The idea of modifying the authorized dosing or schedules of COVID-19 vaccines was premature and was not supported by the available data, stated the U.S. Food and Drug Administration.

The agency said that it had been following discussions and news reports about decreasing the number of doses, increasing the length of time between the doses, reducing the dose in half, or mixing and matching vaccines in a bid to vaccinate more people. While the questions were reasonable to consider, the agency stated that changing the FDA-authorized dosing or schedules of these vaccines at this time is premature and has no robust evidence available. In the absence of appropriate data supporting the changes in vaccine administration, there is a significant risk of placing public health at risk… (Reuters, January 5, 2021)