KAZAN, November 17. /TASS/. Mutational changes are inherent for viruses which is supported by the example of the SARS-CoV-2 virus with the number of known variations since the beginning of its spread worldwide reaching 500, Director of Kazan Federal University’s Research Clinical Center for Precision and Regenerative Medicine Albert Rizvanov who heads a research group of developers of a test system and a vaccine against the coronavirus told TASS on Tuesday.
"To date, about 500 various mutations of the novel coronavirus are known, this is a normal manifestation, since all live organisms mutate and evolve. Viruses mutate especially rapidly because they have a very primitive genetic apparatus. <…> More often the mutations weaken the virus making it less deadly. However, at the same time it may become more contagious. At the moment, all the coronavirus mutations described in research articles insignificantly influence the properties of the virus causing COVID-19," the scientist said.
Earlier on Tuesday, Head of the Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing Anna Popova reported on changes in the virus circulating in Siberia. At the same time she noted that these changes did not make it more dangerous.
As Rizvanov explained to TASS, the mutation occurs in the process of self-replication of the coronavirus. A polymerase protein, copying a viral genome, makes a lot of mistakes which cause the emergence of new variants of the virus. Frequently numerous mutant variants of the virus may be present in the system of the same person, the scientist added.
The expert also added that to date, scientists do not have valid data that the coronavirus mutations increase mortality or cause serious forms of the disease. However, in rare cases the mutations indeed can make the viruses stronger. In the case of the SARS-CoV-2 virus it is the D614G variety with the mutation in the spike protein. The researchers think that this coronavirus version is more contagious.
New vaccine not needed
According to the scientist, the current information on the mutations allows to conclude that vaccines against the coronavirus infection being developed worldwide are capable of fighting the mutated virus. "They should work against the mutant variants of the virus as well since they are based on the full spike protein. This helps develop a comprehensive immunity which will cope with the coronavirus even if some of its spike protein mutates. The residual antibodies against other sequences of the spike protein should be sufficient to neutralize the virus," the interlocutor told TASS.
The vaccines may require additional work only if the coronavirus strains begin to significantly differ from the initial one. However, to date, no preconditions for this have been observed since the coronavirus due to the absence of pharmaceuticals directed against it does not experience "selective pressure" stimulating its evolution and making it resistant to therapy, the scientist noted.
In his opinion, the coronavirus mutations signify that it is undergoing a period of active selection. "Evolutionally viruses become more contagious but less lethal. Thus, a virus fulfills its built-in propagation program: in order to do so, it is necessary to infect successfully, yet not kill, its host. This is precisely why the existing "safe" viruses took on these properties - they learned to cause the least harm to humans for their own survival and they are activated only when the immune system is disrupted. If one talks about the coronavirus, then, most likely, it will also become a little bit more contagious and a little bit less lethal," the researcher thinks.
He specified that for substantial evolutionary changes the viruses need "hundreds or even millions of years" so one shouldn’t expect cardinal changes in the coronavirus during one season.