Omicron variants overcome some treatments

from him Appearance ofthe Omicron variant (B.1.1.529) showed a high ability to avoid the equation by antibody Because of the many mutations it carries protein S. The latter was gradually replaced by BA2, responsible for the sixth mysterious The epidemic last April, then by BA5 that feeds the current wave – 7e – which continues to grow. How well do BA4 and BA5 evade antibodies? Researchers have answers to this question.

Demilitarized antibodies against Omicron BA4 and BA5 variants

BA2, BA4 and BA5 contain mutations in their S protein that were absent in BA1, and this is one reason for their epidemiological success. Among them, F486V gives these variants a resistance Class 1 and 2 neutralizing antibodies, according to A study recently published in temper nature. Class 1 neutralizing antibodies only bind to RBD in “open” configuration, and those of Class 2 in open or closed RBD. This mutation reduces the virus’s affinity for its receptors – a problem that has been resolved by the presence of another mutation, R493Q, which restores the lost affinity.

in Another studyGerman researchers tested the neutralizing abilities of vaccine antibodies after three doses of Pfizer : The neutralizing power of antibodies is eight times lower with respect to BA4 and BA5 than that observed with B.1.1.529. Therapeutic antibodies are a complementary treatment for Vaccines Anti-Covid and many of the licensed preparations are already losing efficacy against BA4/5.

Sotrovimab (trade name Xevudy), which is active against BA1, is significantly less effective against BA2 and BA4/5. Cilgavimab (trade name Evusheld) is effective against all Omicron sub variants except BA.1. Only bebtelovimab I got Emergency use authorization from the Food and Drug Administration In February 2022, but not available in Europe, it is an effective treatment against all types of the Omicron family.

While summer will be marked as Covid, the Respect the barrier gestures More important than ever. If symptoms appear with a test detect positive for COVID-19Isolation is required. It is highly recommended to wear a mask in closed, crowded places and on public transportation.

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