FDA expected to authorize COVID-19 boosters for the immunocompromised

The Food and Drug Administration (FDA) is expected to authorize the administration of a third dose of some COVID-19 vaccines for immunocompromised patients.

The New York Times reports that the decision to expand the emergency use authorizations could come as soon as today as the highly contagious Delta variant continues to kick cases to record levels particularly in Florida and Texas. The expanded emergency use authorizations would allow for third doses of the Pfizer and Moderna COVID-19 vaccines.

The Biden administration is reportedly planning to release a booster shot strategy for all vaccinated Americans next month.

The authorization would enable physicians to give the additional doses to the estimated 3 percent of Americans, or about 9 million, with weakened immune systems. The vaccines are believed to be less effective in this group of people, but the initial hope was that widespread vaccinations would protect the immunocompromised population. As of Aug. 12, slightly more than half of eligible Americans, 167.1 million, have been fully vaccinated.

The Times reports that the FDA is awaiting more clinical data before making a determination on additional doses of the single-shot Johnson and Johnson vaccine.

The move to expand the authorization is an about-face for the agency, as last month FDA leaders joined with leaders of the Centers for Disease Control and Prevention (CDC) to release a statement expressing skepticism about the need for a third shot, citing the protections offered by the available two-dose regimens and urging the unvaccinated to get fully vaccinated.

The CDC has now come out in favor of COVID-19 vaccination for pregnant patients and those who live in the same household as pregnant patients citing the group’s increased risk of severe illness.

Pfizer’s push

Pfizer has been on the forefront of preparing for booster doses of their vaccine announcing that they’d seek authorization for an additional shot in July.

The company test results which indicate a third dose of the current BNT162b2 vaccine given six months after the second dose has a consistent tolerability profile and elicits high neutralization titers five or 10 times higher than the primary doses.

When it comes to the Delta variant, the two-dose regimen have strong neutralization titers, but the company believes those protections would increase with a third dose. They are conducting pre-clinical and clinical tests to prove this hypothesis.

They also released a study which has not been peer-reviewed or published in a medical journal, which found that the company’s two-dose vaccine produced a 96 percent efficacy rate against symptomatic COVID-19 two months after the second shot, but the protection fell every two months after that coming to about 83.7 percent efficacy after four to six months.