BA.2.75.2 would resist most treatments against Covid-19 because antibodies would not be effective enough to fight this sub-variant of Omicron. Explanations.
- According to Santé Publique France, there are 100% of Omicron among the viruses sequenced over the last seven days, as of September 26, 2022.
- As of October 13, 2022, the incidence rate was 580.5 according to Santé Publique France.
As of October 16, 2022, 41,973 people have tested positive for Covid-19 for the first time in more than 60 days in the past 24 hours, according to Public Health France. Of these, almost all were contaminated with the Omicron variant.
Omicron BA.2.75.2 subvariant is antibody resistant
Omicron is a variant of Covid-19 which also has sub-variants: BA.1, BA.2, BA.3, BA.4 and BA.5. Some have additional mutations… This is the case of BA.2.75.2, which seems particularly worrying.
Indeed, according to a new study published in the journal The Lancet Infectious Diseases, the BA.2.75.2 subvariant would evade antibodies. Thus, the vast majority of currently available treatments would not be effective against it. There would therefore be a very high risk of infections for the coming winter.
A single effective treatment against the BA.2.75.2 subvariant
To reach this conclusion, the researchers analyzed blood samples from 75 people taken at different times: November 2021 (before the emergence of Omicron), April 2022 and late August-early September, when BA.5 was widely majority among people positive for Covid-19.
Results: Only a sixth of these samples showed antibodies effective against the BA.2.75.2 subvariant. On the other hand, they were effective against BA.5. “BA.2.75.2 exhibited much greater resistance than the variants we previously investigated, largely due to two mutations“, details Ben Murrell, one of the authors in a Press release. According to researchers, there is only one monoclonal antibody therapy which works against BA.2.75.2: bebtelovimab.
Unknown on vaccine efficacy for subvariant BA.2.75.2
But, according to theNational Agency for the Safety of Medicines and Health Products (Ansm), the temporary authorization for use “bamlanivimab (alone), which was no longer used since the availability of antibody combinations, has, for its part, been definitively closed”. In a notice published on July 19the scientific council asked the government “to make every effort to ensure that bebtelovimab, the only monoclonal antibody currently active on BA.5, is available as soon as possible in France”.
Another question raised by this study: the efficacy of vaccines for the BA.2.75.2 subvariant? Difficult to answer for the moment… But the researchers hope that this will be the case for new vaccinesknown as bivalent vaccines, which protect against the original strain of the Covid-19 virus but also against certain sub-variants of Omicron. “We expect them to be effective, but we do not yet know to what extentconcludes Ben Murrell. We now know that there are emerging variants with similar mutations that will likely end up being the majority in the near future.concludes Ben Murrell. We should expect infections to increase this winter“.
