Who was it again who nixed the idea of spacing out the first and second doses in the U.S. several months ago, back when the UK was embarking on its “first doses first” approach?

Oh right. It was that guy.

“We’re telling people [two shots] is what you should do … and then we say, ‘Oops, we changed our mind’?” [Anthony] Fauci said. “I think that would be a messaging challenge, to say the least.”…

Fauci said the science doesn’t support delaying a second dose for those vaccines, citing research that a two-shot regimen creates enough protection to help fend off variants of the coronavirus that are more transmissible, whereas a single shot could leave Americans at risk from variants such as the one first detected in South Africa. He also said there is insufficient evidence of the benefit of a single Pfizer or Moderna dose — or data showing how long the immunity conferred by one shot would last. “You don’t know how durable that protection is,” he said.

The UK went ahead with its strategy, which called for delaying the second dose of Pfizer and Moderna by three months instead of three to four weeks so that the available supply of vaccines could be dosed out to a greater number of people. Because the first dose provides strong (but maybe not very durable) protection, the idea was that the country could get closer to herd immunity sooner if a large number of people had one dose instead of a smaller number of people having two.

Two and a half months later, with the UK having recently begun to lift a national lockdown, their case curve looks like this:

Average daily deaths country-wide are down to … nine. Single digits.

But wait. Not only did the “first doses first” strategy (plus the lockdown) help Great Britain rapidly crush its curve, it might have delivered an amazing immunity bonus as well. With some vaccines, delaying the booster shot results in a higher quantity of antibodies than if the booster were given relatively soon after the first dose, as we’ve been doing in the U.S. According to a new study from the UK, the same thing is happening with the Pfizer vaccine. By pushing the second dose out to three months, the Brits may have primed their population for exceptionally strong immunity after the booster:

Most people who have both shots of the vaccine will be well protected regardless of the timing, but the stronger response from the extra delay might prolong protection because antibody levels naturally wane over time…

The scientists analysed blood samples from 175 over-80s after their first vaccine and again two to three weeks after the booster. Among the participants 99 had the second shot after three weeks, while 73 waited 12 weeks. After the second dose, all had antibodies against the virus’s spike protein, but the level was 3.5 times higher in the 12-week group.

The researchers then looked at another arm of the immune system, the T cells that destroy infected cells. They found that T cell responses were weaker when the booster was delayed, but settled down to similar levels when people were tested more than three months after the first shot.

We could have had that *plus* many more people partially vaccinated much more quickly, which might have saved many lives. Fauci blew it again.

Didn’t he?

Well, hold on.

Today, the same day that the good news about the “first doses first” approach emerged, the UK is grappling with ominous news about the B.1.617 variant, a.k.a. the “double mutant,” a.k.a. the Indian variant that may or may not have brought that country to its knees. (Scientists still aren’t sure yet to what extent B.1.617 is responsible for India’s apocalyptic outbreak.) Britain’s chief medical advisor, the UK’s answer to Fauci, warned the country this morning that if the variant is as fearsome as early data suggests, the future might be grimmer than they’ve been expecting:

“We expect over time this variant will overtake and come to dominate in the UK in the way that the Kent variant did,” he added.

The Scientific Advisory Group for emergencies has said there is a “realistic possibility” that the variant could be as much as “50% more transmissible” than the Kent strain.

Public Health England figures released on Thursday have risen from 520 cases up to 5 May to 1,313 cases.

The “Kent variant” is what you and I know as the British variant, B.1.1.7, the highly contagious strain of the virus that burned through Europe and is burning through parts of India right now. That one is known for its high transmissibility. Yet the Brits have reason to believe that the Indian variant may be even more contagious than their own homegrown variant is.

Which, if true, would help explain how India went from a relatively mild pandemic to hell on earth in the span of a month or so.

A reporter from the Independent clipped a few other key passages from today’s UK report on the variant:

And the vaccines may offer less protection from infection, meaning those vaccinated but infected may spread it to those not yet protected pic.twitter.com/Z8Itv9dJeA

— Shaun Lintern (@ShaunLintern) May 14, 2021

“A substantial resurgence of hospitalizations.” Boris Johnson told his constituents today, “I have to level with you that this new variant could pose a serious disruption to our progress and could make it more difficult to move to step four in June,” when the country was supposed to finally fully emerge from lockdown. Imagine launching a national immunization program, doing spectacularly well at it, and having a confounding strain of the virus arrive just as you’re about to receive your normalcy dividend.

But here’s the kicker:

“At this point in the vaccine roll out, there are still too few adults vaccinated to prevent a significant resurgence that ultimately could put unsustainable pressure on the NHS” #COVID19 pic.twitter.com/2mPOmUiwF3

— Shaun Lintern (@ShaunLintern) May 14, 2021

The “first doses first” strategy means that a great many Brits are still only partially protected at a moment when the Indian variant is poised to burn through the country. Early indications are that the mRNA vaccines should work against the variant, albeit possibly with less effectiveness, but it’s anyone’s guess how well they’ll work for someone who’s received only one dose. Johnson is sufficiently worried about it that he’s calling on people who’ve had their first dose to get their second within eight weeks instead of the standard 12 and he’s sending out the army to certain locations to speed up immunizations before B.1.617 starts its rampage.

So maybe Fauci was … right. If the Indian variant runs wild internationally, we might be glad that we took care to make sure Americans were fully vaccinated as quickly as possible. Stay tuned.