FDA signals apprehension about COVID-19 vaccine booster shots

COVID-19 immunization by the National Guard

Army National Guard, Christina Alexander / Flickr cc

Tomorrow's VRBPAC (Vaccines and Related Biological Products Advisory Committee) meeting will consider Pfizer/BioNTech's application for a COVID-19 vaccine booster dose, but the Food and Drug Administration (FDA) has signaled in a new report today that booster doses, though effective, are not indicated at this time for most Americans.

The FDA said while some observational studies do show Pfizer's vaccine has waning protection against the Delta (B1617.2) variant, other studies do not.

Pfizer's mRNA-based vaccine is the only FDA-approved COVID-19 vaccine for use in the United States, and the company's application is for a third booster dose to be given 6 months after the initial two-dose series. Currently the FDA has authorized the emergency use of a third dose of Pfizer for immunocompromised Americans.

"Overall, data indicate that currently US-licensed or authorized COVID-19 vaccines still afford protection against severe COVID-19 disease and death in the United States. There are many potentially relevant studies, but FDA has not independently reviewed or verified the underlying data or their conclusions," the report reads.

The FDA said any approved booster needs to take into account how many hospitalizations and deaths the booster would offer protection against, not just data showing that boosters elicit strong immune responses in recipients.

(See related CIDRAP News story today, "Studies show good COVID booster effect, waning 2nd-dose protection.)

Pfizer: Boosters needed

Pfizer also produced a report for VRBPAC and said boosters were needed as their vaccines show 6% waning protection every 2 months. By 6 to 8 months, the vaccine offers vary limited protection, Pfizer said.

The drugmaker also cited a retrospective study from Kaiser Permanente, which "suggests that the observed erosion in vaccine effectiveness is likely primarily due to waning effectiveness rather than due to Delta escaping vaccine protection, given that (i) effectiveness against Delta infections was >90% early on; (ii) vaccine effectiveness decreases with increasing time since being fully vaccinated, irrespective of variant."

Today Moderna said it has new data suggesting that a booster dose of its mRNA vaccine would be beneficial, according to CNBC. The phase 3 data is not peer-reviewed yet, but it shows more breakthrough COVID-19 cases among recipients who were vaccinated 1 year ago versus those vaccinated 6 months ago.

Last month, the Biden administration said Americans would be getting booster doses of vaccine by Sep 20, pending approval from regulatory agencies.

Vaccination rates dropping again

The number of Americans getting a first dose of COVID-19 vaccine is declining again after a brief uptick in August, Bloomberg reports. The drop is being led by the South and Central regions of the United States, including Texas, Louisiana, Arkansas and Florida.

The Centers for Disease Control and Prevention (CDC) COVID Data Tracker shows 54.1% of Americans are fully vaccinated, and 63.4% have received at least one dose of COVID-19 vaccine. Overall, 1.92 million Americans have received their first dose since Aug 13.

President Biden last week encouraged entertainment venues to require vaccinations among customers, and today the New York Times reports that Los Angeles County will begin requiring proof of COVID-19 vaccination to enter bars, nightclubs, and other drinking establishments starting next month. Patrons and employees must show a first dose on or by Oct 7, and both doses by Nov 4.

And people applying to immigrate to the United States will be required to be vaccinated, beginning Oct 1, as part of a required medical exam, NPR reports.

Yesterday the country tracked 152,605 COVID-19 cases, including 1,943 deaths, according to the New York Times. The 7-day average of new daily COVID-19 cases is 152,741, according to the Washington Post tracker.

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