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.