• Public-health experts are sounding the alarm about a new Omicron variant dubbed XBB that is rapidly spreading across the Northeast U.S. Some studies suggest it is as different from the original Covid strain from Wuhan as the 2003 SARS virus. Should Americans be worried?
• It isn’t clear that XBB is any more lethal than other variants, but its mutations enable it to evade antibodies from prior infection and vaccines as well as existing monoclonal antibody treatments. Growing evidence also suggests that repeated vaccinations may make people more susceptible to XBB and could be fueling the virus’s rapid evolution.
• Prior to Omicron’s emergence in November 2021, there were only four variants of concern: Alpha, Beta, Delta and Gamma. Only Alpha and Delta caused surges of infections globally. But Omicron has begotten numerous descendents, many of which have popped up in different regions of the world curiously bearing some of the same mutations.

Tagged: COVID-19