What will happen with COVID-19?

Three years since the start of the pandemic, SARS-CoV-2 faces the immunity that humans built up through vaccines and countless infections.

SARS-CoV-2 is still evolving

'We can say with certainty that something is coming,' says Cornelius Roemer, a scholar of viral evolution at the University of Basel (Switzerland). The big question we are all asking is whether the virus' new responses will also cause many hospitalisations and deaths. 'Not surprisingly, we are seeing changes that once again help the virus evade immune responses,' says molecular epidemiologist Emma Hodcroft of the University of Bern (Switzerland).

The variants that seem poised to drive the latest comeback are all sub-variants of Omicron. One of them, BA.2.75.2, seems to be spreading rapidly in India, Singapore and parts of Europe. Other new immune strains have evolved from BA.5, including BQ.1.1, detected in several countries around the world. Researchers in China and Sweden have found that the spike protein of BA.2.75.2 can effectively evade almost all monoclonal antibodies used to treat COVID-19, suggesting that these therapies may become ineffective.

Most recent studies on new SARS-CoV-2 variants

In a preprint published on 19 September 2022, Ben Murrell, an immunologist at the Karolinska Institute, reported that serum samples from 18 blood donors in Stockholm, where vaccination rates are high and previous infections are widespread, were much less effective in neutralising the BA.2.75.2 variant than BA.5. 'This is the most resistant variant we have ever evaluated,' says virologist Daniel Sheward, Karolinska Institute.

Immunologist Yunlong Richard Cao, Peking University, obtained similar results for BA.2.75.2. The team found that BQ.1.1 had an equally surprising ability to evade antibodies. In their preprint, updated on 23 September 2022, Cao and colleagues also report that the new variants do not appear to have lost any ability to bind tightly to the receptor on human cells that the virus uses to infect them, meaning that the infectivity of the variants has probably not diminished.

Infections with these new variants trigger proportionally more wrong types of antibodies, those that bind tightly to the virus but do not reduce its ability to infect cells.

All this could presage a new mass wave, 'The virus is still evolving rapidly,' Cao comments. However, how brutal a possible new wave of the coronavirus might be will become clear once more people are infected with the new strains. The immune response against SARS-CoV-2, following infections and vaccinations, will certainly mitigate the severity of these expected new waves, however.

  1. Vogel G. Big COVID-19 waves may be coming, new Omicron strains suggest. Science. Sep 2022. doi: 10.1126/science.adf0790
  2. Omicron sublineage BA.2.75.2 exhibits extensive escape from neutralising antibodies. Daniel J. Sheward, Changil Kim, Julian Fischbach, Sandra Muschiol, Roy A. Ehling, Niklas K. Björkström, Gunilla B. Karlsson Hedestam, Sai T. Reddy, Jan Albert, Thomas P. Peacock, Ben Murrell. bioRxiv 2022.09.16.508299; doi: https://doi.org/10.1101/2022.09.16.508299 [This article is a preprint and has not been certified by peer review]
  3. Imprinted SARS-CoV-2 humoral immunity induces converging Omicron RBD evolution. Yunlong Cao, Fanchong Jian, Jing Wang, Yuanling Yu, Weiliang Song, Ayijiang Yisimayi, Jing Wang, Ran An, Na Zhang, Yao Wang, Peng Wang, Lijuan Zhao, Haiyan Sun, Lingling Yu, Sijie Yang, Xiao Niu, Tianhe Xiao, Qingqing Gu, Fei Shao, Xiaohua Hao, Yanli Xu, Ronghua Jin, Youchun Wang, Xiaoliang Sunney Xie. bioRxiv 2022.09.15.507787; doi: https://doi.org/10.1101/2022.09.15.507787 [This article is a preprint and has not been certified by peer review]