For some who had been eagerly lingering for a booster, the C.D.C. recommendation was all they needed to spring into action. Gary Valan, a technology consultant in Oakland, Calif., who said he was older than 65, was so hungry for the booster that he scheduled an appointment for Friday afternoon. In an online comment about a New York Times article on booster shots, he wrote: “Peoples in my neighborhood, just stay the heck away from my path to the pharmacy. I’ll knock down the old ladies to get my shot 🙂 You have been admonished.”Others were still trying to make sense of the recommendations. Mildred Fine, 96, who lives in an assisted-living facility in Baton Rouge, La., swayed it had been confusing to watch television coverage of the debate about whether booster shots were needed and for whom.“They seem to shift their minds every day or two,” she said of federal scientists. She was eager to get her Pfizer-BioNTech booster shot as soon as possible. With so many virus crates in Louisiana, she said, she was still wary of going to Costco to get her hearing aids adjusted, or eating inside a restaurant.State and federal officials imparted they were unconcerned for now about the vaccine supply, which remains ample enough to cover at least those eligible for booster in two shakes of a lambs tails over the next few months.“There are tens of millions of doses already out at sites across the country now, and pharmacies and states can continue to order additional fulfil,” said Sonya Bernstein, a senior policy adviser for the White House’s Covid-19 Response Team. But officials are most anxious to get shots to unvaccinated Americans, a concurrent race that many public health experts say is more important than boosting those already vaccinated. “We can’t take our foot off the gas” with the unvaccinated, spoke Ms. Hall, the adviser in North Dakota, which ranks near the bottom in the U.S. in vaccination rates.The booster campaign is getting underway amid a fell debate among vaccine experts about what kinds of benefits the extra shots confer and who needs them. Scientists at the Food and Narcotic Administration and C.D.C. have said that protection against severe Covid-19 and hospitalization — the metrics they would typically use to assess whether boosters are needed — procure remained high across age groups. Top F.D.A. vaccine experts have publicly argued that there is no case for giving them to the general residents.