Now is not the time to experiment with changing the two-dose schedule set for the Pfizer and Moderna Covid-19 vaccines, Dr. Nancy Messonnier, the director of the National Center for Immunization and Respiratory Diseases at the US Centers for Disease Control and Prevention, said in conversation with the Journal of the American Medical Association on Friday.
Outside factors such as emerging variants make it difficult to try and extend the time between doses right now, Messonnier said.
“The vaccines have been studied and approved, authorized, recommended as a two-dose schedule. Our programs are built on that. We’ve communicated that to the public,” she said. “I just don’t think that there is enough science yet to tell us that it’s a moment to change what we know to be an effective regimen."
“For me right now, it’s the wrong moment to dial back. We’re looking at the science carefully,” Messonnier said, adding that this and other questions will be discussed Monday at a meeting of the CDC's vaccine advisers.