situation, we can have a lead candidate vaccine within two months. Once we have that it's a race to get it into clinical trials," said John Lewis, CEO of Entos and a Professor at the University of Alberta in Canada.

Lewis said in comparison to a traditional vaccine, DNA-based vaccines hold several advantages.

Nucleic acids are introduced directly into the patient's own cells, causing them to make pieces of the virus--tricking the immune system into mounting a response without the full virus actually being present, the researcher said.

According to the company, the approach is recognised as being easier to move into large-scale manufacturing, offers improved vaccine stability and works without needing an infectious agent.

In the current absence of a vaccine for COVID-19, several companies around the world are mounting efforts to begin similar work.

The first clinical trial using a DNA-based vaccine developed by Moderna Inc.in the US on March 13.

Their approach allows for antibodies to be made in the human trial volunteers against a specific protein on the surface of the coronavirus that lets the virus enter human cells.

The hope is that the antibodies will stop the interaction.

Though this approach is designed to be effective against COVID-19 specifically, Lewis said Entos is taking a different tack.

The company plans to use plasmid DNA to amplify the production of key coronavirus surface and structural proteins with each injection, with an eye to the bigger picture.

"Many of the structural proteins in the virus are pretty well conserved across all the coronaviruses, including SARS and MERS," said Lewis.

"We're hoping that if we express more of the structural proteins that are common to most coronaviruses, we can inhibit the current COVID-19, and also potentially protect against all coronaviruses both past and future," Lewis added.

To move the project forward quickly, the company is seeking financial support from both provincial and federal levels of government.

"We have the opportunity to save a lot of lives, and I think it's really upon us and governments to find solutions for that," Lewis said.

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."