![The second dose is the same as the first dose but the Pfizer and Moderna vaccines are not interchangeable.. [Evgenia Parajanian / Shutterstock]](https://npr.brightspotcdn.com/dims4/default/8321106/2147483647/strip/true/crop/3000x2003+0+0/resize/840x560!/format/webp/quality/90/?url=http%3A%2F%2Fnpr-brightspot.s3.amazonaws.com%2Flegacy%2Fuploads%2F2021%2F4%2F16%2Fsecond%20dose.jpg)
What are your questions about the coronavirus vaccine?
ideastream's health team is answering as many questions as possible, with help from local experts in a range of fields. You can send us your questions with our online form, through our social media group, or call us at 216-916-6476. We'll keep the answers coming on our website and on the air.
Aubrey from Cleveland asks: “Is the second dose of the Pfizer or Moderna vaccine different than the first one?”
The second dose is the same as the first dose, but Pfizer and Moderna are not interchangeable. The person administering the vaccine needs to know the brand of the first dose.
So, providers will make sure they are giving you the same brand for your first and second dose, says MetroHealth’s Dr. David Margolius.
They’ll also make sure you are getting the second dose at the right time.
For Pfizer, the minimum time between the doses is 21 days, while for Moderna, the minimum amount of time between doses is 28 days.
According to the U.S. Centers for Disease Control and Prevention people should wait no more than 6 weeks between doses.
