Tomorrow, the FDA will review Pfizer's application to provide a third booster shot, and a summary of what's to be reviewed tomorrow can be found HERE at https://www.fda.gov/media/152176/download.
So there's a bit of controversy over this, and not the usual suspects - the scientific community itself appears to be split.
Now - there is no question that real-world follow-up studies have shown Pfizer and Moderna's mRNA-based vaccines have been able to provide efficacy against regular COVID, and at least some efficacy against variants including the delta variant.
The question is around the booster-shot study that Pfizer used was a small study in Israel of 312 patients, showing increased antibodies/immunity for 30 days, using the exact same formulation as was implemented previously with no additives.
Pfizer also used the same study to suggest that immunity can wane over time - but also has no definitive proof of that, as it was a small study, and parameters for durability of response were not well defined, nor had enough time passed to determine that with absolute certainty.
Historically, the FDA does not approve drugs based on small studies with a small population size and short clinical trial periods, but there are two exceptions - uncommon/rare/orphan disease or public-health emergency.
If the drug is approved for public-health emergency, then real-world studies back it up, the drug will receive full regular-use approval. (This was the case with the original vaccines, who originally used small studies to gain emergency FDA approval, and only received regular-use approval a month ago).
Thus, the scientific community is split on whether giving a third shot of the exact same formulation provides any additional benefit, especially to justify the extra expense, based on one small study, typically only considered by the FDA during public-health emergencies, and then only authorized for emergency use until there's more real-world evidence.
Now, let's go back how vaccines and their boosters vary ...
Unlike Pfizer and Moderna's vaccines, your basic yearly flu shots are NOT yet based on mRNA technology (but they're in the works).
Flu shots are currently still based on weakened strains of the actual influenza virus. Each year, any new mutation variants are added to the flu-shot formulation.
J&J and AstraZeneca's COVID vaccines are also NOT mRNA vaccines, they also use weakened "live strains."
However, Pfizer COVID-19 vaccines ARE based on mRNA, the base genetic code for coronavirus genotypes - just add specific genetic info for SARS-CoV-2.
This is the reason why the Pfizer and Moderna vaccines have offered at least some protection against variants of SARS-CoV-2, while J&J and AstraZeneca's "live strain" vaccinations have not fared as well with variants.
So now, the question the FDA is asking itself is:
"Would a third shot of the exact same formulation of the original mRNA vaccines offer additional or even incremental benefit, especially considering the study sample population size was only 312 people?
Well, of course, Pfizer's going to tell you "yes" regardless lol.
They're playing the "offers incremental benefit" card, more than the "additional benefit" card, you see, which typically only flies here in the U.S. versus Europe - or I should say at least European countries are more stringent with their definition of drugs that provide incremental or additional benefits (particularly France) ;)
Let us also not forget that recently, the FDA broke its own rules with Aduhelm (adalimumab, first drug for Alzheimer's, shown to show little if any efficacy), so who knows what will happen.
However, methinks Pfizer first needs to answer this question ...
"Do mRNA vaccines also need to be adjusted to include more specific genetic components for variants in booster shots, like live-strain vaccines - or not?"
Now THAT is truly the billion-dollar question - one that Pfizer needs to answer, if they can yet - and I'm not sure they can yet?
Having said that, if they approve the third shot, emergency status or not, if it's still free, I'll probably get it.
Because it at least it offers that 30-day immunity boost, and we suffered no ill effects (other than increased bleeding for me, one month, and exercise stamina reduction for a week or so), and we've clearly benefitted, considering Kentucky ranks right up there in cases and Trumpers lacking in common sense with viruses and we've not contracted it, plus we traveled to the same type of territory in North Carolina - twice - also wearing masks indoors, of course.
However, I'd really like to know that answer to that last question, as soon as they can, too ;)