FDA statement on compliance with authorized dosing schedules for COVID-19 vaccines

Two different mRNA vaccines have now shown a remarkable 95% efficacy in preventing COVID-19 infection in adults. As the first round of vaccinees becomes eligible to receive their second dose, we want to remind the public of the importance of receiving COVID-19 vaccines according to how they have been authorized by the FDA to safely receive the level of protection observed in large randomized clinical trials that support its effectiveness.

We have been following discussions and news about reducing the number of doses, increasing the time interval between doses, changing the dose (half dose) or combining and combining vaccines to immunize more people against COVID-19. All of these are reasonable questions to be considered and evaluated in clinical studies. However, at this point, suggesting changes to the FDA-authorized dosage or regimens for these vaccines is premature and has no solid roots in the available evidence. Without appropriate data to support these changes in vaccine administration, we are at significant risk of putting public health at risk, undermining historic vaccination efforts to protect the COVID-19 population.

Available data continues to support the use of two specific doses of each vaccine authorized at specified intervals. For the Pfizer-BioNTech COVID-19 vaccine, the interval is 21 days between the first and the second dose. For the Modern COVID-19 vaccine, the interval is 28 days between the first and the second dose.

What we have seen is that data in companies’ submissions on the first dose are being commonly misinterpreted. In phase 3 studies, 98% of participants in the Pfizer-BioNTech study and 92% of participants in the Moderna study received two doses of the vaccine at an interval of three or four weeks, respectively. Participants who did not receive two doses of vaccine over an interval of three or four weeks were generally followed for a short period of time, so that we cannot conclude anything definitive about the depth or duration of protection after a single dose of the percentages vaccine. single dose reported by companies.

Using a single dose regimen and / or administering less than the dose studied in clinical trials without understanding the nature of the depth and duration of protection it provides is worrisome, as there is some indication that the depth of the immune response is associated with duration protection provided. If people do not really know how protective a vaccine is, there is the potential for harm because they can assume that they are fully protected when they are not and, consequently, change their behavior to take unnecessary risks.

We know that some of these discussions about changing the dosage or dose schedule are based on the belief that changing the dose or dosing schedule can help get more vaccine to the public more quickly. However, making such changes that are not supported by adequate scientific evidence can be counterproductive to public health.

We continually commit to making decisions based on data and science. Until vaccine manufacturers have data and science to support a change, we continue to strongly recommend that healthcare professionals follow the FDA-authorized dosing schedule for each COVID-19 vaccine.

The FDA, an agency of the United States Department of Health and Human Services, protects public health by ensuring the safety, efficacy and safety of human and veterinary drugs, vaccines and other biological products for human use and medical devices. The agency is also responsible for the security and protection of the supply of food, cosmetics, dietary supplements, products that emit electronic radiation and for the regulation of tobacco products.

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