Results for “fractional dosing”
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Thailand and The WHO on Fractional Dosing

Thailand will study fractional dosing:

Thailand is studying the possibility of injecting coronavirus vaccines under the skin to try to stretch its limited supply, a health official said on Thursday, as the country races to inoculate the public faster amid a worsening epidemic.

“Our previous experience shows that intradermal injections uses 25% of a muscular injection, but triggers the same level of immunity,” head of the medical science department, Supakit Sirilak told reporters.

I am also pleased that the WHO’s SAGE has issued an interim statement on fractional doses:

WHO, with support of the Strategic Advisory Group of Experts (SAGE) on Immunization and its COVID-19 Vaccines Working Group, is reviewing the role of fractionating doses as a dose-sparing strategy in light of global vaccine supply constraints. SAGE is continuously reviewing the literature and has reached out to vaccine manufacturers and the research community for available information.

….While SAGE acknowledges the potential public health benefits of dose-sparing strategies to increase vaccine supply and accelerate population-level vaccination coverage, and possibly also a reduction in reactogenicity, SAGE considers there is currently insufficient evidence to recommend the use of fractional doses. Any use of a fractional dose at this point in time constitutes an off-label use of the vaccine. SAGE encourages research in the area, with a particular emphasis on research into using fractionated doses as potential boosters and fractional doses in children and adolescents.  Programmatic and operational considerations should be considered from the start.

The statement is reasonable but could have used some cost-benefit analysis. Given shortages, I’d push for a challenge trial or some field trials. I agree that if we are to have boosters and to vaccinate young children we should be looking very hard at fractional doses as they are likely to be sufficient for purpose and to preserve as much supply as possible for the rest of the world.

By the way, I think you can also see some status quo bias in the WHOs position on boosters: they are not (yet) enthusiastic about increasing supply with fractional doses but they are very negative about reducing supply with boosters. What a miracle that the status quo is just right!

In the context of ongoing global vaccine supply constraints, administration of booster doses will exacerbate inequities by driving up demand and consuming scarce supply while priority populations in some countries, or subnational settings, have not yet received a primary vaccination series.

The WHO also doesn’t note that if developed countries go for boosters then the case for fractional doses elsewhere to make use of the even more limited supply is likely even stronger.

Here’s my paper with co-authors on fractional doses.

Hat tip: Witold.

Use Fractional Dosing to Speed Vaccination and Save Lives

I’ve been shouting about fractional dosing since January, most recently with my post A Half Dose of Moderna is More Effective Than a Full Dose of AstraZeneca and the associated paper with Michael Kremer and co-authors. Yesterday we saw some big movement. Writing in Nature Medicine, WHO epidemiologists Benjamin Cowling and Wey Wen Lim and evolutionary biologist Sarah Cobey title a correspondence:

Fractionation of COVID-19 vaccine doses could extend limited supplies and reduce mortality.

Exactly so. They write:

Dose-finding studies indicate that fractional doses of mRNA vaccines could still elicit a robust immune response to COVID-192,3. In a non-randomized open-label phase 1/2 trial of the BNT162b2 vaccine, doses as low as one third (10 μg) of the full dose produced antibody and cellular immune responses comparable to those achieved with the full dose of 30 μg (ref. 4). Specifically, the geometric mean titer of neutralizing antibodies 21 days after the second vaccine dose was 166 for the group that received 10 μg, almost the same as the geometric mean titer of 161 for the group that received 30 μg, and 63 days after the second dose, these titers were 181 and 133, respectively4. For the mRNA-1273 vaccine, a dose of 25 μg conferred geometric mean PRNT80 titers (the inverse of the concentration of serum needed to reduce the number of plaques by 80% in a plaque reduction neutralization test) of 340 at 14 days after the second dose, compared with a value of 654 for the group that received the standard dose of 100 μg (ref. 5). According to the model proposed by Khoury et al.6, if vaccine efficacy at the full dose is 95%, a reduction in dose that led to as much as a halving in the post-vaccination geometric mean titer could still be in the range of 85–90%. Although other components of the immune response may also contribute to efficacy, these dose-finding data are at least indicative of the potential for further exploration of fractionation as a dose-sparing strategy. Durability of responses after fractional doses should also be explored.

…Concerns about the evolution of vaccine resistance have been posited as a potential drawback of dose-sparing strategies. However, vaccines that provide protection against clinical disease seem to also reduce transmission, which indicates that expanding partial vaccination coverage could reduce the incidence of infection. As described in a recent paper, lower prevalence should slow, not accelerate, the emergence and spread of new SARS-CoV-2 variants8.

…In conclusion, fractionated doses could provide a feasible solution that extends limited supplies of vaccines against COVID-19, which is a major challenge for low- and middle-income countries.

Also a new paper in preprint just showed that 1/4 doses of Moderna create a substantial and lasting immune response on par with that from natural infection.

Here we examined vaccine-specific CD4+ T cell, CD8+ T cell, binding antibody, and neutralizing antibody responses to the 25 ug Moderna mRNA-1273 vaccine over 7 months post-immunization, including multiple age groups, with a particular interest in assessing whether pre-existing crossreactive T cell memory impacts vaccine-generated immunity. Low dose (25 ug) mRNA-1273 elicited durable Spike binding antibodies comparable to that of convalescent COVID-19 cases. Vaccine-generated Spike memory CD4+ T cells 6 months post-boost were comparable in quantity and quality to COVID-19 cases, including the presence of TFH cells and IFNg-expressing cells.

Finally, an article in Reuters notes that Moderna are preparing to launch a 50 ug dose regimen as a booster and for children. Thus, contrary to some critics of our paper, the technology is ready.

Frankly, governments are way behind on this–they should have been pushing the vaccine manufacturers and funding trials on alternative dosing since at least January. Indeed, imagine how many lives we might have saved had we listened to Operation Warp Speed advisor Moncef Slaoui who advocated for half doses in January. On a world scale, we could have vaccinated tens even hundreds of millions more people by now had we ramped up fractional dosing.

At this point, it’s my view that there is enough knowledge to justify rolling out alternative dosing in any hot spot or in any country worried about outbreaks. Roll it out in a randomized fashion (as Kominers and I discussed in the context of the US vaccination rollout) to study it in real time but start the roll out now. Lives can be saved if we speed up vaccination, especially of the best vaccines we have, the mRNAs. Moderna and Pfizer have together pledged to deliver (mostly Pfizer and mostly through the US) some 250m vaccine doses to COVAX in 2021 for delivery to less developed countries. If we go to half-doses that becomes 500m doses–a life saver. And recall these points made earlier:

Judging by neutralizing antibodies, a 50 ug dose of, for example, Moderna looks to be more effective than standard dosing of many other vaccines including AZ and J&J and much better than others such as Sinovac. Thus alternative dosing is a way to *increase* the quality of vaccine for many people.

A 50 ug dose vaccine available today is much higher quality than a 100 ug dose vaccine available one year from now.

If we have the will, we can increase vaccine supply very rapidly.

Fractional Dosing Study in Brazil

Fiocruz, the Brazilian public health institute, will test half doses of the AstraZeneca vaccine. Not much information available yet. From a Google Translate article.

BANDNews: Fiocruz, in partnership with the government of Espírito Santo, is going to carry out a study with the application of half a dose of the Astrazeneca vaccine to the entire population of the municipality of Viana, in Greater Vitória.

The city has about 35 thousand inhabitants.

The immunization will take place on Sunday, June 13, and residents will be able to choose whether they want to participate in the study.

According to the state secretary of Health, Nésio Fernandes, there is already evidence of the effectiveness of the application of half a dose of the vaccine in immunization against Covid-19.

If the experience is successful, it will be possible to double the number of people vaccinated in the country with the immunizing agent produced by Fiocruz.

See my previous posts on fractional dosing for why this is very important.

Hat tip: Cisco Costa.

Fractional Dosing Trials Now!

Fractional dosing has the potential to massively increase the supply of COVID vaccine. The Moderna Phase I clinical trial and Pfizer Phase I/II trials already indicated a substantial immune response with smaller doses but the vaccine companies are under-incentivized to run additional fractional dosing trials (they won’t gain trillions, at best they will gains billions and might even lose some profit) and governments and private organizations are not picking up the ball. There are just two small trials underway that I am aware of:

N.B. now that we know that the vaccines work. we don’t need to study every dosage for efficacy against the virus. Instead of efficacy studies we can study how the vaccine is working in the body compared to those fully immunized, immunogencity trials (which is what the above trials are doing) and then use data and theory to infer effectiveness. If we felt it necessary to study effectiveness, human challenge trials would be ideal in this situation as you can study gradually smaller doses with little risk to the patients. But given the urgency, immunogenicity trials should provide enough information to make decisions on the ground. To limit risk, one could do a half-dose on the second dose or one could do a half-dose in people under the age of 50. Both of these regimens would still create significant increases in supply. Recall that in 2018, facing a yellow fever epidemic and a shortage of vaccine, Brazil used 1/5th doses to break the epidemic.

There are no guarantees but the world is ignoring a potential trillion dollar bill lying on the sidewalk.

Hat tip for discussion: Witold and Amrita.

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.

Alternative Dosing

Close-up medical syringe with a vaccine.

Alternative dosing is finally getting some attention. This story in Nature recounts some of the recent arguments and evidence:

Two jabs that each contained only one-quarter of the standard dose of the Moderna COVID vaccine gave rise to long-lasting protective antibodies and virus-fighting T cells, according to tests in nearly three dozen people1. The results hint at the possibility of administering fractional doses to stretch limited vaccine supplies and accelerate the global immunization effort.

Since 2016, such a dose-reduction strategy has successfully vaccinated millions of people in Africa and South America against yellow fever2. But no similar approach has been tried in response to COVID-19, despite vaccine shortages in much of the global south.

“There’s a huge status quo bias, and it’s killing people,” says Alex Tabarrok, an economist at George Mason University in Fairfax, Virginia. “Had we done this starting in January, we could have vaccinated tens, perhaps hundreds, of millions more people.”

…Sarah Cobey, an infectious-disease researcher at the University of Chicago in Illinois and a co-author of a 5 July Nature Medicine commentary supporting dose ‘fractionation’, disagrees about the need for time-consuming data collection.

“We shouldn’t wait that long,” she says. “People are dying, and we have historical precedent for making very well-reasoned guesses that we think are going to save lives.”

…According to a modelling study published by Tabarrok and other economists, such an approach would reduce infections and COVID-linked deaths more than current policies.

Addendum: The reason for doing the modeling study is precisely to take into account variants like Delta. Our modeling suggests that even with efficacy significantly lower than that suggested by Figure 1 in our paper, alternative doses of more effective vaccines would still provide significant reductions in mortality, even when new variants dominate. The benefits derive from vaccinating more quickly.

The Most Important Act of the Last Two Decades?

A good case can be made that Project Bioshield is the most important piece of legislation passed in the last twenty years. Passed under President Bush in 2004, Project Bioshield’s primary goal was to create advance market commitments to purchase countermeasures for chemical, biological, radiological or nuclear agents (CBRN). Several billion dollars have been spent in this area promoting anthrax and smallpox vaccines and various antitoxins for botulism and nuclear threats. The record on these advance market commitments is mixed with some notable failures.

The second thing the act did is to reduce some paperwork requirements on purchases and research funding. Those seem fine although the simplified procedure is itself too complex and the amounts such simplified procedures apply to are too small, e.g.

The Project Bioshield Act authorizes the HHS Secretary to use an expedited award process for grants, contracts, and cooperative agreements related to CBRN countermeasure R&D Activity, if the Secretary deems a pressing need for an expedited award exists. The authority is limited to awards of $1.5 million or less.

The third aspect of the act was not considered a big deal at the time but is the one that has proved to be the most important. Project Bioshield created the Emergency Use Authorization (EUA). In other words, prior to 2004 the FDA had no clear legislative authority to authorize an unapproved vaccine, drug or device. Without Project Bioshield and the EUA procedure the FDA might have eventually found some way to authorize vaccines before full approval. Britain, for example, used a temporary authorization procedure. Or the FDA might have sped up full approval but given the FDA’s lethargic record it’s easy to imagine that this would have taken months longer than the EUA process. As a result, the EUA procedure created by Project Bioshield probably saved 100,000 or more lives.

Important Addendum: It’s also worth mentioning that the EUA procedure doesn’t just apply to approvals it also allows changes in dosage and labeling. Susan Sherman, the senior attorney with the HHS Office of the General Counsel, noted in 2009 that a drug that had been approved for individual health in a non-emergency might have to be used very differently for public health in an emergency and that the EUA process could be used to adjust to these differences:

“You can change the labeling. You can change the information. You can change the dosage. You can give it to populations for which wasn’t approved.” She continued, “In some sense we had to match up in practice a public health response where you might not have the precise labeling that your physician would prescribe to you. There are a lot of variables that are necessary for the public health responders that don’t necessarily match what the approved drug would look like if you just went to your physician and got it because you had that illness.

In other words, the EUA process was made to allow for procedures such as fractional dosing. It’s too late for fractional dosing in the United States (but we should use it for boosters) but fractional dosing remains a vital tool to deal with the global shortage of vaccines.

Self Recommending Links

1. I had a fun and wide-ranging conversation with Jonah Goldberg on the Remnant. We covered the economy, immigration, cyborgs and the Baumol effect among other topics.

2. Tim Harford covers fractional dosing at the FT:

The concept of a standard or full dose is fuzzier than one might imagine. These vaccines were developed at great speed, with a focus on effectiveness that meant erring towards high doses. Melissa Moore, a chief scientific officer at Moderna, has acknowledged this. It is plausible that we will come to regard the current doses as needlessly high.

3. The Brunswick Group interviews me:

Act like you’re in a crisis. That has been economist Alex Tabarrok’s advice since the start of the COVID-19 pandemic. Tabarrok was among the earliest and loudest voices arguing for urgency and risk-taking when it came to increasing rapid testing, investing in vaccine capacity, and employing flexible vaccine dosing. In hindsight, he has been proven regularly right when most health experts were wrong.

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.

Cold Storage No Longer a Constraint

Yahoo: With little fanfare, the U.S. Food and Drug Administration gave Pfizer permission this week to store its COVID-19 vaccine in a typical refrigerator for one month — freeing the vaccine from the need to be shipped in cumbersome boxes stuffed with dry ice.

Among authorized COVID-19 vaccines, Pfizer’s vaccine was notorious for its ultra-cold storage requirements. Now, as the only vaccine authorized for children ages 12 to 17, this new flexibility could dramatically accelerate the effort to vaccinate America’s teens and adolescents.

Pfizer spent millions on its cold storage technology and now discovers that it isn’t strictly necessary–that wasn’t a mistake, Pfizer did the right thing–but it’s a good reminder of how new this technology is and also how the clinical trial decisions are not written in stone.

Straussian take: Investigate fractional dosing.

India’s Pandemic and the World

Shruti Rajagopalan is right, helping India isn’t just about India.

India’s role in the global pandemic is unique. The developing world is counting on affordable Indian vaccine-makers such as Serum Institute of India Pvt. Ltd. for their supplies. With India now reserving virtually all its doses for domestic use, those countries will have to wait even longer to be vaccinated. And if the pandemic disrupts production at Indian pharmaceutical companies, it could affect crucial non-Covid medications as well. Half the world’s children have been vaccinated by Serum Institute.

The Biden administration can do two things to help. The first is to ease restrictions on critical exports, imposed under the Defense Production Act to prioritize the needs of U.S. companies.

Vaccine production requires very specific, medically approved inputs, which are difficult to substitute quickly in the middle of a pandemic. Currently, U.S. producers must secure permission before exporting such things as special sterile filters, disposable bags for cell cultures, cell culture media and single-use tubing. The embargo has led to major bottlenecks. Serum Institute says that without those inputs, it may not be able to deliver the 160 million vaccine doses it had planned to produce next month.

Second, the U.S. should immediately share doses from its own supply of Oxford-AstraZeneca and Johnson & Johnson vaccines.

I have three things to add. First, I have already noted the foreign policy implications which weigh strongly in favor of taking a more active role in the world pandemic.

Second, India should move immediately to delay the second dose of the AZ vaccine to 12 weeks. The federal government has already recommended a 6-8 week schedule, as this improves efficiency of the AstraZeneca (Covishield) vaccine, but many people so fear shortages that they are getting a less-effective second dose at four weeks. An enforced 12 week schedule would improve efficiency and might also reassure people that there will be supplies in 12 weeks.

Third, and this is more speculative, but the rising pandemic in India provides an opportunity to test fractional dosing of the Pfizer and Moderna vaccines in a real world setting. There is currently a small-scale Belgian trial testing Moderna at 50 mcg and Pfizer at 20 mcg. We already have reasonable information that 50 mcg of Moderna induces a robust immune response in adults. The mRNA vaccines wouldn’t work in all of India but would be fine in the cities and perhaps there is an opportunity for an exchange similar to what Israel promised to get early supplies.

My Congressional Testimony

I thought the meeting went well. I made four points.

  • It is not too late to do more.
  • We should invest in nasal and oral vaccines.
  • We should vaccinate the world.
  • We should stretch doses through fractional dosing and delaying the second dose, this will be important to vaccinate the world quickly.

One observation. Lots of people are talking about vaccine hesitancy but I am one of the few people who have been talking about nasal and oral vaccines which are the only really solid approach to the issue that I have seen.

My best line:

The unvaccinated are the biggest risk for generating mutations and new variants. You have heard of the South Africa and Brazilian variants, well the best way to protect your constituents from these and other variants is to vaccinate South Africans and Brazilians.

I also got in the last word in Q&A when discussing the pause of J&J:

For the rest of the world it is important to underline that it is most important to get vaccinated now. Use the AstraZeneca vaccine, use the Johnnson & Johnson vaccine…don’t wait for Moderna or Pfizer, it is going to take too long…start your vaccination program early…vaccinate as quickly as possible, that is the route to health and wealth.

See Western Warnings Tarnish Vaccines the World Badly Needs for the beginnings of a disaster. Note that if J&J and AZ are tarnished or knocked out of the vaccine arsenal then dose stretching and investing in more capacity are going to be even more important.

I also submitted five excellent and important pieces to Congress:

Canadian statement on delaying the second dose.

National Advisory Committee on Immunization (NACI) Canada. 2021. “COVID-19 Vaccine Extended Dose Interval for Canadians: NACI Recommendation.” Government of Canada. March 3, 2021. https://www.canada.ca/en/public-health/services/immunization/national-advisory-committee-on-immunization-naci/rapid-response-extended-dose-intervals-covid-19-vaccines-early-rollout-population-protection.html.

Value of vaccine capacity and additional investments.

Castillo, Juan Camilo, Amrita Ahuja, Susan Athey, Arthur Baker, Eric Budish, Tasneem Chipty, Rachel Glennerster, et al. 2021. “Market Design to Accelerate COVID-19 Vaccine Supply.” Science, February. https://doi.org/10.1126/science.abg0889.

Efficacy of the first dose from NEJM.

Skowronski, Danuta, and Gaston Serres De. 2021. “Letter to the Editor on Safety and Efficacy of the BNT162b2 MRNA Covid-19 Vaccine.” New England Journal of Medicine, February 17, 2021. https://doi.org/10.1056/NEJMc2036242.

Overview of dose stretching policies (with links in the online version).

Tabarrok, Alex. 2021. “What Are We Waiting For?” Washington Post, February 12, 2021, sec. Outlook. https://www.washingtonpost.com/outlook/2021/02/12/first-doses-vaccine-rules-fda/

A plan to vaccinate the world.

Agarwal, Ruchir, and Tristan Reed. 2021. “How to End the COVID-19 Pandemic by March 2022” SSRN. 2021. https://documents.worldbank.org/en/publication/documents-reports/documentdetail/181611618494084337/how-to-end-the-covid-19-pandemic-by-march-2022

The whole thing is here. My written testimony is here.

Atul Gawande and Zeke Emanuel Now Support Delaying the Second Dose

Many people are coming around to First Doses First, i.e delaying the second dose to ~12 weeks. Atul Gawande, for example, tweeted:

As cases and hospitalizations rise again, we can’t count on behavior alone reversing this course. Therefore, it’s time for the Biden admin to delay 2nd vax doses to 12 weeks. Getting as many people as possible a vax dose is now urgent.

Now urgent??? Yes, I am a little frustrated because the trajectory on the new variants was very clear. On January 1, for example, I wrote about The New Strain and the Need for Speed (riffing off an excellent piece by Zeynep Tufekci).  Still, very happy to have Gawande’s voice added to the cause. Also joining Gawande are the power trio of Govind Persad, William F. Parker and Ezekiel J. Emanuel who in an important op-ed write:

If we temporarily delay second doses …that is our best hope of quelling the fourth wave ignited by the B.1.1.7 variant. Because we did not start this strategy earlier, it is probably too late for Michigan, New York, New Jersey and the other Northeastern states. But it might be just in time for the South and California — the next places the more infectious strain will go if historical patterns repeat.

…Drug manufacturers selected the three- or four-week interval currently used between doses to rapidly prove efficacy in clinical trials. They did not choose such short intervals based on the optimal way of using the vaccines to quell a pandemic. While a three- or four-week follow-up is safe and effective, there is no evidence it optimizes either individual benefit or population protection.

…Some complain that postponing second doses is not “following the science.” But the scientific evidence goes far beyond what was shown in the original efficacy trials. Data from the United Kingdom, Israel and now the Centers for Disease Control and Prevention shows that first doses both prevent infection and reduce transmission. In people with prior infection, experts are beginning to recognize that a second dose could provide even less benefit. Following the science means updating policies to recognize new evidence rather than stubbornly maintaining the status quo.

Emanuel is on Biden’s COVID-19 task force so consider this op-ed running the flag up the flagpole. I predict Topol will fall next.

I would be surprised, however, if the US changes course now–too many people would then ask why didn’t we do this sooner?–but dose stretching is going to be important for the rest of the world. Why aren’t we doing more to investigate fractional dosing? Even if we went to half-doses on the second dose–the full second dose appears to be strong–that would still be a significant increase in total supply.

Addendum: I have argued for sending extra doses to Michigan and other hot spots such as NJ. Flood the zone! The Biden administration says no. Why? Production is now running well ahead of distribution as more than 50 million doses have been delivered but not administered. It would be a particularly good idea to send more single-shot J&J to reach hard to reach communities–one and done.

From the Comments, On FDF

Sure and Tom Meadowcroft have been hitting it out of the ballpark in the comments sections. Two examples.

Sure:

Protocol was made to serve man, not man to serve the protocol.

The reason we have protocols is because we need to weight the harms of waiting without a treatment against the harms that happen if the treatment is counterproductive in some unforeseen manner.

We can, normally, pretty easily measure the benefit side: count up the mortality and morbidity for the illness in question. The risk side is harder so we developed tests and processes to elucidate those: RCTs, literature reviews, regulatory oversight, mandatory waiting periods. At the end of the day though, the whole process is just one giant test to measure the likely harm of a new entity.

So when is a test worth doing? After all I do not order an MRI for every patient even though I could find a lot of early stage cancers that way.

..GSW to the abdomen with crashing bp with minimal response to volume? Straight to the OR. No matter the results of the CT scan they are still getting opened to stop the bleeding.

…So now we look at the vaccine approval process and methods to stretch doses. Pre-test probability that vaccines work? Inordinately high after passing Phase II. Odds that we hit on the precise optimal timing regimen on the first go? Nil.

The likelihood ratios for RCTs and approval mechanisms are powerful. But we are talking thousands of deaths per day. The odds that these tests will remotely alter management decisions is nil. It is malpractice to delay life saving treatment on tests exceedingly unlikely to change management decisions.

And remember the UK is not seeing horrid outcomes for doing this for a while now. A lot of theoretical failure mechanisms are now off the table.

Science is wholly about building a reliable model that accurately predicts future outcomes of current actions. While doing the actual experiment is the gold standard for knowledge acquisition, it is not the only option and in cases like this pandemic is not sufficiently better than past data to merit waiting.

As far as the regulators. I work with some of them directly. They are not overburdened to anywhere near the degree that the frontline clinicians have been hit. When I ask them to explain their cost benefit calculations, they have none. Not I cannot follow them. Not I disagree with them. They have done not an iota of math to justify their course of action.

Sorry, but I believe in evidence based medicine, not eminence based medicine. If you as a regulator cannot explain to me in technical terms the math behind your decision process, even if only back of the envelope, you are not worth putting in charge.

Approve all the vaccines, FDF, fractional dosing trials, and first dose followed by variolation trials should all be done now. It is was [what] the math demands.

Also this from Tom Meadowcroft:

Scientific researchers search for the truth. Medical clinicians use limited data balance cost and benefits in the face of uncertainty to save the most lives.

When searching for the truth, it is important to have high standards of statistical significance, integrity, and patience, because credibility and a reputation for integrity is everything. Every academic knows that a retracted paper or an accusation of playing fast and loose with statistics can be the death knell for a career. As a result it is prudent to be very certain before publishing. Public health officials, particularly those in charge of approving vaccines, dread the possibility that a vaccine that will be given to millions of healthy people, often children, to prevent diseases where death is rare, which could harbor some flaw that causes a hundred avoidable deaths; they seek the highest standards of proof of safety and efficacy before approving such a vaccine.

But a pandemic is not a search for truth, and a COVID vaccine administered in the midst of a pandemic is very different than a measles vaccine administered to 2-year-olds. The pandemic makes these decisions for FDF or for vaccine approvals into clinical decisions, where health professionals should be balancing the certain benefit of reducing the thousands of daily deaths against the uncertain cost of the possibilities of harmful side-effects and uncertain details of efficacy (when does immunity kick in, how long does it last, how valuable is a booster) that additional months of testing and trials would reveal more clearly.

Public health researchers, academics for the most part, lack the ability (and courage) to make the sort of cost/benefit analysis with necessarily limited data that clinical physicians make every day in examination rooms. Any good clinician, faced with the citizenry of a country as their patient, would have opted for FDF, the AZ vaccine, and quite likely reduced doses by the start of the year. Because we are stuck with academics and administrators as our decision makes, unable to see beyond their usual routine of searching for the truth and protecting their reputations, thousands more will die.

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