The recommendation, which is not binding for the FDA, did nothing to focus, let alone end the acrimonious US discussion over whether boosters are necessary and for whom.  Scientists and the public in general both hope that the decisions to be made by the FDA and the Centers for Disease Control (CDC) over the coming week will be the accepted by all.

Out of concern over rapidly rising Covid infection numbers, the Biden administration in mid-August announced that its booster campaign would start on Sept. 20,  subject to FDA approval, thereby upsetting the science world’s apple cart. Critics said it should have considered that many studies cited as showing the need for a third dose had not yet been peer reviewed, and for this reason the FDA might need more time to make a decision.

In its Friday vote, the advisory panel first made its decision against universal boosters and then sought to define who might benefit from them. On the second point, the panelists unanimously supported shots for the selected groups. In a subsequent informal survey by the FDA, most also supported a third Pfizer/BioNTech booster dose for healthcare workers and others at high risk of occupational coronavirus exposure.

Differences of opinion within the FDA

Though the FDA usually accepts the panel’s advice without much ado, this time the agency is split into different major camps. Two weeks ago, its top vaccine experts, Marion Gruber, director of the Office of Vaccines Research and Review (OVVR), and deputy director Phillip Krause both resigned in protest of what they said was the likelihood that the health agency’s leadership would simply nod off on the White House’s rollout plan. 

Gruber and Krause also were among 18 FDA career scientists who published an article in medical journal The Lancet questioning the administration’s judgment. The authors said they opposed boosters for everyone as the two-dose vaccines in circulation were still effective against severe illness. Getting a third shot that is not needed could cause people to suffer from dangerous side effects for no reason, they said. At the same time, the group recommended that any surplus doses be donated to less privileged countries in order to prevent more loss of life and stop more variants from forming.

Making it harder to come to a definitive decision on boosters, the FDA  is not the only US authority to have a say in the matter. Though the drugs regulator determines  the legal framework, the CDC’s advisory panel has charge of determining which populations should get the shot first and how soon after the second dose. This latter’s advisory panel is due to grapple with the question on Wednesday and Thursday and the FDA is expected to announce its decision by the end of the week.

These decisions will impact solely Pfizer/BioNtech’s Cominarty, as the American-German alliance is  the only manufacturer to have received full approval for its vaccine. Moderna is expected to ask for booster approval as soon as its shot gets full FDA clearance. The vaccine makers are now working on new formulations that could target the Delta variant, which now accounts for nearly all new Covid cases in the US, as well as special booster doses.  The first Comirnaty shots to be administered would be identical to the first two doses. 

Concern over waning vaccine efficacy

Concern over the potentially waning efficacy of all vaccines, but in particular Comirnaty, is growing in the US. Contributing to the uncertainty are diverging reports on how long protection lasts. Based on data from roughly 3,700 adults hospitalized across the US from March to August 2021, the CDC’s latest Morbidity and Mortality Weekly Report said that the protection from hospitalization afforded by the Pfizer/BioNTech shot was seen to drop from 91% during the first 120 days following  vaccination to 77% afterward.

In the same study, the Moderna vaccine, which has a comparatively higher mRNA content, showed no comparable decrease in protection over the same period, the CDC said. Not enough people had received the single-dose Johnson & Johnson vaccine to compare its performance, it added.

As Gruber and Krause noted, other studies have shown Comirnaty’s effectiveness against hospitalization remaining at around 90%, despite the spread of the Delta variant and the lengthening time since the first people received their second shots. While Pfizer, which co-sponsored one of the studies, pointed to Israeli data suggesting that protection against severe disease wanes over time, some on the FDA panel said  that the US and Israel define “severe disease” differently.

Confusion about which scientific or political opinions they should believe is leading many Americans to decide for themselves whether they should get a booster. This is facilitated by the fact that not all US vaccine centers, pharmacies or physicians ask for documentation of previous vaccinations or even proof of identity. Many fear that the lack of information about the number of shots administrated to whom and individuals’ reaction to the shot could complicate the task of monitoring.  

Author: Dede Williams, Freelance Journalist