us The U.S. Is About to Make a Big Gamble on Our Next COVID Winter In a recent advisory meeting convened by the FDA, Peter Marks, the director of the agency’s Center of Biologics Evaluation and Research, acknowledged the “very compressed time frame” in which experts will need to finalize the inoculation’s ingredients—probably, he said, by the end of June. Which is, for the record, right around the corner. A big choice is looming. And whatever version of the virus that scientists select for America’s next jab is “probably going to be the wrong one,” says Allie Greaney, who studies the push and pull between viruses and the immune system at the University of Washington and the Fred Hutchinson Cancer Center. In recent months, though, the virus appears to have taken a different tack. Since the end of 2021, nearly everything’s been coming up Omicron. From BA.1 (a.k.a. Omicron classic) to BA.2, and now the rising BA.2.12.1, BA.4, and BA.5, the last few viral successions have all occurred within the Omicron clan. So our next move might seem obvious: counter with an Omicron-centric vaccine, a switch some experts have been favoring for months. On that front, Moderna and Pfizer might soon deliver. The two vaccine makers have each been testing, among other options, bespoke BA.1 versions of their shots that they say could be ready within the next few months, just in time for a pre-winter inoculation push. “We plan to have a data readout soon,” Jerica Pitts, a spokesperson for Pfizer, wrote in an email. Perhaps the bigger worry is whether BA.1 will end up being a terrible teacher when deployed as an unvaccinated person’s starter shot. The variant’s bizarro-looking spike, so unlike any that came before it, is such an outlier that it may fail to show an unsavvy immune system how to recognize other morphs of SARS-CoV-2. That’s not a problem if the future of the virus stays hooked on Omicron. But should it be booted by another variant more resembling Alpha, Delta, or something else, bodies schooled on BA.1 alone might be ill-prepared. Pfizer, which is testing a triple-Omicron series in a group of previously unjabbed people, could produce data to the contrary. Absent those, a premature pivot to Omicron might bias immune systems toward the wrong track.

omicron Pfizer’s Covid Vaccine Protection Against Omicron Fades Just Weeks After Second And Third Doses, Study Finds Immunity against the omicron coronavirus variant fades rapidly after a second and third dose of Pfizer and BioNTech’s Covid-19 vaccine, according to peer reviewed research published in JAMA Network Open on Friday, a finding that could support rolling out additional booster shots to vulnerable people as the variant drives an uptick in new cases across the country. Levels of omicron-specific “neutralizing” antibodies—which can target the virus and stop it from replicating—decline rapidly after a second and third dose of Pfizer’s shot, according to the Danish study of 128 people who had received two or three doses. Antibody levels, which are associated with protection against infection and disease, fell within weeks of getting the shots and were much lower than the level of antibodies specific to the original and delta coronavirus variants, the researchers said. Compared to original and delta variants, the proportion of omicron-specific antibodies detected in participants’ blood dropped “rapidly” from 76% four weeks after the second shot to 53% at weeks eight to 10 and 19% at weeks 12 to 14, the researchers found. Omicron-specific antibody levels increased after the third dose—nearly 21-fold at week three and nearly 8-fold at week four, compared to four weeks after the second dose—and the shot generated a detectable response in most people for at least eight weeks, the researchers said. However, antibody levels started to drop as early as three weeks after the booster shot, falling 4.9-fold for the original variant, 5.6-fold for delta and 5.4-fold for omicron between weeks three and eight. The “transient” antibody response after doses two and three mean additional booster shots might be needed to combat the variant, particularly among older people, the researchers said.