The US Food and Drug Administration (FDA) will begin a review of a third dose in all adults of the Pfizer/BioNTech and Moderna COVID-19 vaccines to be given eight months after their second dose. Pending review and approval by the FDA and dosing recommendations by the Centers for Disease Control and Prevention (CDC), booster rollout could begin on September 20, 2021. The FDA and the US Department of Health and Human Services have also provided an update regarding a booster dose for Johnson & Johnson’s (J&J) COVID-19 vaccine.

“Based on our latest assessment, the current protection against severe disease, hospitalization, and death could diminish in the months ahead, especially among those who are at higher risk or were vaccinated during the earlier phases of the vaccination rollout,” said US government health officials in a joint statement on August.18, 2021. “For that reason, we conclude that a booster shot will be needed to maximize vaccine-induced protection and prolong its durability.”

Issuing the statement were: Dr. Rochelle Walensky, Director of the CDC; Dr. Janet Woodcock,  FDA’s Acting Commissioner; Dr. Vivek Murthy, US Surgeon General; Dr. Francis Collins, Director of the National Institutes of Health; Dr. Anthony Fauci, Chief Medical Advisor to President Joe Biden and Director of the National Institute of Allergy and Infectious Diseases; Dr. Rachel Levine, Assistant Secretary for Health; Dr. David Kessler, Chief Science Officer for the COVID-19 Response; and Dr. Marcella Nunez-Smith, Chair of the COVID-19 Health Equity Task Force.

The officials said they have developed a plan to begin offering these booster shots this fall (fall 2021) subject to FDA conducting an independent evaluation and determination of the safety and effectiveness of a third dose of the Pfizer/BioNTech and Moderna mRNA COVID vaccines and CDC’s Advisory Committee on Immunization Practices (ACIP) issuing booster dose recommendations based on a review of the evidence. Pending this review, health officials are preparing to offer booster shots for all Americans beginning the week of September 20, 2021 and starting eight months after an individual’s second dose. President Joe Biden confirmed this timeline and process for review in an August 18, 2021 press briefing.

Pfizer and BioNTech have submitted Phase I data, part of their Phase I/II/III clinical trial program, to the FDA to support the evaluation of a third, or booster dose, of the companies’ COVID-19 vaccine, BNT162b2, for future licensure. The companies report that these data will also be submitted to the European Medicines Agency (EMA) and other regulatory authorities in the coming weeks (as reported on August 16, 2021).

The companies say Phase III results evaluating the third dose are expected shortly and will be submitted to the FDA, the EMA and other regulatory authorities globally. In the US, Pfizer and BioNTech plan to seek licensure of the third dose via a supplemental biologics license application (BLA) in individuals 16 years of age and older, pending FDA approval of the primary BLA submitted in May 2021.

Additionally, in a joint statement, the HHS and the FDA anticipate that booster shots will likely be needed for J&J’s COVID-19 vaccine. “Administration of the J&J vaccine did not begin in the US until March 2021, and we expect more data on J&J in the next few weeks,” the agencies said in their August 18, 2021 joint statement. “With those data in hand, we will keep the public informed with a timely plan for J&J booster shots as well.”

In July (July 2021), J&J shared data demonstrating that its single-shot COVID-19 vaccine generated strong, persistent immune activity against the rapidly spreading Delta variant and other highly prevalent SARS-CoV-2 viral variants. Interim results from a Phase I/IIa study also showed that the durability of the immune response was strong, with no waning for at least eight months, the length of time that had been evaluated to date (as reported on August 19, 2021).

J&J says it is engaging with the FDA, the CDC, and other health authorities and will share new data shortly regarding boosting with its COVID-19 vaccine.

Booster shots for immunocompromised authorized

The recommendation for booster COVID-19 vaccine doses for adults follows an amendment the FDA made last week (August 12, 2021) to the emergency use authorizations (EUAs) for the COVID vaccines of Pfizer/BioNTech and Moderna to allow for the use of an additional booster dose in certain immunocompromised individuals.

An additional dose was authorized for solid organ transplant recipients or those who are diagnosed with conditions that are considered to have an equivalent level of immunocompromise. The CDC’s Advisory Committee on Immunization Practices is scheduled to meet Friday, August 20, 2021 to discuss further clinical recommendations regarding immunocompromised individuals. As of press time (August 20, 2021), there has been no update to these recommendations.

Moderna reported that a recent trial of 120 individuals who had undergone solid organ transplant procedures (heart, kidney, kidney-pancreas, liver, lung, pancreas) demonstrated that a third dose of its COVID-19 vaccine improved immune response compared to placebo. In the study, the third dose of mRNA-1273 was generally well tolerated.

Source: White House, US Food and Drug Administration (joint statement), US Food and Drug Administration (EUA amendment), US Department of Health and Human Services, Moderna, Pfizer, BioNTech, and Johnson & Johnson