Quick and stealthy "Scrabble variants" are poised to drive a winter Covid-19 surge

A flurry of new Covid-19 variants appears to be gaining traction globally, raising fears of a winter surge.   In the United States, these are BQ.1, BQ.1.1, BF.7, BA.4.6, BA.2.75 and BA.2.75.2. In other countries, the recombinant variant XBB has been rising quickly and appears to be fueling a new wave of cases in Singapore. Cases are also rising in Europe and the UK, where these variants have taken hold.   Dr. Peter Hotez, who co-directs the Center for Vaccine Development at Texas Children’s Hospital, says he thinks of them collectively as the Scrabble variants because they use letters that get high scores in the board game like Q, X and B.   As the US moves into the fall, Covid-19 cases are dropping. Normally, that would be a reason for hope that the nation could escape the surges of the past two pandemic winters. But virus experts fear that the downward trend may soon reverse itself, thanks to this gaggle of new variants.   Lumped together, the variants accounted for more than 1 in 3 new Covid-19 infections nationwide in the week ending October 15, according to the latest CDC estimates.   These variants are different from BA.4 and BA.5, but they’re descended from those viruses, the result of genetic drift. So they share many parts of their genomes with that virus.   Their changes aren’t on the scale of what happened when the original Omicron arrived on the scene in November 2021. That strain of the virus, which is now long gone, came out of genetic left field, leaving researchers and public health officials scrambling to catch up.   The bivalent booster vaccine, authorized in September, protects against the original strain of the coronavirus as well as the BA.4 and BA.5 subvariants.   “It isn’t that different from BA.5 that it would completely escape the protection that you would get from vaccine” – but more people need to get the shot, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.