Important developments on COVID-19 vaccine booster shots

On August 18, 2021, the U.S. Department of Health and Human Services and medical experts released a joint statement recommending the administration of mRNA COVID-19 (Pfizer-BioNTech or Moderna) vaccine booster shots. According to the statement, booster doses could ensure vaccine durability and maximize protection against COVID-19 disease. The joint statement says that the federal government will begin providing mRNA COVID-19 vaccine booster shots on September 20, 2021, subject to the evidence evaluation and determination of the safety and effectiveness by FDA and CDC’s Advisory Council on Immunization Practices (ACIP).

Key points

  • Evidence indicates that the mRNA COVID-19 vaccines’ efficacy in preventing mild and moderate disease declines over time. The duration of protection is uncertain.
  • Despite this, the vaccines remain more than 90% effective in preventing hospitalizations and remain extremely effective in preventing severe disease and death—even as the Delta variant circulates rapidly.
  • The federal government is prepared to begin offering booster doses beginning September 20, 2021, to anyone who received their second dose 8 or more months prior to that date.
  • But the launch is dependent on the approval of FDA and CDC-ACIP, who are conducting and reviewing evaluations of booster doses’ safety and effectiveness.

Access three new MMWR reports to learn more

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

  • Researchers observed no decline in vaccine effectiveness in the 24 weeks after a group of 1,129 patients received 2 doses of an mRNA vaccine. The vaccine was 86% effective in the 2 to 12 weeks after vaccination and 84% effective at 13 to 24 weeks.
  • Vaccine effectiveness was sustained among groups at risk for severe COVID-19.
  • Ongoing monitoring is needed as new SARS-CoV-2 variants emerge.
  • To reduce hospitalization, all eligible persons should be offered COVID-19 vaccination.

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

  • Between May 3, 2021, and July 25, 2021, the overall age-adjusted COVID-19 vaccine effectiveness against hospitalization in New York was relatively stable (91.9%–95.3%).
  • However, the overall age-adjusted vaccine effectiveness against infection for all New York adults declined from 91.7% to 79.8%.
  • These findings support the implementation of multicomponent approach to controlling the pandemic. This multicomponent approach should center on vaccination and include other prevention strategies, such as masking and physical distancing.

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

  • Early observational studies among nursing home residents showed mRNA vaccines to be between 53% and 92% effective against SARS-CoV-2 infection.
  • Two doses of mRNA vaccines were 74.7% effective against infection among nursing home residents early in the vaccination program (March–May 2021).
  • During June and July 2021, when the Delta variant spread rapidly, mRNA vaccine effectiveness declined significantly to 53.1%.
  • An additional dose of COVID-19 vaccine might be considered for nursing home and long-term care facility residents to optimize a protective immune response.

Key questions and answers

What do we know about who will be eligible for mRNA vaccine boosters?

According to the joint statement, COVID-19 vaccine boosters—if FDA and CDC-ACIP authorize and recommend them—will be available to individuals who finished their two-dose series 8 or more months prior to the September 20, 2021, launch date. Residents of nursing homes and health care workers received the vaccines in the first phase of rollout, in December 2020 and January 2021, and would therefore be positioned to receive a third dose.
Evidence shows the vaccines’ efficacy in preventing infection has declined significantly in individuals in nursing homes, who received the vaccine in the earliest stages of rollout. The factors driving diminished protection are unclear; possibilities include waning immunity over time, the proliferation of the Delta variant, relaxed recommendations for masking and physical distancing, or a combination of these.
Health care workers also began receiving COVID-19 vaccines in the earliest phases of rollout and could also be at risk for diminished protection.

Does the joint statement affect the recent ACIP recommendations about additional doses of mRNA COVID-19 vaccines for immunocompromised patients?

The August 18 joint statement has no effect on ACIP’s recommendation that moderately to severely immunocompromised patients receive a third dose of an mRNA vaccine. The information remains accurate and current.
Of note, the guidance about immunocompromised patients refers to a “third dose,” while the HHS joint statement refers to “boosters.” These terms are not synonymous.
According to CDC, immunocompromised individuals will need a three-dose series (a two-dose series plus an additional dose, rather than a two-dose series alone) to achieve a sufficient immune response. A “booster” dose following a two-dose series would maintain a sufficient immune response.

Should pharmacies and other immunizers begin delivering booster shots?

The administration of booster mRNA vaccine doses will not begin until September 20, 2021, and even that date is not definite: FDA and CDC-ACIP will conduct research and evaluation to ensure there is sufficient evidence that booster doses are safe and effective. Until they approve and recommend booster doses, the September 20 date is tentative. ACIP will meet on Tuesday, August 24. We can expect more details after that.
In addition to creating a window for FDA and CDC-ACIP investigation and approval, the delay until September 20 is intended to allow immunizers time to plan for the ordering and administration of booster doses. Providers should begin to plan for implementation of booster-dose administration, which could include collaborating with skilled nursing facilities and developing strategies to serve non-mobile patient populations.
Providers should also plan for patient flow management, vaccine documentation, and billing processes.
Patients will not need to receive their booster dose from the same provider they received their initial doses.

Does the joint statement apply to the Johnson & Johnson (J&J) vaccine?

There is currently no published evidence that patients who received the J&J vaccine will need a booster dose to ensure continued protection from COVID-19 disease. The joint statement, however, noted that patients who received the J&J vaccine likely will require a booster to ensure protection remains strong, and that the issue is under investigation. The federal government expects more data to emerge in the coming weeks and will inform the public as soon as more is known.
Pharmacies should not administer J&J booster doses until federal agencies authorize them. Pharmacies that begin administering J&J boosters before they receive approval put themselves out of compliance with their COVID-19 vaccine provider agreement and pose increased risk of liability from which the PREP Act would otherwise shield them.