The US Food and Drug Administration (FDA) has authorized second Covid-19 booster doses of Pfizer or Moderna vaccines for older and immunocompromised Americans.
The coronavirus pandemic has killed more than 977,000 people in the US but case numbers have been falling. Authorities have nonetheless warned that the US could experience a surge fueled by virus subvariants or a new variant.
“Current evidence suggests some waning of protection over time against serious outcomes from Covid-19 in older and immunocompromised individuals,” said Peter Marks, director of the FDA Center for Biologics Evaluation and Research, on Tuesday.
“Based on an analysis of emerging data, a second booster dose of either the Pfizer-BioNTech or Moderna Covid-19 vaccine could help increase protection levels for these higher-risk individuals.
“Additionally, the data show that an initial booster dose is critical in helping to protect all adults from the potentially severe outcomes of Covid-19. So, those who have not received their initial booster dose are strongly encouraged to do so.”
The federal Centers for Disease Control and Prevention will now decide when and how second booster shots are offered.
According to the New York Times’ vaccine tracker, 72% of Americans aged 18 to 64 and 89% aged 65 or older are considered fully vaccinated. The percentages in those groups who have received a booster shot are 30% and 60%.
Resistance to vaccinations and other public health measures, often fueled by rightwing politicians, has been a constant feature of the US pandemic response.
The FDA said on Tuesday its emergency-use authorizations had been amended to allow for second booster doses in people older than 50 at least four months after a first booster dose. It also approved it for certain kinds of immunocompromised people, including recipients of organ transplants, where it would apply to anyone over 12 (Pfizer) or 18 (Moderna).
“The authorization of a single booster dose for other age groups with these vaccines remains unchanged,” the FDA said, adding that it would “continue to evaluate data and information as it becomes available when considering the potential use of a second booster dose in other age groups”.
In a statement, Albert Bourla, the chief executive of Pfizer, said: “While this emergency use authorization will help address a current need for some, we’re working diligently to develop an updated vaccine that not only protects against current Covid-19 strains. , but also provides more durable responses.”
Pfizer and BioNTech, its partner on the Covid virus, originally asked for the next US booster doses to be authorized for people 65 and older, in a submission citing data collected in Israel, where a second booster is authorized for many people over age 18.
The companies and the FDA did not explain why the age range had been expanded.
Scientists and officials have debated whether young and healthy people will need a fourth shot. A study of Israeli healthcare workers suggested that the fourth dose added little additional protection in the age group.
Biden administration officials have said that the US has enough doses to meet demand for another round of booster shots in older Americans, even as funding for the federal pandemic response has all but run out.
They say that unless Congress approves more spending, the government will not be likely to be able to pay for future inoculations, if needed, particularly if the vaccines need to be redesigned to target new variants.
Public weariness with pandemic regulations and official advice, meanwhile, has been deepened by confusion over changes such as that regarding second booster shots.
On Tuesday John P Moore, a professor of microbiology and immunology at Weill Cornell Medicine in New York, told the Washington Post: “I’ve been getting multiple inquiries from lay friends over the past few days: ‘What does this mean, and what should I do?’
“I find it increasingly difficult to tell friends what they should do. It’s becoming really problematic.”
Reuters contributed reporting
George is Digismak’s reported cum editor with 13 years of experience in Journalism