omicron XBB.1.5 is immune evasive and binds better to cells

The Covid omicron XBB.1.5 variant is rapidly gaining ground in the United States. This is because they are more immune evasive and appear to be more effective at binding to cells than related subvariants.

XBB.1.5 now accounts for about 41% of new cases nationwide, with prevalence nearly doubling in the past week, according to data released Friday by the Centers for Disease Control and Prevention. This subvariant has more than doubled his share of weekly cases through December 24th. Over the past week, the prevalence has almost doubled from 21.7%.

Scientists and public health officials have been closely monitoring the XBB subvariant family for months. That’s because the strain has a number of mutations that can make Covid-19 vaccines, including the Omicron booster, less effective, and even cause breakthrough infections.

XBB was first identified in India in August. There, it will soon become dominant, and not just in Singapore. It has since evolved into a family of subvariants such as XBB.1 and XBB.1.5.

Virologist Andrew Pekos of Johns Hopkins University said XBB.1.5 differs from its family because it has additional mutations that bind it better to cells.

“Viruses need to bind tightly to cells in order to enter more efficiently, and that could help the virus to infect people a little more efficiently.

Yunlong Richard Cao, a scientist and assistant professor at Peking University, shared data on Twitter showing that XBB.1.5 not only evades protective antibodies as effectively as the XBB.1 variant, but also has higher immune evasion. Announced. cells through key receptors.

Scientist at Columbia University, In a study published earlier this month in the journal Cellwarned that an increase in subvariants such as XBB “could further undermine the efficacy of current COVID-19 vaccines, resulting in a surge in breakthrough infections and reinfections.” did.

The XBB variant is also resistant to Evusheld. Evusheld is an antibody cocktail that many people with weak immune systems rely on for protection against her Covid infection because they do not show strong reactions to vaccines.

The scientists described the XBB subvariant’s resistance to antibodies from vaccination and infection as “alarming.” Scientists have discovered that the XBB subvariant is even more effective at fending off protection from Omicron boosters than the BQ subvariant, which also has a higher ability to evade immunity.

Dr. David Ho, author of the Columbia study, agreed with other scientists that XBB.1.5 probably binds better to cells than its close relatives, and therefore has a growth advantage. Ho also said that XBB.1.5 is almost as immune-evasive as He XBB and He XBB.1. XBB and XBB.1 were so far the two most resistant subvariants to protective antibodies from infection and vaccination.

Dr. Anthony Fauci, who is stepping down as the White House’s chief medical adviser, has previously said that the XBB variant reduces the protection boosters provide against infection “many fold.”

“You can expect some protection, but it’s not optimal,” Fauci said at a White House press conference in November.

Fauci said he was encouraged by the case of Singapore, where infections from XBB surged significantly, but did not increase hospitalizations at the same rate. Pekosz said XBB.1.5, combined with holiday travel, could lead to an increase in cases in the United States, but said the boosters appeared to prevent serious illness.

“It looks like a vaccine, a bivalent booster that provides continued protection against hospitalizations with these variants,” said Pekosz. “There is a great emphasis on the need to obtain boosters for particularly vulnerable populations to provide continued protection from severe disease with these new variants.”

US health officials have repeatedly called for good health care, especially for older people. Up-to-date on vaccines and being treated with the antiviral drug paxlovid if they have a breakthrough infection.