The vaccination drive in the US is about to begin a new phase, after The Centres for Disease Control and Prevention endorsed booster shots for millions of older or otherwise vulnerable Americans.
CDC Director Dr. Rochelle Walensky signed off on a series of recommendations from a panel of advisers late Thursday. The advisers said boosters should be offered to people 65 and older, nursing home residents and those aged 50 to 64 who have underlying health problems. The extra dose would be given once they are at least six months past their last Pfizer shot.
Walensky made one recommendation that the panel had rejected.
The panel had voted against saying that people can get a booster if they are 18 to 64 years old and are health-care workers or have another job that puts them at increased risk of being exposed to the virus.
Walensky disagreed and issued a statement saying she had restored the recommendation.
"As CDC Director, it is my job to recognise where our actions can have the greatest impact," Walensky said in a statement late Thursday night. "At CDC, we are tasked with analysing complex, often imperfect data to make concrete recommendations that optimise health. In a pandemic, even with uncertainty, we must take actions that we anticipate will do the greatest good."
Experts say getting the unvaccinated their first shots remains the top priority, and the panel wrestled with whether the booster debate was distracting from that goal.
All three of the COVID-19 vaccines used in the US are still highly protective against severe illness, hospitalisation and death, even with the spread of the extra-contagious delta variant. But only about 182 million Americans are fully vaccinated, or just 55 per cent of the population.
"We can give boosters to people, but that's not really the answer to this pandemic," said Dr. Helen Keipp Talbot of Vanderbilt University. "Hospitals are full because people are not vaccinated. We are declining care to people who deserve care because we are full of unvaccinated COVID-positive patients."
The booster plan marks an important shift in the nation's vaccination drive. Britain and Israel are already giving a third round of shots over strong objections from the World Health Organisation that poor countries don't have enough for their initial doses.
The CDC advisers expressed concern over the millions of Americans who received Moderna or Johnson & Johnson shots early in the vaccine rollout. The government still hasn't considered boosters for those brands and has no data on whether it is safe or effective to mix-and-match and give those people a Pfizer shot.
The US has already authorised third doses of the Pfizer and Moderna vaccines for certain people with weakened immune systems, such as cancer patients and transplant recipients. Other Americans, healthy or not, have managed to get boosters, in some cases simply by asking.
Australian Associated Press