On September 22, 2021, the U.S. Food and Drug Administration (FDA) granted emergency use authorization for the Pfizer-BioNTech COVID-19 vaccine for use as a single booster dose administered at least six months after completion of the primary series in individuals aged 65 and older, individuals aged 18–64 at high risk for severe COVID-19, and individuals aged 18–64 whose frequent institutional or occupational exposure to SARS-CoV-2 puts them at high risk for serious complications of COVID-19 or severe COVID-19.
The booster dose is authorized for administration to those individuals at least six months following completion of their primary series and may be given at any point after that time. The authorization applies only to the Pfizer-BioNTech COVID-19 vaccine.
To support the emergency use authorization of a single booster dose, FDA analyzed safety and immune response data from a subset of participants from the original clinical trial of the Pfizer-BioNTech COVID-19 vaccine. The data assessed immune responses of approximately 200 participants aged 18–55 who received a single booster dose approximately six months after their second dose.
Safety was evaluated in 306 participants aged 18–55 and 12 participants aged 65 or older who were followed for an average of more than two months. The most common side effects that clinical trial participants who received the booster dose reported were pain, redness and swelling at the injection site, fatigue, headache, muscle or joint pain, and chills. Swollen lymph nodes in the underarm were observed more frequently following the booster dose than after the primary two-dose series.
FDA approved the Pfizer-BioNTech COVID-19 vaccine, now marketed as Comirnaty, on August 23, 2021, for the prevention of COVID-19 caused by SARS-CoV-2 in individuals aged 16 years and older.
Healthcare professionals should report all serious adverse events they suspect to be associated with the use of any medicine and device to FDA’s MedWatch Reporting System or by calling 800-FDA-1088.