Are we really still sticking with the eight-month timetable for boosters or is this finally enough evidence to make them move it up to six?

Assuming boosters are needed at all, I mean. Some scientists still haven’t reached that conclusion, particularly for the under-65 segment of the population.

Maybe this new data is a byproduct of waning immunity, in which case a third shot would be useful. Or maybe it’s an artifact of Delta being more virulent, in which case it might not be. That’s the crux of the scientific dispute at the moment.

The CDC has previously estimated that 97% of people in the hospital being treated for COVID-19 are unvaccinated, but that data was collected before the spread of delta, a hyper-transmissible variant that many doctors have warned appears to be making people sicker…

The latest CDC analysis estimates that the ability of the COVID vaccines to keep a person out of the hospital is now between 75% to 95%.

For people older than 75 in particular, vaccine effectiveness against hospitalization experienced the steepest decline, from more than 90% to 80% between June and July.

Eighty percent effectiveness against hospitalization is still solid for an elderly cohort (among adults aged 18-49 it was 94 percent) but not as solid as it used to be, a trend that bodes ill as we approach winter. A study from the UK released last week indicates Delta is more than twice as likely to cause hospitalizations as earlier variants were, another ominous data point for seniors especially. That’s a slam-dunk case for third doses, right?

Well … read this. The data from Israel showing that immunity “waned” in senior citizens could have less to do with waning than with older, wealthier Israelis who were vaccinated early on having done more traveling this summer. Maybe they were more likely to pick up Delta while abroad and Delta was able to punch through their immunity more frequently due to their age, creating the illusion of waning immunity. Likewise, maybe we’re seeing more people in the hospital over there and over here not because immunity is waning but because vaccinated people are more willing to socialize than they were six months ago. More face-to-face contact plus a much more contagious variant equals more infections, which in turn means more hospitalizations. Immunity might not be fading so much as vaccinated people are just running headlong into a more powerful strain of COVID.

Then again, why hospitalizations might be rising isn’t the key question for booster shots, right? The question is whether a third dose will reduce your chances of contracting COVID and landing in the hospital. Doesn’t matter if it improves your odds because it restores waning immunity or because you need extra immunity to fend off Delta. It’s a simple matter of “Does the third shot work? Would we benefit from it?”

It seems clear that we would, especially older people:

Israeli data for 1 million people, age > 60, 4 million person-days with no booster vs 3.4 million person-days with booster
>10-fold reduction of severe illness
~11 fold reduction of infections
Preprint by @MiloLabWIS @IsraelMoH and colleagues just postedhttps://t.co/kSl7XcDoKz pic.twitter.com/wEpKsfZ93i

— Eric Topol (@EricTopol) August 29, 2021

Israel: For 45 days the number of severely ill hospitalized patients doubled every 10 days

Two weeks after the third dose campaign started, this exponential growth stopped

Yellow: Doubling every 10 days
Blue: Actual number of severely ill patients pic.twitter.com/si0pAz0Ovw

— Eran Segal (@segal_eran) August 31, 2021

Virologist Trevor Bedford crunched the data in this Twitter thread and came away satisfied that the vaccines remain solid against severe illness but clearly have seen some decline in effectiveness against infection in the age of Delta. That’s reason enough to justify a booster, Bedford pointed out. If the extra antibodies in boosted people can cut transmission, that’ll make for a smaller wave this winter and less strain on hospitals:

Even if protection against severe outcomes remains robust, observed waning suggests that boosters will be necessary to reduce circulation. Delta has generated a late summer wave, but steady state is likely a winter “COVID season” with vaccination recommended beforehand. 14/14

— Trevor Bedford (@trvrb) August 31, 2021

As depressing as the news has been this summer about Delta rampaging across the American south and filling up hospitals, there is one good thing that’s come out of it. Vaccine lotteries haven’t done much to encourage immunization, nor has media condemnation of the unvaccinated. But the combination of full FDA approval of the Pfizer vaccine and the rising chances of suffering in an ICU ward with advanced COVID has combined to soften up some of the opposition to getting vaccinated.

The slow and steady decline of the vaccine skepticshttps://t.co/OwJxBnD1p5 pic.twitter.com/Ksd9TbC8Ra

— Aaron Blake (@AaronBlake) August 31, 2021

The frightening surge of pediatric hospitalizations has also spooked parents into coming around on vaccinations for kids. As recently as two weeks ago, says Axios, just 56 percent of moms and dads said their children are vaccinated or are likely to be once they’re eligible. Two weeks later, with school starting and reports of classroom outbreaks circulating, that share has leaped to 68 percent. Meanwhile, nearly a third of unvaccinated adults now say they’re likely to get vaccinated thanks to the FDA officially taking Pfizer out of the “experimental” category (which was never really a thing in the first place):

29% of unvaccinated Americans say they’re likely to get inoculated in the next month given FDA’s full approval of the Pfizer shot. https://t.co/ovCIzVAH8z pic.twitter.com/MQ2sLYhywk

— Morning Consult (@MorningConsult) August 30, 2021

All of this has been happening amid chatter from the feds about boosters, undercutting the idea that talking about third doses would discourage the unvaccinated from getting their first two. If there was ever anything to that, terror over Delta seems to have overwhelmed it. In fact, average daily doses in the U.S. now stand at a shade under 900,000, the highest level since July 4. Let’s get those third doses into seniors’ arms ASAP.