Covid-19: New branch of Omicron BA.4.6 escapes protection from Evusheld antibody, study finds – zimo news


BA.4.6 is an offshoot of the BA.4 subvariant of the Omicron coronavirus variant. Only a few mutations distinguish it from its predecessor, but it is slowly gaining ground in the United States, even compared to BA.5, which continues to dominate transmission.

BA.4.6 is now reported to be responsible for around 7% to 10% of new Covid-19 infections data From the U.S. Centers for Disease Control and Prevention. It’s especially prevalent in the Midwest, where it accounts for about 18 percent of new infections.

Evusheld is a combination of two long-lasting, laboratory-made antibodies made by AstraZeneca. Given every six months, it protects against Covid-19 in people who may not be adequately protected by the vaccine because their immune systems cannot respond to it effectively. The CDC estimates that about 7 million Americans could benefit from Evusheld’s protection.

This life-saving therapy has worked well against a variant of the novel coronavirus. But in the new test, David Ho, Ph.D., a professor of microbiology and immunology at Columbia University, found that while this sub-variant doesn’t seem to bind to our cells any more readily than others, it appears to evade certain cells. ability. Neutralizing antibodies, including Evusheld’s antibodies.

“We found that this antibody combination no longer works against this new variant, which is the only antibody combination approved to prevent Covid-19,” Ho told CNN.

Ho and his team have worked throughout the pandemic to rapidly characterize new variants to help the United States refine its treatment strategies.

His latest research has been shared as preprintbefore peer review.

Ho said he also sent his results to the National Institutes of Health and the U.S. Food and Drug Administration.

In a statement, the FDA said it “is working with sponsors of all currently licensed treatments to evaluate activity against any SARS-CoV-2 global variant of interest and is committed to communicating with the public, as We will find out more”.

AstraZeneca said Evusheld’s antibodies work together, and testing them individually may not reflect real-world therapeutic performance.

“There is limited relevance to studies evaluating Evusheld component antibodies alone or in combination or attempting to reconstitute versions of tixagevimab and cilgavimab with true Evusheld. Data from individual Evusheld antibodies do not represent a synergistic effect of the combination administered in the Evusheld label. A spokesperson said in a statement. The antibody, which was reconstituted in the lab based on publicly available information, is not an exact replica of Evusheld, the report said.

Ho said he tested the antibody combination and was confident in his results.He noted that his team’s findings are related to similar tests Made by Chinese scientists.

Meanwhile, immunocompromised people need to know that Evusheld may not be as protective as it once was, Ho said.

“Just know that BA.4.6 will be resilient and progress on BA.5. So generally immunocompromised people should be more cautious,” he said.

Ho said that based on his research, only one monoclonal antibody — bebtelovimab — continued to be effective against the circulating variant.

“Now we’re basically just left with antibodies,” he said. “There’s nothing else left.»

He said the FDA has been very focused on updating Covid-19 vaccines, but he is concerned that it is not continuing to keep antibody treatments up to date.

“There are millions of people with compromised immune systems who have no choice right now,” he said.

Source link


Please enter your comment!
Please enter your name here