BOOSTER CLUB — When the mRNA Covid vaccines became broadly available last year, Peter Hotez predicted that two shots wouldn't be enough. The two shots were being administered between three to four weeks apart — too close together to offer durable protection, Hotez, dean for the National School of Tropical Medicine at the Baylor College of Medicine, told Nightly last year. A third shot, offered months after the second one, would be the magic formula, he predicted (while cautioning that it was just conjecture). "It's three and done." Today, the CDC recommended a fourth Covid shot — a second booster — to those 12 and older who are immunocompromised and people who are 50 and over. More than a year into the Covid vaccine rollout, researchers and the Biden administration don't know when the Covid booster shots will end and whether we will need to staple a second page onto our vaccine cards. "We're in uncharted territory," Hotez said. What's clear is that the ability of the Moderna and Pfizer vaccines to keep people out of hospitals seems to wane a bit with time. CDC data shows that four months after a third Covid vaccine dose , protection against hospitalizations decreased to 78 percent from 91 percent two months after the shot, and protection against emergency room visits decreased to 66 percent from 87 percent. It's less clear, however, whether that waning effectiveness is caused by new Covid variants or the technology itself — or some combination of both. The evidence for a fourth shot is thin. It comes largely from one, not-yet peer reviewed, Israeli study . In it, the death rate for people who got a fourth dose during an Omicron surge (92 deaths out of 328,597 people) was more than three times lower than the death rate for those who got a third dose (232 deaths out of 234,868 people). Both death rates are dramatically lower than rates for people who got no shots at all. During the Omicron surge in January, the death rate for unvaccinated Americans was about nine to 10 times higher than those who received two shots, according to The New York Times. The third mRNA Covid shot boosted immunity well above two shots, and the fourth shot brings immunity back to the baseline third-shot level, said Saad Omer, the director of the Yale Institute for Global Health, in an interview with Nightly. Someone who got two Pfizer or Moderna shots last year and a third shot today would have the same protection as someone who got three shots last year and a fourth shot today. About two-thirds of fully vaccinated people — those with two mRNA shots or one J&J shot — 65 and older have received one booster in the U.S., and about 45 percent of all fully vaccinated people in the country have, according to CDC data. With BA.2, a subvariant of Omicron, becoming the dominant strain in the country, it makes sense to open up fourth doses to vulnerable people, Hotez and Omer said. Most healthy people are fairly well protected with two shots. But Black Americans in particular suffer from health inequities that have made them, as a group, more susceptible to dying from Covid, said Omer, who serves on a World Health Organization Covid working group. The 50-and-up recommendations, as opposed to just focusing on people over 65, reflects that reality, Omer said. The move could backfire, however, if a more contagious variant pops up in the fall and immunity from the fourth doses has already waned. Both scientists worry about the lack of a strategy beyond just continuous mRNA boosters with each new variant. "Right now the U.S. is operating with one technology," said Hotez, who developed a recombinant protein vaccine that's being used elsewhere in the world. "I think that is a risky proposition." The White House's Covid plan, released earlier in March, included plans to launch a universal Covid vaccine and variant-tailored vaccines within 100 days of recognizing the threat. A federal health official told Nightly that developing those vaccines "requires additional resources and funding that Congress so far has failed to appropriate." Welcome to POLITICO Nightly. Reach out with news, tips and ideas at nightly@politico.com. Or contact tonight's author at rrayasam@politico.com, or on Twitter at @RenuRayasam.
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