More on Alternative Dosing

Some quick comments in response to questions and discussion about my paper Could Vaccine Dose Stretching Reduce COVID-19 Deaths? (written with the all-star cast of Witold Więcek, Amrita Ahuja, Michael Kremer, Alexandre Simoes Gomes, Christopher M. Snyder and Brandon Joel Tan.

1) Any method of increasing vaccine supply will require other changes in the supply chain such as more needles. We think alternative dosing can increase supply quickly with the fewest supply chain disruptions.

2) If we had started Moderna with 50 ug dosing no one would be advocating for 100 ug dosing, thereby halving supply. Rather than “full” or “half-doses,” which bias thinking, we should talk about alternative dosing and ug.

3) 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.

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

5) There are substantial risks from following the current approach, as India and now parts of Africa illustrate. Alternative dosing has a very large upside but small downside since we could switch back to standard doses. For example, Great Britain and Canada delayed the second dose to 12 and 16 weeks respectively but have since reduced the dosing interval as more supplies have become available.

6) The greatest risk to immune escape comes from the unvaccinated. Alternative dosing protects not only those who are dosed but by reducing transmission also reduces risks to the unvaccinated.

7) The key question we face now is not whether there are objections and complications to alternative dosing (there are) the key question is what additional information, available quickly could resolve the most uncertainty? In other words, what can we learn soon that would most aid decision makers?

See the paper for details and also my previous post, A Half Dose of Moderna is More Effective Than a Full Dose of AstraZeneca.

Addendum: It should be clear that this isn’t about the United States, it is about getting high-quality vaccine to places that have little to none.