Both the Moderna and Pfizer-BioNTech vaccines require 2 shots, depending on which vaccine you get, this will take place 21 or 28 days after the first injection. But if your second shot does not happen in that window Dr. Kavita Patel, an internal medicine physician and HuffPost medical contributor, says not to panic.
“The CDC has gone on record to state that you can safely get the second dose about 42 days out for Moderna and Pfizer ― you can also get it a couple of days earlier as well,” she explains, noting it is best to get then second does on your scheduled day, and if rescheduling is necessary to make it as close to the original date as possible.
Currently, it is not known if there is a period of time that is deemed "too late" for the second dose, as this situation has yet to be studied.
Dr. Patel adds, "If it’s more than 90 days, I would imagine some might recommend restarting."
Patients should be getting both doses from the same manufacturer, but HuffPo notes that the CDC has said in rare instances a second dose from a different manufacturer could be used, but stresses this should only be "considered a last-resort option" if the patient for some reason is sure that getting a second dose of the original shot is not possible.
Learn more about the possible side effects of the COVID-19 vaccine and how to prepare before you go in for your first shot.