Milan: The probe for the origin of Covid-19 intensifies as two Italian scientiests on Tuesday said that they were asked by WHO to retest the samples from a study suggesting the coronavirus was circulating outside China by October 2019.
"The WHO asked us if we could share the biological material and if we could re-run the tests in an independent laboratory. We accepted," Giovanni Apolone, scientific director of one of the lead institutions, the Milan Cancer Institute (INT), said.
The move comes amid the growing international pressure to learn more about the origins of the deadly coronavirus that claimed lives of more than 3 million people.
Last week, President Joe Biden had asked the US intelligence agencies to redouble their efforts to find the origin and report back to him in 90 days.
The WHO reacted to President Biden's announcement that intelligence agencies were pursuing rival theories, including the possibility of a laboratory accident in China, by saying the search was being "poisoned by politics".
Covid-19 was first recognized in the central Chinese metropolis of Wuhan in December 2019, whereas Italy's first affected person was detected on Feb. 21 final year in a small city close to Milan.
However, a study published last year suggested antibodies to either the virus or a variant were detected in Italy in 2019.
The study had prompted Chinese state media to suggest the virus might not have originated in China, although the Italian researchers stressed the findings raised questions about when the virus first emerged rather than where.
The WHO's request has not previously been reported.
A WHO spokesperson said that WHO is in contact with the researchers that had published the original paper and that a collaboration with partner laboratories has been set up for further testing.
The spokesman further said that the WHO was aware that the researchers are planning to publish a follow-up report "in the near future".
He said the United Nations agency has contacted all researchers who have published or provided information on samples collected in 2019 that were reported to have tested positive for SARS-CoV-2, but does not yet have the final interpretation of the results.
The Italian researchers' findings, published by the INT's scientific magazine Tumori Journal, showed neutralising antibodies to SARS-CoV-2 in blood taken from healthy volunteers in Italy in October 2019 during a lung cancer screening trial. Most of the volunteers were from Lombardy, the northern region around Milan, which was the first and hardest hit by the virus in Italy.
"None of the studies published so far have ever questioned the geographical origin," Apolone told Reuters.
"The growing doubt is that the virus, probably less powerful compared to later months, was circulating in China long before the reported cases," Apolone added.
The WHO chose the laboratory of the Erasmus University in Rotterdam for the re-test, said Emanuele Montomoli, co-author of the original study and professor of Public Health at the Molecular Medicine Department in the University of Siena.