- Previously received doses of COVID-19 vaccines that are FDA-approved, FDA-authorized or pre-qualified or listed for emergency use by WHO: Administer 1 age-appropriate dose of a 2024–2025 COVID-19 vaccine at least 8 weeks after the last COVID-19 vaccine dose (Table 1).
- Previously received doses of COVID-19 vaccines that are not FDA-approved, FDA-authorized, or prequalified or listed for emergency use by WHO: The doses do not count towards vaccination in the United States and these people are considered unvaccinated; initiate vaccination at least 8 weeks after the last COVID-19 vaccine dose (Table 1).
- Children ages 6 months–4 years and people who are moderately or severely immunocompromised
- Previously received doses of COVID-19 vaccines that are FDA-approved, FDA-authorized, or prequalified or listed for emergency use by WHO: The doses count towards vaccination in the United States; administer the number of age-appropriate doses of a 2024–2025 COVID-19 vaccine based on the schedule in Table 1 or Table 2.
- Previously received doses of COVID-19 vaccines that are not FDA-approved, FDA-authorized, or prequalified or listed for emergency use by WHO: The doses do not count towards vaccination in the United States and these people are considered unvaccinated; initiate vaccination at least 8 weeks after the last COVID-19 vaccine dose Table 1 or Table 2.
Special situation: If unable to determine if a previously received vaccine dose was a 2024–2025 COVID-19 vaccine, do not count the dose and follow guidance for administering a 2024–2025 COVID-19 vaccine dose.
Appendix B. Vaccine administration errors and deviations
The package insert or EUA fact sheet for healthcare providers and U.S. COVID-19 Vaccine Product Information should be referenced for detailed information on storage and handling, dosing and schedule, dose preparation, and administration of COVID-19 vaccines. The information provided below on managing vaccine administration errors should not be interpreted as a recommendation or promotion of unauthorized use of the vaccines.
For all vaccine administration errors:
- Inform the recipient of the vaccine administration error.
- Consult with the jurisdiction immunization program and/or immunization information system (IIS) to determine how the dose should be entered into the IIS.
- Determine how the error occurred and implement strategies to prevent it from happening again. A discussion on strategies to prevent errors can be found in Epidemiology and Prevention of Vaccine-Preventable Diseases (Pink Book). Additional resources can be found on CDC’s vaccine administration web page, including a job aid for preventing errors.
- Follow the revaccination guidance in the table below, using an age-appropriate COVID-19 vaccine product. Then continue with the recommended schedule for subsequent dose(s) unless otherwise noted in Table B.
Vaccinators should consult Reporting of vaccine adverse events for information on reporting to the Vaccine Adverse Event Reporting System (VAERS) after COVID-19 vaccination. To file an electronic report, see the VAERS website .
Table B. Interim recommendations for COVID-19 vaccine administration errors and deviations
- Incorrect site (i.e., site other than the deltoid muscle or vastus lateralis muscle)
- Do not repeat dose.
- Incorrect route (e.g., subcutaneous)
- Do not repeat dose.
- Inform the recipient of the potential for local and systemic adverse events.
- 2024-2025 mRNA vaccine administered to an unauthorized age group (recipients younger than age 6 months)
- If the first dose is administered 5 or more days before age 6 months, repeat the dose on or after the date the recipient reaches 6 months; space the repeat dose at least 4 weeks after the invalid dose.*
- 2024-2025 Novavax vaccine administered to an unauthorized age group (recipients ages 6 months–11 years)
- If part of a multidose initial vaccination series (i.e., children ages 6 months–4 years or people ages 6 months and older who are moderately or severely immunocompromised), count the dose; continue the series with a 2024-2025 mRNA vaccine; and space the next dose by at least the minimum interval (Table 1 and Table 2). † If the last dose in the series, no further doses are needed.
- For children ages 5–11 years who are not moderately or severely immunocompromised:
- If previously received 1 or more doses of any mRNA vaccine, no further doses are needed.
- If did not previously receive any doses of any mRNA vaccine, administer 1 dose of a 2024-2025 mRNA vaccine at least 4 weeks after the dose given in error. †
- Higher-than-authorized dose administered (e.g., incorrect dose volume, incorrect product resulting in higher-than-authorized dose)
- Do not repeat dose. ‡
- Lower-than-authorized dose administered (e.g., leaked out of the syringe, equipment failure, recipient pulled away, incorrect product resulting in lower-than-authorized dose)
- Repeat dose immediately (no minimum interval). †
- However, if a half-volume dose of vaccine is administered to a recipient recommended for the full volume, another half-volume dose can be administered on the same clinic day, and the 2 doses can count as 1 full dose.
- Dose administered after improper storage and handling (i.e., temperature excursion)
- Contact the manufacturer for information on the stability of the vaccine. § If the manufacturer does not have data to support the stability of the vaccine, repeat the dose immediately (no minimum interval). †
- Dose administered past the expiration/beyond-use date
- Repeat the dose immediately (no minimum interval). †
- Any COVID-19 dose administered prior to the minimum interval ¶
- Repeat dose. Space the repeat dose after the dose given in error by at least the minimum interval (Table 1 and Table 2). †
- mRNA vaccines from different manufacturers administered as part of an initial vaccination series
- See Interchangeability of COVID-19 vaccines for detailed guidance on completion of vaccination when doses from different manufacturers are used.
- If a previously completed 3-dose mRNA series did NOT include at least 1 dose of a 2024–2025 mRNA vaccine:
- For children ages 6 months–4 years who are not moderately or severely immunocompromised, administer 1 dose of a 2024–2025 mRNA vaccine at least 8 weeks after the last dose.
- For people ages 6 months and older who are moderately or severely immunocompromised, administer 1 dose of an age-appropriate 2024–2025 COVID-19 vaccine at least 8 weeks after the last dose.
- One dose of 2024–2025 mRNA vaccine and 1 dose of 2024–2025 Novavax vaccine (in any order) administered to previously unvaccinated recipient age 12 years and older
- For people who are not moderately or severely immunocompromised, no further doses needed.
- For people who are moderately or severely immunocompromised, administer 1 dose of any 2024–2025 vaccine (i.e., Moderna, Novavax, or Pfizer-BioNTech) at least 4 weeks after the last dose for a total of 3 doses.
- ONLY diluent administered (i.e., sterile 0.9% sodium chloride)
- Administer the authorized dose immediately (no minimum interval).
- No diluent, resulting in higher than authorized dose
- Do not repeat dose. Inform the recipient of the potential for local and systemic adverse events. ‡
- Incorrect diluent type (e.g., sterile water, bacteriostatic 0.9% sodium chloride)
- Repeat the dose immediately (no minimum interval). †
- Vaccine is mixed with too little diluent
- Do not repeat dose. Inform the recipient of the potential for local and systemic adverse events. ‡
- Vaccine is mixed with too much diluent
- Repeat dose immediately (no minimum interval). †
- Single-use vial of diluent is used to mix multiple vials of vaccine
- Do not repeat dose.
- See General Best Practice Guidelines for information on infection control and sterile technique.
- Vaccine is mixed with any diluent (i.e., any type or volume of diluent)
- Repeat the dose immediately (no minimum interval). †
* In addition to the minimum age, for children who are not moderately or severely immunocompromised, an 8-week interval between the invalid dose and the repeat dose might be optimal for some people as it might reduce the rare risk of myocarditis and pericarditis associated with mRNA (Moderna or Pfizer-BioNTech) COVID-19 vaccines and the potential for increased reactogenicity.
† For people ages 6 months–64 years who are not moderately or severely immunocompromised, an 8-week interval between the dose given in error and the repeat dose might be optimal for some people as it might reduce the rare risk of myocarditis and pericarditis associated with Moderna, Novavax, and Pfizer-BioNTech COVID-19 vaccines, particularly in males ages 12–39 years, and the potential for increased reactogenicity.
‡ If the administration error resulted in a higher-than-authorized vaccine dose, in general a subsequent dose may still be administered at the recommended interval. However, if local or systemic side effects following vaccination are clinically concerning (outside of the expected side effect profile) or are ongoing at the time of the subsequent dose, this dose might be delayed, but this decision should be assessed on a case-by-case basis.
§ As of the date of this update, current manufacturer contact information is:
- Pfizer-BioNTech: 1-877-VAX-CO19 (1-877-829-2619)
- Moderna: 1-866-MODERNA (1-866-663-3762)
- Novavax: 1-844-NOVAVAX (1-844-668-2829)
See the package inserts and EUA fact sheets for the most up-to-date manufacturer information.
¶ Vaccine doses administered up to 4 days before the minimum interval (i.e., grace period) may be counted and do not need to be repeated.
# See Interchangeability of COVID-19 vaccines for circumstances in which a COVID-19 vaccine from a different manufacturer may be administered; a VAERS report is not required in these circumstances.
