Some 60 million people in the United States are now eligible for a Pfizer booster shot against Covid-19, President Joe Biden said on Friday as a regulatory marathon laying bare divisions within the scientific community on the issue came to a close.
In the end, US health authorities have recommended boosters for three categories of people: those 65 and older, those 18-64 with an underlying medical condition such as diabetes or obesity, and those who are especially exposed to the virus because of their work or where they live.
The last, at-risk group is large and includes teachers, grocery store employees, health care workers, prisoners and people living in homeless shelters.
A total of 20 million people got their second Pfizer shot long enough ago -- at least six months -- to qualify now for a booster, Biden said.
"Go get the booster," he said in a remarks at the White House.
"I'll be getting my booster shot," the 78-year-old president added, "as soon as I can."
Biden said people who have received Moderna or Johnson & Johnson vaccinations could get booster shots once studies have been completed and he expected that all Americans would be eligible "in the near term."
Some immunocompromised people in the United States have been eligible to receive a third dose of Pfizer or Moderna vaccine since early August.
Biden had wanted to launch a mass campaign of Pfizer and Moderna booster shots this week for all Americans.
But the move was put on hold by the US health authorities. Moderna did not submit the necessary data in time and experts were divided about what to do regarding Pfizer.
The Centers for Disease Control and Prevention (CDC) on Friday overruled its own panel of health experts to back Pfizer booster shots for individuals at high risk of exposure because of their jobs.
The greatest good
CDC director Rochelle Walensky said the agency had to act on "complex, often imperfect data" for the greater good of public health.
"In a pandemic, even with uncertainty, we must take actions that we anticipate will do the greatest good," Walensky said in a statement.
The CDC also backed the panel's recommendation of booster shots for over-65s and some with underlying medical conditions.
The decision came after the US Food and Drug Administration (FDA) approved Pfizer booster shots for a broader swathe of the American public.
A day before the CDC recommendation, its expert had committee voted against offering booster shots to workers in the higher risk category, adding to confusion around the campaign.
The hours-long debate left several experts torn, as the scientific community has so far failed to reach consensus on whether a coronavirus vaccine booster shot is necessary at this time.
Some experts have concerns about the lack of data on the efficacy and safety of adding another shot to the Pfizer vaccine regimen.
The original two doses are still proving successful at keeping the vast majority of their recipients out of the hospital with coronavirus, they say.
But data does suggest that the vaccine's efficacy against infection does significantly decline in older people over time.