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Moderna COVID-19 Vaccine Booster Dose Guidance

Moderna COVID-19 Vaccine Booster Dose Guidance

Dear COVID-19 Vaccine Providers,

On October 20, 2021, a Moderna COVID-19 Vaccine booster dose was authorized for specific populations listed below. The volume of a Moderna booster dose is .25mL.

Click here to read the full Moderna Booster Guidance Fact Sheet!

Booster Vaccination: One 0.25 mL dose

  • A booster dose may be administered intramuscularly at least 6 months after completing a primary series with the Moderna COVID-19 Vaccine to individuals:
    • 65 years of age and older
    • 18 through 64 years of age at high risk of severe COVID-19
    • 18 through 64 years of age with frequent institutional or occupational exposure to COVID-19

A single booster dose of the Moderna COVID-19 Vaccine (0.25 mL) may be administered as a heterologous (mix and match) booster dose following completion of primary vaccination with another authorized COVID-19 vaccine. The eligible population(s) and dosing interval for the mix and match booster dose are the same as those authorized for a booster dose of the vaccine used for primary vaccination.

Use of Multidose Vials of Moderna COVID-19 Vaccine

  • The Moderna COVID-19 Vaccine is supplied in two multiple-dose vial presentations:
    • A multiple-dose vial containing 5.5 mL
    • A multiple-dose vial containing 7.5 mL
  • Primary series doses of 0.5 mL and booster doses of 0.25 mL may be extracted from either vial presentation, preferentially using low dead-volume syringes and/or needles.
  • When extracting only primary series doses, depending on the syringes and needles used, a maximum of 11 doses (range: 10-11 doses) may be extracted from the vial containing 5.5 mL or a maximum of 15 doses (range: 13-15 doses) may be extracted from the vial containing 7.5 mL.
  • When extracting only booster doses or a combination of primary series and booster doses, the maximum number of doses that may be extracted from either vial presentation should not exceed 20 doses.
  • Do not puncture the vial stopper more than 20 times.
  • If the amount of vaccine remaining in the vial cannot provide a full dose of 0.5 mL or 0.25 mL, discard the vial and contents. Do not pool excess vaccine from multiple vials.

Thank you for keeping Philadelphia safe and healthy. If you have any questions, please email