The scientists urge caution: it is premature to let our guard down on COVID-19.
The wind of optimism that has been blowing due to the Omicron variant might be unjustified. Some believed that Omicron signals the beginning of the end of the pandemic, as it leads to less severe symptoms, tending not to attack the lungs. Consequently, European countries are lifting many COVID-19-related restrictions.
However, the paper points out that viruses evolve to maximise their transmissibility and this sometimes may be accompanied by an increase in their pathogenicity. The notion that viruses will evolve to be less virulent to spare their hosts is one of the most persistent myths surrounding pathogen evolution, according to the scientists.
With the Omicron variant showing 50 nucleic acid changes compared to the original Wuhan strain, SARS-CoV-2 proved to have a high ability to mutate over a relatively short period.
The unpredictable antigenic evolution of SARS-CoV-2 will lead to new variants. These may escape our immunity and so could be better able to re-infect individuals, and potentially be more severe.
Therefore, there is no guarantee that future variants will be milder, the scientists warn.
They advise in their paper that decisions for lifting anti-epidemic measures need to be prudent and accompanied by close surveillance of the levels of transmission of the virus and rates of hospitalisation.
- Data di pubblicazione
- 24 marzo 2022
- Centro comune di ricerca