pandemic
omicron, and then? Researchers speculate about new mutants
A SARS-CoV-2 coronavirus isolated from a patient in the United States. Photo: Niaid-Rml/ZUMA Wire/dpa
© dpa-infocom GmbH
Alpha, beta, gamma, delta and omicron – at the moment the WHO lists these coronavirus variants as causing concern. But the pathogen will continue to change. A look into the crystal ball.
The Sars-CoV-2 coronavirus is likely to develop sooner or later – new variants may arise.
However, one can only speculate about their properties, said the President of the Society for Virology, Ralf Bartenschlager, to the German Press Agency. “But experience shows that pathogenicity usually decreases as a virus adapts to its host.” Pathogenicity means the ability to cause disease. “This does not mean that this adapted virus no longer causes disease, but it is usually less pathogenic.” The new variant Omikron is spreading faster in Germany than Delta, but according to researchers it causes milder illnesses on average.
General statements not possible
Richard Neher from the University of Basel emphasizes that there is no direct connection between the severity of the disease and transmissibility. It is also not possible to make general statements about the evolution of contagiousness.
It is considered quite likely that the corona virus will continue to develop after the alpha, beta, gamma, delta and omicron mutations known to date and classified as worrying by the World Health Organization. At least in the long term, this is quite possible, explained Bartenschlager. The virus will certainly be endemic and will “remain preserved” for us.
The main selection pressure that new Sars-CoV-2 variants are now subject to is the spread efficiency in a largely immune population, explained Klaus Überla from the Virological Institute at the University Hospital Erlangen. This means: In order to survive, the virus must find ways to escape the infection protection of its hosts – i.e. humans. This protection arises both through vaccination and as a result of infection. Genetic changes, for example in the so-called spike protein of the virus, can result in new forms. It is to be expected that “further so-called immune escape variants will emerge.”
Immune escape might offer some protection
A stronger immune escape ability could possibly also play a role in the spread of the omicron subvariant BA.2. “Because it can be observed in different countries that the proportion of BA.2 is increasing, it is assumed that BA.2 has an advantage in terms of transferability compared to BA.1,” said Sandra Ciesek, Director of the Institute for Medical Virology at Frankfurter University clinic, at the request of the dpa. In addition to a higher transmissibility, a stronger immune escape could lead to more and more people becoming infected with BA.2, explained Ciesek.
Immune escape means that a previous infection or vaccination protects less well against the pathogen. Nevertheless, it is possible that they offer some protection against serious illnesses.
Neher also thinks it is conceivable that the Delta variant will come back. “Delta is a highly contagious variant that after some time, when immunity has waned, could have an advantage over Omicron again,” he said in an interview published by the University of Basel. However, a new variant with unknown properties could also arise. “So we have to continue to monitor the development and emergence of new variants closely so that we can discover new variants at an early stage and understand their properties and not slip into a new wave unprepared.”
Whether the new virus variants are more dangerous or harmless cannot be reliably predicted, even in the opinion of Überla. “Distribution efficiency in the population and “danger” for the infected are different properties of viruses that can develop independently of each other,” he said.