The researcher of the Higher Council for Scientific Research (CSIC) at the Institute of Biomedicine of Valencia (IBV-CSIC), Iñaki Comas, has shown that the rate of SARS-CoV-2 coronavirus mutation, the virus that causes Covid-19, is low and is not related to its virulence.

The project, led by him and Fernando González, a scientist at the Institute for Integrative Systems Biology (I2SysBio, a mixed center of the CSIC and the University of Valencia), is based on using genomic epidemiology tools to compare the coronavirus genome from infected patients and thus be able to trace the path that has been traced during the pandemic.

So far, the team led by this biologist and genomics expert has observed that there were multiple introductions of SARS-CoV-2 in Spain, but that only a few caused a large number of infections. “The explanation could be found in large super-dispersing events, which made it easier for the virus to continue among the population,” said the expert.

As he has assured, it is clear that “there has not been” a ‘patient 0’ unsurprisingly, since experts have detected hundreds of introductions, on the order of 700 on the low side, which generated larger or smaller outbreaks. “Some of them are here to stay and have been responsible for a large number of cases in the pandemic. In total we have detected 18 genotypes, which have been responsible for 73% of the cases we analyze. We are closing the analysis to be able to present the results as soon as possible, “he added.

Therefore, he adds, although there were multiple introductions in Spain, only a few were epidemiologically successful, which may be due to the fact that they were associated with “large super-dispersive events”, which allowed the virus to remain among the population. “This is what we are studying right now. We also know that the virus has a relatively low mutation rate (two mutations per month) and that none of the mutations appears to have had a high impact on epidemiology or virulence of the virus“, he insisted.

In his view, unlike in other infectious diseases, the superdispersion event is common and could be behind the initial success of the virus. “The term refers to the fact that a few infected are capable of infecting a large number of people, while the vast majority do not transmit the virus. In the case of the coronavirus, it is estimated that 10% of those infected contributes to a 80% of transmissions. It generally occurs when an infected person encounters circumstances that amplify transmission: closed space, many people, close contact without a mask and poor ventilation, “he added.

Finally, the scientist has warned that it is time to act against the coronavirus, since if Spain remains at the current contagion numbers, the system will endure. “The responsibility is collective and individual. Governments must put the means, but citizens must do their part to avoid unnecessary outbreaks. Lowering the transmission of the virus is important if we want safely open schools, for example, “has settled.