digest
Short Summary
Main recommendation: The video gives an informational update on the emerging COVID sub-variant BA.2.75 ("Centaurus"), noting that Dr. Hansen says reinfection risk remains very high while BA.4 and BA.5 circulate. The video explains that BA.2.75 is spreading quickly, mostly in India, has been found in at least 10 other countries including the United States, and was classified by the WHO as a variant of concern on July 7th.
Key Points
- BA.2.75 is an Omicron sub-variant, derived from BA.2 but developed independently, and carries 36 mutations in its spike protein, which the video says is the most heavily mutated protein in the Omicron family.
- The video says BA.4 and BA.5 can reinfect people with prior COVID infection, including prior Omicron infection, regardless of vaccination status, and that BA.5 was about 15-fold more resistant to the monoclonal antibodies Evusheld and Sotrovimab than earlier variants.
- BA.5 appears to reach the lungs more often than Omicron, which the speaker links to the phlegm-heavy coughing seen in recent infections, making it possibly more Delta-like.
- A preprint study found Regen-COV, Evusheld, and Tixagevimab showed no antiviral effect against BA.2, BA.4, and BA.5, but appeared effective against BA.2.75, suggesting these antibodies could treat or prevent BA.2.75 infection.
- Associated lineages BA.2.74 and BA.2.76 are reportedly circulating in India as well, so more variants are expected.
Details Worth Noting
- Concrete instructions: The video gives no specific step-by-step actions for patients. The video notes a preprint suggests Regen-COV, Evusheld, and Tixagevimab could potentially be used against BA.2.75, mentions an updated bivalent vaccine targeting BA.4, BA.5, and BA.2.75 is expected in fall or winter, and states the risk of infection or reinfection remains very high, without giving direct patient instructions.
- The receptor binding domains, where the unique BA.2.75 mutations sit, are typical targets for neutralizing antibodies, so mutations there raise the chance that antibodies from vaccines, prior infection, or monoclonal treatments become less effective.
- Some mutations also increase transmissibility by promoting better binding to the ACE2 protein on human cells.
- The speaker describes the situation as a cat-and-mouse game between the immune system and continually mutating variants, requiring ongoing vaccine adaptation.
- The preprint findings were preliminary and had not been peer reviewed at the time of the video.
Bottom Line
COVID is not going away soon, and BA.2.75 joins BA.4 and BA.5 as a highly transmissible, antibody-evading threat, so infection and reinfection risk stays high while updated vaccines are developed.
