The hypothesis that the Covid-19 pandemic was triggered by a virus unintentionally escaped from a research laboratory in China resumes strength.
"The spillover with an animal-human species jump could have been carried out for accidental causes by a bat virus experimentally adapted to grow in vitro", explains today Giorgio Palù, virologist and president of the Italian drug agency, in an interview with Courier service.
"The prototype Wuhan strain, the one that began to manifest itself in China with severe forms of pneumonia, and all the resulting variants, even those considered uninteresting in the international classification, have a very peculiar characteristic", continues Palù. "In the gene that produces the Spike protein (the one that the virus uses to attach the cell to be infected), a sequence of 19 letters belonging to a human gene and absent from all the genomes of human, animal, bacterial, plant viruses appears inserted. so far sequenced. The probability of this being a random event is roughly one in a trillion. An essential sequence because it gives the virus the ability to fuse with human cells and to cause disease ".
“We can hypothesize - he adds - a manipulation carried out for research purposes only, certainly not with malicious intentions. It would not be the first time that a virus escapes by mistake from a high-security laboratory ”.
On the origin of the virus from bats, according to Palù “the queen proof that supports the natural origin is missing. On the one hand, the intermediate host has not yet been found and on the other, RaTG13, the Bat virus Rhinolophus affinis whose genome is 97% identical to Sars-CoV-2, has little ability to infect us. To validate which of the hypotheses in the field (natural or laboratory spillover) is more likely, the collaboration of the Chinese authorities would be highly desirable, as repeatedly requested by the WHO and the scientific community ".
(Unioneonline / vl)