A new sub-variant of the novel coronavirus known as XBB made a dramatic appearance in Singapore. The number of new COVID-19 cases more than doubled in a single day, from 4,700 on Monday to 11,700 on Tuesday, and XBB is almost certainly to blame. The same sub-variant has recently appeared in Hong Kong.
XBB is a highly mutated descendant of the SARS-CoV-2 virus’s Omicron variant, which caused a record wave of infections around a year ago. It is the virus’s worst form to date in many ways. It spreads faster than any previous variant or sub-variant. It also avoids the antibodies used in monoclonal therapies, potentially rendering a whole class of COVID treatments ineffective.
“It is likely the most immune-evasive and poses problems for current monoclonal antibody-based treatments and prevention strategy,” Amesh Adalja, a public-health expert at the Johns Hopkins Center for Health Security, told Yahoo.
The bad news is that The good news is that the new “bivalent” vaccine boosters from Pfizer and Moderna appear to be effective against XBB, despite the fact that the original vaccines are less effective. They will not prevent all infections and reinfections, but they will significantly reduce the risk of severe infection, which could result in hospitalization or death. “Even with immune-evasive variants, vaccine protection against what matters most—severe disease—remains intact,” Adalja said.
As the novel coronavirus evolves to become more contagious and resistant to certain drugs, staying up to date on boosters is “the most impactful thing you can do in preparation for what might come,” according to Peter Hotez, a vaccine development expert at Baylor College.
XBB was discovered by scientists in August. It’s one of several major sub-variants that have evolved from the basic Omicron variant, piling on more and more mutations to key parts of the virus, particularly the spike protein, which helps the virus latch onto and infect our cells.
The worst situation can be avoided. Natural antibodies from previous infections continue to be the best and most durable antibodies. They do not last indefinitely. However, while they can last for a few months or even a year, the chances of contracting COVID are extremely low.