COVID-19 boosters get FDA vaccine panel debate today: What happens now

The US Food and Drug Administration will begin deliberations today on whether to approve COVID-19 booster shots, following the Biden Administration's commitment to add an extra injection to those wanting to fully immunized against coronavirus. The FDA's Vaccines and Related Biological Products Advisory Committee will see representatives from Pfizer, among others, pitch the value of a third vaccine shot amid fast-spreading variants like Delta.

So far, according to the CDC's COVID-19 data tracker, 54.2-percent of the total US population are considered "fully vaccinated" while 63.5-percent have received at least one dose. For the population above 12 years of age – currently the youngest age that can receive the coronavirus vaccine – the fully vaccinated count rises to 63.5-percent.

In addition to coaxing vaccine hold-outs into getting their injection, however, attention has turned to how the current level of immunization from vaccines like those of Pfizer-BioNTech, Moderna, and J&J can handle some of the more recently-observed COVID-19 variants. Those, like Delta, have typically been more virulent, and quickly overtaken the earlier strains. While research is still ongoing, early indications suggest that the current immunization schedule may be less effective against the latter variants.

In mid-August, the CDC and FDA recommended that those in certain at-risk groups should get a vaccine booster, if they'd been initially given the Moderna or Pfizer-BioNTech vaccines. Focused on immunocompromised individuals – such as those who have received organ or stem cell transplants, who have advanced or untreated HIV infection, who are actively undertaking treatment for cancer, who are on medications which cause weakening of the immune system, or similar groups – the advice highlighted that those people had been particularly at risk of developing so-called breakthrough cases of COVID-19.

Only days later, the Biden Administration announced plans to roll out boosters to all Americans. From September, the White House explained, a third injection would be available. However, that would depend first on the FDA and CDC agreeing that the science was in favor of such a development.

It's that process which is beginning today. "Concerns have been raised that declining neutralizing antibody titers or reduced effectiveness against symptomatic disease may herald significant declines in effectiveness against severe disease," the FDA explains.

"The recent emergence of the highly transmissible Delta variant of SARS-CoV-2 resulted in a new wave of COVID-19 cases in many parts of the world and has led to considerations for administration of booster doses to individuals who received primary series of vaccines in an effort to enhance immunity, and thus sustain protection from COVID-19," the agency continues. Still, the FDA insists that the current in-use vaccines in the US deliver strong protection against serious cases of COVID-19, such as those which can lead to hospitalization or death.

Currently, only Pfizer's vaccine – which has been branded Comirnaty – has been fully approved by the FDA. Moderna and J&J's vaccines are still being used under their original emergency use authorization (EUA) during the pandemic.

Pfizer representatives will speak at today's hearing, setting out their case for why a third shot is advised. Other speakers will include head of the FDA vaccine division, the Center for Biologics Evaluation and Research, Dr Peter Marks, along with a colleague, Marion Gruber. Members of the US Centers for Disease Control and Prevention (CDC) will discuss infection rates, the variants, and cases of breakthrough infection.

The day's hearing will end with a vote, the results of which will be passed to the FDA. The decision of the panel – made up of independent public health and scientific experts – is not binding to the agency; indeed, the FDA could decide to rule differently, depending on the final outcome of today's session.

After that, the CDC will need to give its green-light to booster shots. The Biden Administration has previously said that it could begin booster distribution as soon as September 20, though the third dose should be administered no sooner than eight weeks after the second dose was injected.