Coronavirus may evolve into more deadly strains, experts warn

The opinions of experts, warning against too optimistic views on the evolution of covid, The Guardian writes.

Those who argue that viruses become less deadly over time often think of the flu. The viruses that led to the Spanish flu pandemic in 1918 and the swine flu pandemic in 2009 have indeed become less dangerous over time. However, many others, such as Ebola, only became more deadly over time. “It is a delusion to think that all viruses or pathogens are getting softer. If the virus retains the ability to transmit and cause outbreaks, it takes advantage of it, ”explains David Robertson, head of the department of viral genomics and bioinformatics at the Center for Viral Research at the University of Glasgow.

The virus always strives to create as many copies of itself as possible and spread as widely as possible. If the carriers manage to transmit the virus before he kills them, he uses this opportunity. This is exactly the case with SARS-CoV-2: it does not kill people during its most infectious period, they usually die two to three weeks after infection. Therefore, the virus will continue to spread and kill, if it does not evolve into a strain that will lead to such a serious illness that its carriers will not be able to communicate with others while they are infectious.

In terms of disease mildness, omicron does appear to cause less severe disease than the alpha and delta strains. However, both of these variants were heavier than the original Wuhan strain. It is important to remember that all strains evolved independently of each other: the omicron did not evolve from the delta, and that from the alpha. “If this model persists, then in six months there will be a new strain, and it could be worse,” says Robertson. "It's important not to expect the omicron to inevitably be the end of SARS-CoV-2 evolution".

There is a possibility that omicron is so transmissible that it will supplant other strains. However, a few months ago, the same was said about the delta. In addition, the omicron is likely to change. “Since the omicron infects so many people, it becomes increasingly difficult for it to spread in its original form. This creates space for the virus to mutate, which makes it easier to evade the immune response”, - says Robertson.

Well, as for the endemicity of the coronavirus, that is, turning it into a permanent disease that can be kept under control, its prospects also do not facilitate the situation. “Smallpox was endemic, polio was endemic, malaria was endemic”, - says Stephen Griffin, professor of virology at the University of Leeds. - Measles and mumps are also endemic. "Endemic" does not mean that the disease becomes harmless".

The likelihood that the virus will become less lethal increases with vaccination, experts say: the fewer infected, the less the virus has a chance to evolve. However, with the current number of unvaccinated people, this prospect seems very distant.