Debate continues over Covid booster shots
Dr.Sara Oliver, a Centers for Disease Control and Prevention official who leads the COVID-19 vaccines work group, on Monday said the “priority for booster dose policy should be the prevention of severe disease in at-risk populations,” citing nursing-home residents and frontline healthcare workers as examples.
The presentation was part of a meeting of the CDC’s Advisory Committee on Immunization Practices, or ACIP, a group of independent public health experts who make recommendations about vaccines to the CDC following authorization or approval from the Food and Drug Administration.
White House officials, including President Joe Biden, last month said that Americans who were vaccinated with the vaccines from BioNTech SE and Pfizer Inc. or Moderna Inc. can get a booster dose starting Sept. 20, as long it has been eight months since the person has been fully vaccinated, the FDA authorizes or approves the booster, and the CDC gives its blessing. They said the first boosters will likely go to groups of people who are at higher risk of severe disease. The White House also said that people who got Johnson & Johnson’s single-shot vaccine will likely need a second dose, though no further details have been shared at this time.
That said, U.S. regulators have yet to OK a booster dose for the general public, and that has become a point of contention for some public health experts.
The Biden administration’s announcement “led everyone — it led physicians, it led the public — to believe that they had access to information about these vaccines and the need for boosters that had not yet been publicly released,” Dr. Sandra Adamson Fryhofer, an adjunct associate professor of medicine at Emory University School of Medicine, said Monday. “To me, that opened the door to a lot of confusion.”
Fryhofer serves as a liaison to ACIP for the American Medical Association. Federal health officials have said they are concerned that the vaccines will soon be less effective at protecting people against severe disease, hospitalization and death, and that is their rationale for booster shots.
Asked about the ACIP’s booster discussion on Tuesday, CDC director Dr. Rochelle Walensky responded that the committee had only evaluated U.S. data so far. “It is our own data as well as international data that has led us to be concerned that the waning we’re seeing for infection will soon lead to waning that we would see for hospitalization and severe disease and death,” she said.
However, infectious-disease physicians have previously told Market Watch that clinical decisions for COVID-19 booster shots should be based on data that’s available, not what’s projected to happen.
The national discourse around boosters has intensified over the last two months, driven by public promotion from Pfizer and Moderna, the Biden administration’s sudden support, and widespread utilization of extra doses in Israel, which is being closely watched by scientists to see how virus behaves in the highly vaccinated country.
At the same time, cases have steadily increased in the U.S. since early July, as immunity has waned over time and the rapid spread of the more infectious delta variant has led to an increase in infections among the unvaccinated as well as the vaccinated.
This was reiterated by Oliver at Monday’s meeting.
“All [COVID-19] vaccines remain effective in preventing hospitalization and severe disease, but they may be less effective in preventing infection or mild illness recently,” she said. “These reasons for lower effectiveness likely include both waning over time and the delta variant.”
However, most of the soaring numbers of hospitalizations and deaths we are seeing right now are occurring in unvaccinated Americans.
“The data to date doesn’t show a remarkable reduction in the effectiveness of vaccines in terms of preventing hospitalizations and deaths,” Dr. Beth Bell, a clinical professor at the University of Washington’s School of Public Health and an ACIP member, said Monday. “The most important thing that we can do with respect to vaccines is to continue to work as hard as we possibly can to encourage more people to get the primary series.”
What exactly is a COVID-19 booster shot?
The CDC does not refer to an extra dose administered to the immuno-compromised as a booster shot. Instead, that is considered a third — or extra — dose because many of those people never mounted an immune response at all to initial vaccination, according to Oliver. (The only Americans who are currently eligible for an extra dose of the BioNTech/Pfizer vaccine — now marketed as Comirnaty — or the Moderna vaccine are some teens and adults with compromised immune systems, an authorization that was granted in August.)
The agency defines a booster dose as one that “boosts” immunity from a vaccine’s “primary series” that has waned over time.
There are also different kinds of boosters. A homologous booster uses the same vaccine, while a heterologous booster uses a different vaccine for the booster from that used in the primary series. (Market Watch)