Clear Up Confusion About Additional COVID-19 Vaccine Doses

Patients will ask you about additional COVID-19 vaccine doses.

Emphasize that COVID-19 vaccination remains very effective in reducing severe disease, hospitalization, and death.

And almost all severe COVID-19 cases are in UNvaccinated patients.

But explain that overall protection against mild to moderate disease is declining...likely due to waning immunity and the Delta variant.

For moderately or severely immunocompromised patients, continue to give a third dose of an mRNA COVID-19 vaccine (Moderna or Pfizer-BioNTech's Comirnaty)...at least 28 days after the second dose.

It's an "additional dose"...not a "booster"...since these patients likely had an inadequate immune response after the initial series.

Define "immunocompromised" as you do for other vaccines. Get specifics in our Vaccinating Immunocompromised Patients chart.

For example, look for patients on cancer treatment...with HIV and CD4 count under 200 cells/mm3...or on high-level immunosuppressants (Humira, prednisone at least 20 mg/day for 14 days, tacrolimus, etc).

Use the same mRNA COVID-19 vaccine for the additional dose. If it's not available, don't turn a patient away...give the other mRNA vaccine.

Booster doses are different. They're meant to maintain protection in patients who likely had an adequate response initially.

Clarify that timing and eligibility of boosters continues to be a moving target due to quickly evolving data.

For now, give a Pfizer-BioNTech booster at least 6 months after the second dose to patients 65 and older, long-term care residents, and those 50 to 64 with underlying medical conditions (diabetes, obesity, etc).

And consider a booster for patients ages 18 to 49 with these underlying conditions...and adults with occupational exposure (healthcare workers, teachers, etc). But evidence is less clear for these groups.

Stay tuned for guidance on Moderna and Johnson & Johnson/Janssen boosters...and whether you can mix and match.

Don't base decisions about additional OR booster doses on antibody tests. These aren't designed to assess protection against COVID-19.

For anyone getting a third dose, educate that side effects seem similar to after the second dose. Continue to encourage patients to report side effects using "v-safe."

Refer to our COVID-19 Vaccines chart and Communicating About COVID-19 Vaccination FAQ for the latest immunization details.

Key References

  • www.cdc.gov/coronavirus/2019-ncov/vaccines/recommendations/immuno.html (9-23-21)
  • www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-authorizes-additional-vaccine-dose-certain-immunocompromised (9-23-21)
  • www.fda.gov/news-events/press-announcements/fda-authorizes-booster-dose-pfizer-biontech-covid-19-vaccine-certain-populations (9-23-21)
  • www.cdc.gov/vaccines/covid-19/clinical-considerations/covid-19-vaccines-us.html (9-23-21)
Pharmacist's Letter. October 2021, No. 371003



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