How Many Doses Do I Need?
Stay Up to Date Resources

Updated Aug. 3, 2022

Find Out How Many Doses You Need to Stay Up to Date

You are up to date with your COVID-19 vaccines when you have received all doses necessary to complete your primary series and all boosters that are recommended for you. The overview below explains how many doses you need and when to get them based on your age and the vaccine you get, or use CDC’s booster tool to find out exactly what you need. If you have a moderately to severely compromised immune system, see If You Are Moderately or Severely Immunocompromised.

Fact Sheet: How Many Doses Do I Need?

Adults 18 and Older

Pfizer-BioNTech

Primary Series

2 doses 3 – 8 weeks apart

Booster(s)

Booster 1: Most people should receive one booster, preferably Pfizer or Moderna at least 5 months after the final primary dose
Booster 2: Ages 50 + should receive a second booster of Pfizer or Moderna at least 4 months after first booster

Moderna

Primary Series

2 doses 4 – 8 weeks apart

Booster(s)

Booster 1: Most people should receive one booster, preferably Pfizer or Moderna at least 5 months after the final primary dose
Booster 2: Ages 50 + should receive a second booster of Pfizer or Moderna at least 4 months after first booster

Novavax

Primary Series

Should be used only for those people who have never had a COVID-19 vaccine; 2 doses, 3 – 8 weeks apart

Booster(s)

The Novavax vaccine is not authorized for use as a booster dose.

Johnson & Johnson (Janssen)*

Primary Series

1 dose

Booster(s)

Booster 1: Most people should receive one booster, preferably Pfizer or Moderna at least 2 months after a Johnson & Johnson vaccine
Booster 2: Most people should receive a second booster of Pfizer or Moderna at least 4 months after first booster

*The FDA announced further limitations on the authorized use of the Johnson & Johnson vaccine on May 5, 2022 after determining that the risk of thrombosis with thrombocytopenia syndrome (TTS) warranted limiting use of the vaccine. The CDC also supports these recommendations. Learn more about when the Johnson & Johnson vaccine is recommended.


Youth 12 – 17

Pfizer-BioNTech

Primary Series

2 doses 3 – 8 weeks apart

Booster(s)

Booster 1: Should receive one booster of Pfizer at least 5 months after the final primary dose

Moderna

Primary Series

2 doses 4 – 8 weeks apart

Booster(s)

Not recommended for members of this age group who received Moderna for their primary series.


Babies and Children Under 11

Pfizer-BioNTech

Primary Series

Age 5 – 11: 2 doses 3 – 8 weeks apart
Age 6 months – 4 years: 3 doses; second dose is given 3 – 8 weeks after first dose and third dose is given at least 8 weeks after second dose

Booster(s)

Age 5 – 11: Booster 1: Should receive one booster of Pfizer at least 5 months after the final primary dose
Age 6 months – 4 years: Boosters are not recommended at this time

Moderna

Primary Series

Age 6 – 11: 2 doses 4 – 8 weeks apart
Age 6 months – 5 years: 2 doses 4 – 8 weeks apart

Booster(s)

Not recommended for members of this age group who received Moderna for their primary series.


If You Are Moderately or Severely Immunocompromised

People who are moderately or severely immunocompromised should follow a separate schedule for their COVID-19 vaccine primary series and booster doses. People with a weakened immune system may be at greater risk for severe COVID-19 illness and their immune response to the vaccine may not be as strong as in other people. The overview below explains how many doses you need and when to get them based on your age and the vaccine you get, or use CDC’s booster tool to find out exactly what you need.

What Does it Mean to be Immunocompromised?

Individuals who meet the following criteria may benefit from additional doses of the vaccines:

  • Age 6 months and older
  • Currently receiving active cancer treatment for tumors or blood cancers
  • Received an organ transplant and are taking medicine to suppress the immune system
  • Received a stem cell transplant within the last two years or are taking medicine to suppress the immune system
  • Have moderate to severe primary immunodeficiency such as DiGeorge syndrome or Wiskott-Aldrich syndrome
  • Advanced or untreated HIV infection
  • Active treatment with high-dose corticosteroids or other drugs that may suppress the immune response

If you received the Johnson & Johnson COVID-19 vaccine, your second dose of vaccine should be an mRNA vaccine. This is different from the booster recommendation.

Please speak with your provider about your health conditions and to determine if an additional dose is appropriate for you.

Fact Sheet: How Many Doses Do I Need?

Adults 18 and Older

Pfizer-BioNTech

Primary Series

3 doses with second dose 3 weeks after first dose and third dose at least 4 weeks after second dose

Booster(s)

Booster 1: Preferably Pfizer or Moderna at least 3 months after the final primary dose
Booster 2: Pfizer or Moderna at least 4 months after first booster

Moderna

Primary Series

3 doses with second dose 4 weeks after first dose and third dose at least 4 weeks after second dose

Booster(s)

Booster 1: Preferably Pfizer or Moderna at least 3 months after the final primary dose
Booster 2: Pfizer or Moderna at least 4 months after first booster

Novavax

Primary Series

Should only be used for those people who have never had a COVID-19 vaccine; 2 doses with second dose 3 weeks after first dose

Booster(s)

The Novavax vaccine is not authorized for use as a booster dose.

Johnson & Johnson (Janssen)*

Primary Series

2 doses: first dose is Johnson & Johnson, second dose should be either Pfizer or Moderna at least 4 weeks after first dose

Booster(s)

Booster 1: Pfizer or Moderna at least 2 months after receiving a second dose of either Pfizer or Moderna to complete the primary series
Booster 2: Pfizer or Moderna at least 4 months after first booster

*The FDA announced further limitations on the authorized use of the Johnson & Johnson vaccine on May 5, 2022, after determining that the risk of thrombosis with thrombocytopenia syndrome (TTS) warranted limiting use of the vaccine. The CDC also supports these recommendations. Learn more about when the Johnson & Johnson vaccine is recommended.


Youth 12 – 17

Pfizer-BioNTech

Primary Series

3 doses with second dose 3 weeks after first dose and third dose at least 4 weeks after second dose

Booster(s)

Booster 1: Preferably Pfizer or Moderna at least 3 months after the final primary dose
Booster 2: Pfizer or Moderna at least 4 months after first booster

Moderna

Primary Series

3 doses with second dose 4 weeks after first dose and third dose at least 4 weeks after second dose

Booster(s)

Not recommended for members of this age group who received Moderna for their primary series.


Babies and Children Under 11

Pfizer-BioNTech

Primary Series

Age 5 – 11 years: 3 doses with second dose given 3 weeks after first dose and third dose at least 8 weeks after second dose
Age 6 months – 4 years: 3 doses; second dose is given 3 weeks after first dose and third dose is given at least 8 weeks after second dose

Booster(s)

Age 5 – 11 years: Booster 1: Should receive one booster of Pfizer at least 3 months after the final primary dose
Age 6 months – 4 years: Boosters are not recommended at this time

Moderna

Primary Series

Age 6 months – 11 years: 3 doses with second dose given 4 weeks after first dose and third dose given at least 4 weeks after second dose

Booster(s)

Not recommended for members of this age group who received Moderna for their primary series.


Which Vaccines You Can Get for Primary Series and Booster Doses

CDC does not recommend mixing and matching vaccines when receiving your primary series. You may choose a different vaccine for your booster. CDC recommends that people who are getting a booster dose get either Pfizer-BioNTech or Moderna (mRNA COVID-19 vaccines). Individuals may choose the Novavax vaccine for their primary series, but they should not mix and match with mRNA vaccines. Additionally, the Novavax vaccine is not authorized for use as a booster for anyone. The mRNA vaccines are preferred over Johnson & Johnson’s Janssen COVID-19 vaccine in most circumstances. Learn more


If You Have Had COVID-19

If you have recently had COVID-19, you may consider delaying receiving your vaccine (primary dose or booster) by three months from when your symptoms started or after receiving a positive test result if you had no symptoms.