FDA On Vaccines: Don’t Mix And Match, No Half-Doses

Via press release from the FDA:

We have been following the discussions and news reports about reducing the number of doses, extending the length of time between doses, changing the dose (half-dose), or mixing and matching vaccines in order to immunize more people against COVID-19.

These are all reasonable questions to consider and evaluate in clinical trials. However, at this time, suggesting changes to the FDA-authorized dosing or schedules of these vaccines is premature and not rooted solidly in the available evidence.

Without appropriate data supporting such changes in vaccine administration, we run a significant risk of placing public health at risk, undermining the historic vaccination efforts to protect the population from COVID-19.

The available data continue to support the use of two specified doses of each authorized vaccine at specified intervals.

For the Pfizer-BioNTech COVID-19 vaccine, the interval is 21 days between the first and second dose. And for the Moderna COVID-19 vaccine, the interval is 28 days between the first and second dose.