Results for “first doses first”
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The problem with fitting third doses into a regulatory structure

That is a key theme of my latest Bloomberg column, here is one excerpt:

In the U.S., President Joe Biden’s administration is now pushing third booster shots for people who already have been vaccinated. That might be a good idea, but it too creates additional uncertainty for travel and migration — and for social interaction more broadly. If three doses are so important, should people be allowed to travel (or for that matter interact indoors) with only two doses? The bar is raised yet again.

Of course the issues do not end with the third dose. If the efficacy of the second dose declines significantly in less than a year, might the same happen with the third dose? How long before four doses are necessary, or maybe five? Or what if yet another significant Covid variant comes along, and only some people have a booster dose against that strain? What then counts as being “sufficiently vaccinated”?

Many Americans seem to be keen to get their third dose, but by the nature of counting that number is fewer than the number willing to get two doses. Furthermore, many people might just tire of the stress of dealing with an ongoing stream of obligatory booster shots and stop at one or two.

The sad reality is that the “two-dose standard” may not last very long, whether abroad or domestically (the same is true of the even weaker one-dose standard with Johnson & Johnson and AstraZeneca). Vaccine mandates will become harder to define and enforce, will be less transparent, and will probably be less popular.

If you tell people that three doses are needed for safety, but two doses are enough to get you into a concert or government building, how are they supposed to sort out the mixed messages? It is not obvious that enough people will get the third dose in a timely manner to make that a workable standard for vaccine passports.

Add to that the problems with the Johnson & Johnson vaccine, which originally the government urged people to get. Now those people are not being given comparable chances to obtain boosters — in fact, they are not yet being given specific guidance at all. Are they orphaned out of any new vaccine passport system, or will (supposedly dangerous?) exceptions be made for them? Or do they just have to start all over?

The big international winner from all this is likely to be Mexico, which has remained an open country and is not relying on vaccine passports. In general I do not admire Mexico’s lackadaisical Covid response, but the country may end up in a relatively favorable position, most of all when it comes to tourism and international business meetings.

As for the U.S. and Europe, the temptation to escalate required safety measures is understandable. But the previous vaccine standards were largely workable ones. If they are made tougher, they might break down altogether.

Recommended.

Second Doses Are Better at 8 Weeks or Longer

In Britain people are now being warned *not* to get their second dose at 3 or 4 weeks because this offers less protection than waiting 8 weeks or longer.

Warnings over the lack of long-term protection offered by jab intervals shorter than eight weeks come as scores of under 40s continue to receive second doses early at walk-in clinics, contrary to Government guidance.

…“There is very good immunological and vaccine effectiveness evidence that the longer you leave that second dose the better for Pfizer and eight weeks seems to be a reasonable compromise.”

Professor Harnden emphasised that “you’re definitely less protected against asymptomatic disease if you have a shorter dose interval”.

I’m so old I can remember when first doses first wasn’t “following the science.”

A Majority of Doses are Now Second Doses

As of Feb. 18 (last day of full data) we gave out 817,708 second doses and just 702,426 first doses. In other words, a majority of doses are now second doses. As Daniel Bier writes this means that we are boosting some people from ~85% to ~95% protected when we could be vaccinating more first timers and getting them from 0% protected to ~85% protected.

If we followed the British rule and delayed the booster to 12 weeks, we could immediately more than *double* the number of people going from 0% protected to to ~85% protected. More first-doses would be great for the newly protected and more people at ~85% protection would also reduce transmission so there would be fewer new infections and less threat to the non-vaccinated.

The opportunity cost of not delaying the booster is measured in lives lost.

The First Dose is Good

WSJ: The Covid-19 vaccine developed by Pfizer Inc. and BioNTech SE generates robust immunity after one dose and can be stored in ordinary freezers instead of at ultracold temperatures, according to new research and data released by the companies.

The findings provide strong arguments in favor of delaying the second dose of the two-shot vaccine, as the U.K. has done . They could also have substantial implications on vaccine policy and distribution around the world, simplifying the logistics of distributing the vaccine.

A single shot of the vaccine is 85% effective in preventing symptomatic disease 15 to 28 days after being administered, according to a peer-reviewed study conducted by the Israeli government-owned Sheba Medical Center and published in the Lancet medical journal. Pfizer and BioNTech recommend that a second dose is administered 21 days after the first.

The finding is a vindication of the approach taken by the U.K. government to delay a second dose by up to 12 weeks so it could use limited supplies to deliver a single dose to more people, and could encourage others to follow suit. Almost one-third of the U.K.’s adult population has now received at least one vaccine shot. Other authorities in parts of Canada and Europe have prioritized an initial shot, hoping they will have enough doses for a booster when needed.

Preliminary data also suggest that the other widely used vaccine in the U.K. developed by AstraZeneca PLC and the University of Oxford could have a substantial effect after a first dose .

The Israeli findings came from the first real-world data about the effect of the vaccine gathered outside of clinical trials in one of the leading nations in immunization against the coronavirus. Israel has given the first shot to 4.2 million people—more than two-thirds of eligible citizens over 16 years old—and a second shot to 2.8 million, according to its health ministry. The country has around 9.3 million citizens.

…”This groundbreaking research supports the British government’s decision to begin inoculating its citizens with a single dose of the vaccine,” said Arnon Afek, Sheba’s deputy director general.

The Israeli study is here. Data from Quebec also show that a single dose is highly effective, 80% or higher (Figure 3) in real world settings.

It’s becoming clearer that delaying the second dose is the right strategy but it was the right strategy back in December when I first started advocating for First Doses First. Waiting for more data isn’t “science,” it’s sometimes an excuse for an unscientific status-quo bias.

Approximately 16 million second doses have been administered in the US. If those doses had been first doses an additional 16 million people would have been protected from dying. Corey White estimates that every 4000 flu vaccinations saves a life which implies 4000 lives would have been saved by going to FDF. COVID, of course, is much deadlier than the flu–ten times as deadly or more going by national death figures (so including transmission and case fatality rate)– so 40,000 deaths is back of the envelope. Let’s do some more back-of-the-envelope calculations. Since Dec. 14, there have been approximately 10 million confirmed cases in the United States and 200,000 deaths. There are 200 million adults in the US so 1/1000 adults has died from COVID, just since Dec. 14. If we use 1/1000 as the risks of a random adult dying from COVID, then an additional 16 million vaccinations would have saved 16,000 lives. But that too is likely to be an underestimate since the people being vaccinated are not a random sample of adults but rather adults with a much higher risk of dying from COVID. Two to four times that number would not be unreasonable so an additional 16 million vaccinations might have avoided 32,000-64,000 deaths. Moreover, an additional 16 million first doses would have reduced transmission. None of these calculations is very good but they give a ballpark.

It is excellent news that the vaccine is stable for some time using ordinary refrigeration. Scott Duke Kominers and I argue that there is lot of unused vaccination capacity at the pharmacies and reducing the cold storage requirement will help to bring that unused capacity online. The announcement is also important for a less well understood reason. If Pfizer is only now learning that ultra-cold storage isn’t necessary then we should be looking much more closely at fractional dosing.

When I said that we should delay the second dose, people would respond with “but the companies say 21 days and 28 days! Listen to the science!”. That’s not scientific thinking but magical thinking. Listening to the science was understanding that the clinical trial regimen was designed at speed with the sole purpose of getting the vaccines approved. The clinical trial was not designed to discover the optimal regimen for public health. Don’t get me wrong. Pfizer and Moderna did the right thing! But it was wrong to think that the public health authorities could simply rely on “the science” as if it were written on stone. Even cold-storage wasn’t written on stone!  Now that the public health authorities know that the clinical trial regimen isn’t written in stone they should be more willing to consider policies such as delaying the second dose and fractional dosing.

We are nearing the end in the US but delaying the second dose and other dose-stretching policies are going to be important in other countries.

Half Doses of Moderna Produce Neutralizing Antibodies

A new phase II study from Moderna shows that half-doses (50 μg) appear to be as good as full doses (100 ug) at generating correlates of protection such as neutralizing antibodies.

In this randomized, controlled phase 2 trial, the SARS-CoV-2 vaccine candidate mRNA-1273, administered as a two-dose vaccination regimen at 50 and 100 μg, exhibited robust immune responses and an acceptable safety profile in healthy adults aged 18 years and older. Local and systemic adverse reactions were mostly mild-to-moderate in severity, were ≤4 days of median duration and were less commonly reported in older compared with younger adults. Anti-SARS-CoV-2 spike binding and neutralizing antibodies were induced by both doses of mRNA-1273 within 28 days after the first vaccination, and rose substantially to peak titers by 14 days after the second vaccination, exceeding levels of convalescent sera from COVID-19 patients. The antibodies remained elevated through the last time point assessed at 57 days. Neutralizing responses met criteria for seroconversion within 28 days after the first vaccination in the majority of participants, with rates of 100% observed at 14 and 28 days after the second vaccination. While no formal statistical testing was done, binding and neutralizing antibody responses were generally comparable in participants who received the 100 μg mRNA-1273 and the 50 μg dose at all time points and across both age groups. Overall, the results of this randomized, placebo-controlled trial extend previous immunogenicity and safety results for mRNA-1273 in the phase 1 study in an expanded cohort including participants older than 55 years of age [16, 19].

[These data] confirm that a robust immune response is generated at both 50 and 100 ug dose levels.

As I wrote earlier, halving the dose is equivalent to instantly doubling the output of every Moderna factory.

See my piece in the Washington Post on getting to V-day sooner for an overview of dose stretching strategies.

Addendum: France says one dose is sufficient for previously COVID infected.

“Second Doses” post-mortem

The most striking thing about the Biden administration shift to a version of “First Doses First” is how little protest there has been.  Given how many public health experts were upset about the idea only a few days ago, you might expect them to organize a Wall Street Journal petition from hundreds of their colleagues: “Biden administration proposal endangers the lives of millions of Americans.”

But of course they won’t do that.  Some of that is pro-Democrat partisanship, but that is not even the main factor.  One reason is that public health experts, with their medical and quasi-medical backgrounds, typically have very little sense of how to respond in the public arena if challenged.  For instance, not a single one stepped forward with a calculation to defend “Second Doses.”  They are not especially good at “the internet rules of the game,” which of course are now supreme (not always for the best, to be clear).

The second and probably most important reason is that, as I had explained, sins of omission are treated as far less significant than sins of commission.  Now that a version of “First Doses First” is on the verge of becoming policy, to do nothing about that is only a sin of omission, and thus not so bad.  Remarkable!  Status quo bias really matters here.

I haven’t seen a single peep on Twitter opposing the new policy.

Just keep all this in mind the next time you see a debate over public health policy.  There is often less behind the curtain than you might think.

Half-Doses as Good as Full?

NYTimes: A top official of Operation Warp Speed floated a new idea on Sunday for stretching the limited number of Covid-19 vaccine doses in the United States: Halving the dose of each shot of Moderna’s vaccine to potentially double the number of people who could receive it.

Data from Moderna’s clinical trials demonstrated that people between the ages of 18 and 55 who received two 50-microgram doses showed an “identical immune response” to the standard of two 100-microgram doses, said the official, Dr. Moncef Slaoui.

Dr. Slaoui said that Operation Warp Speed was in discussions with the Food and Drug Administration and the pharmaceutical company Moderna over implementing the half-dose regimen. Moderna did not respond immediately to a request for comment.

Each vaccine would still be delivered in two, on-schedule doses four weeks apart, Dr. Slaoui said in an interview with “CBS’s Face the Nation.” He said it would be up to the F.D.A. to decide whether to move forward with the plan.

Half dosing would double Moderna doses permanently rather than temporarily (as with First Doses First). Thus, I would be very happy to see half-dosing and it would obviate the need for FDF.

I and a handful of others started to discuss and advocate First Doses First on Dec. 8 and many times since then. The advocacy was then joined by Tony Blair and by many epidemiologists, immunologists, vaccine researchers, physicians and public health experts as well, of course, by the British experts on the Joint Committee on Vaccination and Immunisation. It’s clear that the FDA and Operation Warp Speed are now feeling the pressure to take some serious actions to increase supply. If so, my small efforts will have had a very high return.

Keep the pressure on.

Addendum: By the way, the British have yet to approve the Moderna vaccine (probably because they can’t get doses for some time anyway) and the AstraZeneca vaccine appears to work better with a longer dosing interval. So FDF makes sense for the British and we can do half-dosing on Moderna, potentially setting a new and beneficial standard for the entire world.

First Dose First

Writing on twitter Keith Klugman, world expert on infectious diseases and director of the Gates Foundation Pneumonia program, supports a policy I have argued for–First Doses First.

First doses of Pfizer/Moderna vaccines are 90%+ effective after 14 days. Most high risk lives will be saved by giving all these limited early supplies of vaccine as first doses – second doses can be given later if first dose effectiveness wanes or when supply improves

Here’s a way of thinking about this policy. Suppose you are scheduled for your second dose of the Pfizer or Moderna vaccine but you have the option of giving your second dose to your spouse as their first dose. Would you?

If the answer is yes then can you ethically deny this to someone else’s spouse?

Keep in mind that we have at least three more vaccines that could be available in as little as 12 weeks, Astra-Zeneca, Johnson & Jonson and Novavax. We are also pushing for more doses from Pfizer and we should be willing to pay top-dollar for those doses. As those vaccines come online we can deliver second doses.

Addendum: If you are 75 and your spouse is 25 then maybe you wouldn’t give your second dose to your spouse and that too ought to help us think about the larger questions of allocation.

The case for geographically concentrated vaccine doses

Here goes:

A central yet neglected point is that vaccines should not be sent to each and every part of the U.S. Instead, it would be better to concentrate distribution in a small number of places where the vaccines can have a greater impact.

Say, for the purposes of argument, that you had 20,000 vaccine doses to distribute. There are about 20,000 cities and towns in America. Would you send one dose to each location? That might sound fair, but such a distribution would limit the overall effect. Many of those 20,000 recipients would be safer, but your plan would not meaningfully reduce community transmission in any of those places, nor would it allow any public events to restart or schools to reopen.

Alternatively, say you chose one town or well-defined area and distributed all 20,000 doses there. Not only would you protect 20,000 people with the vaccine, but the surrounding area would be much safer, too. Children could go to school, for instance, knowing that most of the other people in the building had been vaccinated. Shopping and dining would boom as well.

Here is one qualifier, but in fact it pushes one further along the road to geographic concentration:

Over time, mobility, migration and mixing would undo some of the initial benefits of the geographically concentrated dose of vaccines. That’s why the second round of vaccine distribution should go exactly to those people who are most likely to mix with the first targeted area. This plan reaps two benefits: protecting the people in the newly chosen second area, and limiting the ability of those people to disrupt the benefits already gained in the first area.

In other words, if the first doses went (to choose a random example) to Wilmington, Delaware, the next batch of doses should go to the suburbs of Wilmington. In economics language [behind this link is a highly useful Michael Kremer paper], one can say that Covid-19 infections (and protections) have externalities, and there are increasing returns to those externalities. That implies a geographically concentrated approach to vaccine distribution, whether at the federal or state level.

Here is another qualifier:

…there will be practical limits on a fully concentrated geographic distribution of vaccines. Too many vaccines sent to too few places will result in long waits and trouble with storage. Nonetheless, at the margin the U.S. should still consider a more geographically concentrated distribution than what it is likely to do.

Do you think that travel restrictions have stopped the spread of the coronavirus? (Doesn’t mean you have to favor them, all things considered.)  Probably yes.  If so, you probably ought to favor a geographically concentrated initial distribution of the vaccine as well — can you see why it is the same logic?  Just imagine it spreading out like stones on a Go board.

Of course we are not likely to do any of this.  Here is my full Bloomberg column.

Extreme carcinogenic doses for rats

Here is a defense of using those rat tests to judge what will cause cancer in humans:

The "junk science" they are referring to is the long-standing and
well-confirmed practice of identifying chemicals likely to cause cancer
in humans by testing them in animals. The animals (rodents) are a
standard model for biological processes of relevance to humans (which
is why drug companies and medical researchers have been using them for
a century). They are well understood and are the only sentinels for
detecting carcinogenicity of any use to public health. Since chemically
induced cancer has a latency period of decades (typically 20 years or
more), waiting for it to appear in human populations would meant that
once detected, even if exposure would cease instantly (which can never
happen), it would take another 20 or more years to eliminate the
cancers from exposure (all the cancers induced in the 20 years exposure
prior to detection). But even then, the chances of detecting any but
the most powerful carcinogens in human populations (via epidemiology)
is small. Epidemiology is a very insensitive tool. I say this with some
authority, as I am a cancer epidemiologist specializing in chemical
exposures and have authored numerous peer reviewed studies in that area
over many years.

The main rhetorical lever ACSH employs is the
use of high doses in the animal studies, doses that are much higher
than usually faced by humans. But as ACSH knows well (but didn’t
divulge) there is a technical requirement for using these doses. If one
were to use doses in animals predicted to cause cancer at a rate we
would consider a public health hazard, we would need tens of thousands
of animals to test a single dose, mode of exposure and rodent species
or strain. This makes using those doses infeasible. Thus a Maximum
Tolerated Dose is used, one that causes no other pathology except
possibly cancer and doesn’t result in more than a 10% weight loss. The
assumption here is that something that causes cancer at high doses in
these animals will also do so at low doses. This is biologically
reasonable. It is a (surprising) fact, that most chemicals, given in no
matter how high a dose, won’t cause the very unusual and specific
biological effect of turning an animal cell cancerous. Cancer cells are
not "damaged" cells in the individual sense but "super cells," capable
of out competing normal cells. It is only in the context of the whole
organism that there is a problem. It is not surprising, then, that very
few chemicals would have be ability to turn a normal cell into a
biological super cell of this type. Estimates are that is far less than
10%, perhaps only 1% of all chemicals that have this ability. Thus
western industrial civilization doesn’t have to come to a screeching
halt if we eliminate industrial chemical carcinogens from our
environment.

We know of no false negatives with this process.
Every chemical we know that causes cancer in humans also does so in
rodents (with the possible exception of inorganic trivalent arsenic,
which is equivocal).

Here is the full post.  I’m not close to having the expertise to evaluate these claims, but two points.  First, the author is highly qualified; as a blogger he is anonymous but I can vouch for his credentials.  Second, it should be the self-appointed task of bloggers to pass along arguments which either struck them or which might shake up their readers.

Status Quo Bias

Here is the lead sentence from a CNN piece on vaccine boosters:

Even though the biopharmaceutical company Pfizer has announced that it might be time to consider giving a third dose of its coronavirus vaccine to people, many doctors and public health officials argue that it’s more beneficial to get shots into the arms of the unvaccinated right now than to boost those who are already fully vaccinated.

Delaying the 3rd dose to get out more 2nd doses is a perfectly reasonable position. What’s interesting is that today delaying the 3rd dose is conventional wisdom and yet this is exactly the same argument that I made for delaying the 2nd dose, i.e. first doses first (FDF), back in December of 2020. At that time, however, the argument was controversial. My point, isn’t that FDF has won the argument. My point is that what we are seeing, then and now, is status quo bias.

In December, status quo bias meant that people wanted to find a reason to stick with the status quo, i.e. 2 doses, and so they argued that delaying the second dose was “risky.” Today, people still want to stick with the status quo and so they argue that third doses are “risky”, i.e. delaying the third dose is now the less risky idea. The argument–it’s smart to protect more people with fewer doses–hasn’t changed but, without even realizing it, people are now making the argument that they once denied.

The logic hasn’t convinced people but previously the logic opposed the status quo and now it supports the status quo so what was once denied is now accepted. What was in December the riskier choice now becomes the safer choice. With motivated reasoning, when the motivation changes so does the reasoning.

Hat tip: Iamamish

Addendum: People will respond in the comments, but actually the situations are different. Indeed, things are different and the situation has changed. But that’s not the only or even the primary driver. If we had started with a 3-dose regimen, delaying the third dose would have seemed just as “risky” as delaying the second dose in a 2-dose regimen.

Addendum 2: The WHO today called for a moratorium on boosters until more countries are vaccinated.

Book Review: Andy Slavitt’s Preventable

Like Michael Lewis’s The Premonition which I reviewed earlier, Andy Slavitt’s Preventable is a story of heroes, only all the heroes are named Andy Slavitt. It begins, as all such stories do, with an urgent call from the White House…the President needs you now! When not reminding us (e.g. xv, 14, 105, 112, 133, 242, 249) of how he did “nearly the impossible” and saved Obamacare he tells us how grateful other people were for his wise counsel, e.g. “Jared Kushner’s name again flashed on my phone. I picked up, and he was polite and appreciative of my past help.” (p.113), “John Doer was right to challenge me to make my concerns known publicly. Hundreds of thousands of people were following my tweets…” (p. 55)

Slavitt deserves praise for his work during the pandemic so I shouldn’t be so churlish but Preventable is shallow and politicized and it rubbed me the wrong way. Instead of an “inside account” we get little more than a day-by-day account familiar to anyone who lived through the last year and half. Slavitt rarely departs from the standard narrative.

Trump, of course, comes in for plenty of criticism for his mishandling of the crisis. Perhaps the most telling episode was when an infected Trump demanded a publicity jaunt in a hermetically sealed car with Secret Service personnel. Trump didn’t care enough to protect those who protected him. No surprise he didn’t protect us.

The standard narrative, however, leads Slavitt to make blanket assertions—the kind that everyone of a certain type knows to be true–but in fact are false. He writes, for example:

In comparison to most of these other countries, the American public was impatient, untrusting, and unaccustomed to sacrificing individual rights for the public good. (p. 65)

Data from the Oxford Coronavirus Government Response Tracker (OxCGRT) show that the US “sacrifice” as measured by the stringency of the COVID policy response–school closures; workplace closures; restrictions on public gatherings; restrictions on internal movements; mask requirements; testing requirements and so forth–was well within the European and Canadian average.

The pandemic and the lockdowns split Americans from their friends and families. Birthdays, anniversaries, even funerals were relegated to Zoom. Jobs and businesses were lost in the millions. Children couldn’t see their friends or even play in the park. Churches and bars were shuttered. Music was silenced. Americans sacrificed plenty.

Some of Slavitt’s assertions are absurd.

The U.S. response to the pandemic differed from the response in other parts of the world largely in the degree to which the government was reluctant to interfere with our system of laissez-faire capitalism…

Laissez-faire capitalism??! Political hyperbole paired with lazy writing. It would be laughable except for the fact that such hyperbole biases our thinking. If you read Slavitt uncritically you’d assume–as Slavitt does–that when the pandemic hit, US workers were cast aside to fend for themselves. In fact, the US fiscal response to the pandemic was among the largest and most generous in the world. An unemployed minimum wage worker in the United States, for example, was paid a much larger share of their income during the pandemic than a similar worker in Canada, France, or Germany (and no, that wasn’t because the US replacement rate was low to begin with.)

This is not to deny that low-wage workers bore a larger brunt of the pandemic than high-wage workers, many of whom could work from home. Slavitt implies, however, that this was a “room-service pandemic” in which the high-wage workers demanded a reopening of the economy at the expense of low-wage workers. As far as the data indicate, however, the big divisions of opinion were political and tribal not by income per se. The Washington Post, for example, concluded:

There was no significant difference in the percentage of people who said social distancing measures were worth the cost between those who’d seen no economic impact and those who said the impacts were a major problem for their households. Both groups broadly support the measures.

Perhaps because Slavitt believes his own hyperbole about a laissez-faire economy he can’t quite bring himself to say that Operation Warp Speed, a big government program of early investment to accelerate vaccines, was a tremendous success. Instead he winds up complaining that “even with $1 billion worth of funding for research and development, Moderna ended up selling its vaccine at about twice the cost of an influenza vaccine.” (p. 190). Can you believe it? A life-saving, economy-boosting, pandemic ending, incredibly-cheap vaccine, cost twice as much as the flu vaccine! The horror.

Slavitt’s narrative lines up “scientific experts” against “deniers, fauxers, and herders” with the scientific experts united on the pro-lockdown side. Let’s consider. In Europe one country above all others followed the Slavitt ideal of an expert-led pandemic response. A country where the public health authority was free from interference from politicians. A country where the public had tremendous trust in the state. A country where the public were committed to collective solidarity and the public welfare. That country, of course, was Sweden. Yet in Sweden the highly regarded Public Health Agency, led by state epidemiologist Anders Tegnell, an expert in infectious diseases who had directed Sweden’s response to the swine flu epidemic, opposed lockdowns, travel restrictions, and the general use of masks.

Moreover, the Public Health Agency of Sweden and Tegnell weren’t a bizarre anomaly, anti-lockdown was probably the dominant expert position prior to COVID. In a 2006 review of pandemic policy, for example, four highly-regarded experts argued:

It is difficult to identify circumstances in the past half-century when large-scale quarantine has been effectively used in the control of any disease. The negative consequences of large-scale quarantine are so extreme (forced confinement of sick people with the well; complete restriction of movement of large populations; difficulty in getting critical supplies, medicines, and food to people inside the quarantine zone) that this mitigation measure should be eliminated from serious consideration.

Travel restrictions, such as closing airports and screening travelers at borders, have historically been ineffective.

….a policy calling for communitywide cancellation of public events seems inadvisable.

The authors included Thomas V. Inglesby, the Director of the Johns Hopkins Center for Health Security, one of the most highly respected centers for infectious diseases in the world, and D.A. Henderson, the legendary epidemiologist widely credited with eliminating smallpox from the planet.

Tegnell argued that “if other countries were led by experts rather than politicians, more nations would have policies like Sweden’s” and he may have been right. In the United States, for example, the Great Barrington declaration, which argued for a Swedish style approach and which Slavitt denounces in lurid and slanderous terms, was written by three highly-qualified, expert epidemiologists; Martin Kulldorff from Harvard, Sunetra Gupta from Oxford and Jay Bhattacharya from Stanford. One would be hard-pressed to find a more expert group.

The point is not that we should have followed the Great Barrington experts (for what it is worth, I opposed the Great Barrington declaration). Ecclesiastes tells us:

… that the race is not to the swift, nor the battle to the strong, neither yet bread to the wise, nor yet riches to men of understanding, nor yet favor to men of skill; but time and chance happeneth to them all.

In other words, the experts can be wrong. Indeed, the experts are often divided, so many of them must be wrong. The experts also often base their policy recommendations on factors beyond their expertise, including educational, class, and ideological biases, so the experts are to be trusted more on factual questions than on ethical answers. Nevertheless, the experts are more likely to be right than the non-experts. So how should one navigate these nuances in a democratic society? Slavitt doesn’t say.

Slavitt’s simple narrative–Trump bad, Biden good, Follow the Science, Be Kind–can’t help us as we try to improve future policy. Slavitt ignores most of the big questions. Why did the CDC fail in its primary mission? Indeed, why did the CDC often slow our response? Why did the NIH not quickly fund COVID research giving us better insight on the virus and its spread? Why were the states so moribund and listless? Why did the United States fail to adopt first doses first, even though that policy successfully saved lives by speeding up vaccinations in Great Britain and Canada?

To the extent that Slavitt does offer policy recommendations they aren’t about reforming the CDC, FDA or NIH. Instead he offers us a tired laundry list; a living wage, affordable housing, voting reform, lobbying reform, national broadband, and reduction of income inequality. Surprise! The pandemic justified everything you believed all along! But many countries with these reforms performed poorly during the pandemic and many without, such as authoritarian China, performed relatively well. All good things do not correlate.

Trump’s mishandling of the pandemic make it easy to blame him and call it a day. But the rot is deep. If we do not get to the core of our problems we will not be ready for the next emergency. If we are lucky, we might face the next emergency with better leadership but a great country does not rely on luck.

A Half Dose of Moderna is More Effective Than a Full Dose of AstraZeneca

Today we are releasing a new paper on dose-stretching, co-authored by Witold Wiecek, Amrita Ahuja, Michael Kremer, Alexandre Simoes Gomes, Christopher M. Snyder, Brandon Joel Tan and myself.

The paper makes three big points. First, Khoury et al (2021) just published a paper in Nature which shows that “Neutralizing antibody levels are highly predictive of immune protection from symptomatic SARS-CoV-2 infection.” What that means is that there is a strong relationship between immunogenicity data that we can easily measure with a blood test and the efficacy rate that it takes hundreds of millions of dollars and many months of time to measure in a clinical trial. Thus, future vaccines may not have to go through lengthy clinical trials (which may even be made impossible as infections rates decline) but can instead rely on these correlates of immunity.

Here is where fractional dosing comes in. We supplement the key figure from Khoury et al.’s paper to show that fractional doses of the Moderna and Pfizer vaccines have neutralizing antibody levels (as measured in the early phase I and phase II trials) that look to be on par with those of many approved vaccines. Indeed, a one-half or one-quarter dose of the Moderna or Pfizer vaccine is predicted to be more effective than the standard dose of some of the other vaccines like the AstraZeneca, J&J or Sinopharm vaccines, assuming the same relationship as in Khoury et al. holds. The point is not that these other vaccines aren’t good–they are great! The point is that by using fractional dosing we could rapidly and safely expand the number of effective doses of the Moderna and Pfizer vaccines.

Second, we embed fractional doses and other policies such as first doses first in a SIER model and we show that even if efficacy rates for fractional doses are considerably lower, dose-stretching policies are still likely to reduce infections and deaths (assuming we can expand vaccinations fast enough to take advantage of the greater supply, which is well within the vaccination frontier). For example, a half-dose strategy reduces infections and deaths under a variety of different epidemic scenarios as long as the efficacy rate is 70% or greater.

Third, we show that under plausible scenarios it is better to start vaccination with a less efficacious vaccine than to wait for a more efficacious vaccine. Thus, Great Britain and Canada’s policies of starting First Doses first with the AstraZeneca vaccine and then moving to second doses, perhaps with the Moderna or Pfizer vaccines is a good strategy.

It is possible that new variants will reduce the efficacy rate of all vaccines indeed that is almost inevitable but that doesn’t mean that fractional dosing isn’t optimal nor that we shouldn’t adopt these policies now. What it means is that we should be testing and then adapting our strategy in light of new events like a battlefield commander. We might, for example, use fractional dosing in the young or for the second shot and reserve full doses for the elderly.

One more point worth mentioning. Dose stretching policies everywhere are especially beneficial for less-developed countries, many of which are at the back of the vaccine queue. If dose-stretching cuts the time to be vaccinated in half, for example, then that may mean cutting the time to be vaccinated from two months to one month in a developed country but cutting it from two years to one year in a country that is currently at the back of the queue.

Read the whole thing.

The Becker-Friedman center also has a video discussion featuring my co-authors, Nobel prize winner Michael Kremer and the very excellent Witold Wiecek.

Two Vaccine Updates

First, in an article on new vaccine boosters in USA today there is this revealing statement:

Any revised Moderna vaccine would include a lower dose than the original, Moore said. The company went with a high dose in its initial vaccine to guarantee effectiveness, but she said the company is confident the dose can come down, reducing side effects without compromising protection.

Arrgh! Why wait for a new vaccine??? Fractional dosing now!

A microneedle patch for vaccines.

The same article also notes:

One of Moderna’s co-founders, MIT professor Robert Langer, is known for his research on microneedles, tiny Band-Aid-like patches that can deliver medications without the pain of a shot. Moderna has said nothing about delivery plans, but it’s conceivable the company might try to combine the two technologies to provide a booster that doesn’t require an injection.

The skin is highly immunologically active so you can give lower doses with a microneedle patch. The microneedles are sometimes made from sugar and don’t hurt. Microneedle delivery, however, can cause scars but I say apply the patch where the sun don’t shine and let’s go!

Second, Canada’s NACI has now endorsed mix and match for the AZ and Pfizer and Moderna vaccines. First Doses First has put Canada in very good shape (now ahead of the US in percent of the population with at least one dose) and this was always part of the FDF plan–delay second doses to get out more first doses and then, when supplies increase, give second doses, possibly with a better vaccine.

India Delays the 2nd Dose; Delaying 2nd Dose Improves Immune Response; Fractional Dosing

India has delayed the second dose to 12-16 weeks.

In other news, delaying the second dose of the Pfizer vaccine appears to improves the immune response (as was also found for the AstraZeneca vaccine). The latter is a news report based on a press release so some caution is warranted but frankly this was always the Bayesian bet since most vaccines have a longer time between doses as that helps the immune system. As Tyler and myself both argued, the short gap between the first and second dose was chosen to speed up the clinical trials not to maximize immunity. That was the right decision in the emergency but it was never the case that following the clinical trial regimen was “going by the science” no matter what Fauci said.

Many lives have been lost by not going to first doses first earlier, both here and in India.

Every country should move to a regimen in which the second dose comes at 12-16 weeks, even the United States, as this may improve the immune response and help other countries get a little bit ahead in their vaccine drives.

May I now also beat the drum some more on fractional dosing? Many people (not everyone) report that the second mRNA dose packs a wallop. I suspect that a half dose at 12-16 weeks would be plenty and that would free up significant capacity to vaccinate more people with first doses. We could also run some trials on half-doses for the young as a way to balance dosing and risk. Again this will matter for the rest of the world more than the United States but stretching doses in the United States will help the rest of the world and the arguments against stretching doses are now much diminished.