The bottom line For now, youâre unlikely to have a choice. Medical experts say itâs important to take whichever vaccine is offered to you, and both the Pfizer and Moderna vaccines that are currently authorized in the U.S. have been shown to be highly effective at preventing disease. As vaccine supply increases and more options become available in the coming months and years, there may be more scope for doctors to recommend different types of shots for different populations. The details Currently, there is a little bit of wiggle room for people who are determined to get one vaccine over another. People who have registered for vaccination can try to call vaccine sites directly to find out whether they have Pfizer or Moderna shots. But many places donât inform people ahead of time about which vaccine they will get during the appointment.