WASHINGTON, United States -- The Centers for Disease Control and Prevention (CDC) on Friday overruled its own panel of health experts to back Pfizer Covid vaccine booster shots for individuals at high risk of exposure because of their jobs.
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," she said in a statement.
The CDC also backed the panel's recommendation of booster shots for over-65s and some with underlying medical conditions.
"I believe we can best serve the nation's public health needs by providing booster doses for the elderly, those in long-term care facilities, people with underlying medical conditions, and for adults at high risk of disease from occupational and institutional exposures," Walensky said.
The recommendations are only for people who had their vaccine doses at least six months ago.
That means about 26 million people in the United States are eligible for a third jab, the CDC said, including about 13 million people aged 65 and older.
The decision comes after Food and Drug Administration (FDA) on Wednesday approved Pfizer booster shots for a broader swathe of the American public.
Those workers eligible because of a higher risk of Covid exposure include teachers, grocery store employees, health care workers and prison inmates.
A day before the CDC recommendation, its expert 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.
The Biden administration had originally planned on a mass campaign to administer third doses to all recipients of either the Pfizer or Moderna vaccines, starting September 20.
But experts at the FDA rejected that plan last week.