By Dorit Rubinstein Reiss
Faced with limited COVID-19 vaccine doses and the ever-mounting toll and strain of the pandemic, a new debate has emerged as to the best strategy for allocating the vaccines.
Both COVID-19 vaccines authorized for emergency use in the U.S., which are produced by Pfizer/BioNTech and Moderna, have been studied under two-dose clinical trials. The two-dose regime is thought to accord a more robust immune response against COVID-19.
In the U.K., however, due to concerns about the shortage of COVID-19 vaccines, the government has deviated from established protocols. First, it decided to delay (but not omit) the administration of the second dose of the available vaccines, in order to increase the number of people getting at least one dose; second, it decided to allow mixing and matching of doses across vaccine types.
The United States is considering following the U.K. and moving to give more first doses, at the cost of delaying completion of the series.
Experts are sharply divided on whether that is a good or bad idea.