Now the virus is trying to find a way around our antibodies. A new subvariant, BA.4.6, is beginning to outcompete its predecessor, BA.5. Its advantages include a particular mutation to the spike protein, the part of the virus that helps it to grab onto and infect our cells.

We’ve seen this R346T mutation before. And every time it’s appeared, it’s been associated with forms of the SARS-CoV-2 pathogen with an increased ability to dodge our antibodies. A quality epidemiologists call “immune escape.”

If BA.4.6 becomes dominant, it could reverse the encouraging trend we’ve seen in most countries in recent weeks toward fewer infections, fewer hospitalizations, fewer deaths…

If there’s good news in BA.4.6’s rise, it’s that for all its worrying mutations it’s still an Omicron sublineage—and still has a lot of mutations in common with BA.5, BA.4, BA.2 and BA.1.

That means the Omicron-specific boosters that Pfizer and Moderna are developing for their messenger-RNA vaccines, and which U.S. regulators are on track to approve in coming weeks, should still work at least somewhat against BA.4.6.