If an actual COVID-19 infection occurs after dose #1 of COVID vaccine but prior to dose #2, how does that impact the timing of dose #2? 10-day interval post 'recovery' as indicated by CDC, extending optionally out to 90 days? Should more time be given to allow for immune recovery and response ala the 28 days recommended as the minimum interval between dosing?

Provided an individual has recovered from the COVID-19 infection, that is completed the recommended isolation period, (for most people, 10 days from onset of symptom onset or if asymptomatic, 10 days from a positive test or up to 20 days if severe disease or immunocompromised)  the timing of the second dose of the vaccine should not be delayed. The current recommendation for the Pfizer-BioNTech vaccine is that the second dose should be administered 21 days after the first and for the Moderna vaccine, 28 days later.  It is noted that if it is not possible to schedule the second vaccination when indicated, it can be administered up to 6 weeks (42 days) after the first dose. There is currently limited data on efficacy of mRNA COVID-19 vaccines administered beyond this window. If the second dose is administered beyond 42-day intervals, there is no need to restart the series.1

Delaying the initial dose for 90 days following infection is an option that may allow expanded access to others. However, deferring the second dose of a series does not expand access for others, because a subsequent dose cannot be assured for patients who receive another patient’s deferred second dose as their initial dose. 

The only situation where the second vaccination should be delayed is if monoclonal antibodies were administered as part of the treatment for the infection, in which case the recommendation is to delay the second dose of the vaccine for 90 day from completion of the antibody treatment until more is known about whether there might be any interference of the antibody therapy with vaccine-induced immune responses. A prior vaccination should not affect treatment decisions including the use of monoclonal antibodies, convalescent plasma, antiviral treatment, or corticosteroid administration) or the timing of such treatments.

Individuals who experience anaphylaxis after the first dose of COVID-19 vaccination should be instructed not to receive additional doses and referred to an allergist-immunologist for appropriate work-up and additional counseling. 2,3,4


  1. Interim Clinical Considerations for Use of mRNA COVID-19 Vaccines Currently Authorized in the United States. https://www.cdc.gov/vaccines/covid-19/info-by-product/clinical-considerations.html 
  2. Management of Anaphylaxis at COVID-19 Vaccination Sites. (2021). Retrieved January 30, 2021, from https://www.cdc.gov/vaccines/covid-19/clinical-considerations/managing-anaphylaxis.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fvaccines%2Fcovid-19%2Finfo-by-product%2Fpfizer%2Fanaphylaxis-management.html 
  3. COVID, C., & Team, R. (2021). Allergic Reactions Including Anaphylaxis After Receipt of the First Dose of Pfizer-BioNTech COVID-19 Vaccine—United States, December 14–23, 2020. Morbidity and Mortality Weekly Report, 70(2), 46.
  4. Prince-Guerra, J. L., Almendares, O., Nolen, L. D., Gunn, J. K., Dale, A. P., Buono, S. A., ... & Bower, W. A. (2021). Allergic reactions including anaphylaxis after receipt of the first dose of Moderna COVID-19 vaccine—United States, December 21, 2020–January 10, 2021.

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The Forum does not necessarily represent an official ACOEM position. The Forum is intended for health professionals and is not intended to provide medical or legal advice, including illness prevention, diagnosis or treatment, or regulatory compliance. Such advice should be obtained directly from a physician and/or attorney. Questions are answered with the best available data or recommendations at the time.