Pharmacy Practice

Plans Announced for Booster Doses for Previously Immunized

Published: August 18, 2021

Today, public health and medical experts from the Department of Health and Human Services announced the administration's plan to provide additional doses of mRNA COVID-19 vaccines for anyone previously fully immunized. Additional doses would be available the week of Sept. 20, pending authorization by the Food and Drug Administration and recommendation by the Centers for Disease Control & Prevention (CDC) Advisory Committee on Immunization Practices and allowing time for tribal, state, and local operationalization. 

The expectation is that an additional dose should be administered eight months after completion of the primary 2-dose series. The additional dose rollout will follow closely with phase 1 of the initial vaccine rollout with healthcare workers, nursing home staff and residents, and those over 65 years prioritized. The plan is exclusive to the mRNA COVID-19 vaccines at this time; however, data related to the need for boosters for those who received Johnson & Johnson’s Janssen COVID-19 vaccine is still being reviewed and plans will be released at a later date. 

Planning for additional booster doses comes after a review of data from three studies published by the CDC on vaccine efficacy (VE) against the SARS-CoV-2 variants. While vaccine protection remains high against severe disease, hospitalization, and death, modeling of the data reveals that as protection begins to wane and variants increase, those outcomes may worsen. In addition, data indicates that VE against infection prevention is decreasing.

During a White House briefing today, Rochelle Walensky, CDC director; Jeff Zients, White House COVID-19 response coordinator; Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases and chief medical adviser to the president; and U.S. Surgeon General Vivek Murthy emphasized that there needs to be continued, vigilant focus on increasing vaccination rates with the primary series. The new plan for additional doses is to take proactive steps to extend vaccine protection and stay ahead of the variants, officials said. President Biden will speak about the vaccination effort at 4:30 p.m. ET today. 

The CDC released three Morbidity and Mortality Weekly Reports that underscored the impact of the COVID-19 vaccination, including:

Sustained Effectiveness of Pfizer-BioNTech and Moderna Vaccines Against COVID-19-Associated Hospitalizations Among Adults — United States, March–July 2021. Study takeaways include:

  • Among all adults in New York state, overall effectiveness against new COVID-19 infections declined from about 92% to about 80%.
  • The decline in effectiveness against new infections coincides with the increase in the Delta variant in the United States, along with relaxation of masking and physical distancing recommendations.
  • The factors driving the apparent changes in vaccine effectiveness, including variations by age, are uncertain. The substantially increased infectiousness of the Delta variant might underpin its increased transmissibility and could potentially lead to reduced vaccine-induced protection against infection.

New COVID-19 Cases and Hospitalizations Among Adults, by Vaccination Status — New York, May 3–July 25, 2021. Study takeaways include:

  • Vaccine effectiveness against COVID-19 associated hospitalization was 86% during the first 2–12 weeks post-vaccination and 84% effective during the following 12-week period.
  • The vaccine was found to be 90% effective against COVID-19 associated hospitalizations for people without immunocompromising conditions.
  • For those with immunocompromising conditions, the vaccine was found to be only 63% effective against hospitalizations associated with COVID-19 (over the 24-week study). The CDC now recommends that people whose immune systems are moderately to severely compromised should receive an additional dose of mRNA COVID-19 vaccine at least 4 weeks after their second dose, for a total of three doses.
  • Widespread vaccination is a critical tool to reduce the risk of hospitalization due to COVID-19.


Effectiveness of Pfizer-BioNTech and Moderna Vaccines in Preventing SARS-CoV-2 Infection Among Nursing Home Residents Before and After Widespread Circulation of the SARS-CoV-2 B.1.617.2 (Delta) Variant — National Healthcare Safety Network, March 1–August 1, 2021. Study takeaways include:

  • Among nursing home residents, in the pre-Delta period two doses of mRNA vaccine were 75% effective against COVID-19 infections; but during the Delta period, mRNA vaccine effectiveness declined to 53%.
  • Investigators could not determine if the lowered vaccine effectiveness was caused by potential waning immunity, reduced protection against the Delta variant (that became the dominant strain within 6 months after vaccine rollout), or a combination of both factors.
  • Vaccination of nursing home residents, staff members, and visitors should be prioritized because residents remain at higher risk for COVID-19 despite vaccination.
  • A potential need for an additional vaccine dose exists among populations at higher risk of severe COVID-19 outcomes.

The American Medical Association created a provisional Current Procedural Terminology (CPT) code for the administration of a third dose of the Pfizer-BioNTech (0003A) and Moderna (0013A) COVID-19 vaccine. The Centers for Medicare and Medicaid Services (CMS) clarified that Medicare beneficiaries who qualify for an additional dose can receive it with no cost sharing for patients. CMS reimbursement for administration of an additional dose will be approximately $40 each. In addition, the National Council for Prescription Drug Programs (NCPDP) recently revised its NCPDP Emergency Preparedness Guidance to include additional dose considerations for COVID-19 vaccines. 

For additional resources from ASHP on the variants, visit for a patient-friendly article and graphics on understanding COVID-19 variants or check out our COVID-19 vaccine tracking table





Posted August 18, 2021

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