Important update: Healthcare facilities
CDC has updated select ways to operate healthcare systems effectively in response to COVID-19 vaccination. Learn more
To maximize protection from the Delta variant and prevent possibly spreading it to others, get vaccinated as soon as you can and wear a mask indoors in public if you are in an area of substantial or high transmission.
UPDATE
Given new evidence on the B.1.617.2 (Delta) variant, CDC has updated the guidance for fully vaccinated people. CDC recommends universal indoor masking for all teachers, staff, students, and visitors to K-12 schools, regardless of vaccination status. Children should return to full-time in-person learning in the fall with layered prevention strategies in place.

COVID-19 Vaccines That Require 2 Shots

COVID-19 Vaccines That Require 2 Shots

CDC now recommends that people aged 65 years and older, residents in long-term care settings, and people aged 50–64 years with underlying medical conditions should receive a booster shot of Pfizer-BioNTech’s COVID-19 Vaccine at least 6 months after completing their Pfizer-BioNTech primary series. Other groups may receive a booster shot based on their individual risk and benefit. Learn more.

Learn more about booster shots.

What You Need to Know

  • If you receive a Pfizer-BioNTech or Moderna COVID-19 vaccine, you will need 2 shots to get the most protection.
  • COVID-19 vaccines are not interchangeable. If you received a Pfizer-BioNTech or Moderna COVID-19 vaccine, you should get the same product for your second shot.
  • You should get your second shot even if you have side effects after the first shot, unless a vaccination provider or your doctor tells you not to get it.
  • If you have a weakened immune system due to other diseases or medications, you can receive a COVID-19 vaccine if you have not had a severe or immediate allergic reaction to any of the ingredients in the vaccine.
  • People with moderately to severely compromised immune systems should receive an additional dose of mRNA COVID-19 vaccine after the initial 2 doses.

Timing of Your Second Shot

The timing between your first and second shots depends on which vaccine you received. If you received the:

Pfizer-BioNTech COVID-19 vaccine
Get your second shot 3 weeks (or 21 days) after your first

Moderna COVID-19 vaccine
Get your second shot 4 weeks (or 28 days) after your first

People with moderately to severely compromised immune systems should receive an additional dose of mRNA COVID-19 vaccine after the initial 2 doses.

You should get your second shot as close to the recommended 3-week or 4-week interval as possible. However, your second dose may be given up to 6 weeks (42 days) after the first dose, if necessary. You should not get the second dose early. ​There is currently limited information on the effectiveness of receiving your second shot earlier than recommended or later than 6 weeks after the first shot.

However, if you do receive your second shot of COVID-19 vaccine up to 4 days before or at any time after the recommended date, you do not have to restart the vaccine series, and you can be considered fully vaccinated. This guidance might be updated as more information becomes available.

Cases of myocarditis and pericarditis in adolescents and young adults have been reported more often after getting the second dose than after the first dose of one of the two mRNA COVID-19 vaccines, Pfizer-BioNTech or Moderna. These reports are rare and the known and potential benefits of COVID-19 vaccination outweigh the known and potential risks, including the possible risk of myocarditis or pericarditis.

Scheduling Your Second Shot

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  • Planning for your second shot is important.
  • If you need help scheduling your vaccination appointment for your second shot, contact the location that set up your first appointment.
  • If you are having trouble or have questions about using a vaccination management or scheduling system, reach out to the organization that enrolled you in the system. This may be your state or local health department, employer, or vaccination provider.​
  • Scheduling an appointment for your second shot at the time you get your first shot is recommended, but not required.
  • If you need to get your second shot in a location that is different from where you received your first shot (for example, if you moved to a different state or attend school in a different state), there are several ways you can find a vaccine provider for your second dose.

Vaccination Card and Your Second Shot

At your first vaccination appointment, you should have received a vaccination card that tells you what COVID-19 vaccine you received, the date you received it, and where you received it. Bring this vaccination card to your second vaccination appointment.

  • If you did not receive a COVID-19 vaccination card at your first appointment, contact the vaccination provider site where you got your first shot or your state health department to find out how you can get a card.
  • If you have lost your vaccination card or don’t have a copy, contact your vaccination provider directly to access your vaccination record.
    • If you cannot contact your vaccination provider directly, contact your state health department’s immunization information system (IIS). You can find state IIS information on the CDC website. Vaccination providers are required to report COVID-19 vaccinations to their IIS and related systems.
    • If you enrolled in v-safe or VaxText after your first vaccine dose, you can access your vaccination information using those tools.
    • If you have made every effort to locate your vaccination information, are unable to get a copy or replacement of your vaccination card, and still need a second shot, talk to a vaccination provider.
  • Bring your vaccination card with you to your second shot appointment so your provider can fill in the information about your second dose.
  • Keep your vaccination card in case you need it for future use. Consider taking a picture of your vaccination card after your second shot appointment as a backup copy.

CDC does not maintain vaccination records or determine how vaccination records are used, and CDC does not provide the CDC-labeled white COVID-19 vaccination record card to people. These cards are distributed to vaccination providers by state health departments.

Please contact your state health department if you have additional questions about vaccination records. Your local or state health department can also provide more information about the laws or regulations in your area.

When You Are Fully Vaccinated

People are considered fully vaccinated:

  • 2 weeks after their second shot in a 2-dose series, like the Pfizer or Moderna vaccines, or
  • 2 weeks after a single-shot vaccine, like Johnson & Johnson’s Janssen COVID-19 Vaccine

COVID-19 vaccines are not interchangeable. If you received a Pfizer-BioNTech or Moderna COVID-19 vaccine, you should get the same product for your second shot.

You are not fully vaccinated if:

  • it has been less than 2 weeks since your 1-dose shot
  • it has been less than 2 weeks since your second shot of a 2-dose vaccine
  • you still need to get your second dose of a 2-dose vaccine