Immune response, side effects, and safety of the BA.1-adapted BNT162b2 vaccine in 18- to 55-year-olds with or without previous BNT162b2 COVID-19 vaccination

Declarations. Conflict of Interest: David Fitz-Patrick reports grant support from Pfizer, Moderna, and AstraZeneca. Leon F. Fouché, Essack Mitha, and Mookho Malahleha report no conflicts of interest. Federico Mensa and Ӧzlem Türeci are BioNTech employees and may hold stock or stock options. Uǧur Sahin is a BioNTech employee, may hold stock or stock options, and holds relevant patents. Kayvon Modjarrad and Kena A. Swanson are Pfizer employees, may hold stock or stock options, and are inventors on patents and patent applications related to the COVID-19 vaccine. All other authors are Pfizer employees and may hold stock or stock options. Ethical Approval: This study was conducted in accordance with the protocol and consensus ethical principles derived from international guidelines, including the Declaration of Helsinki Council and CIOMS International Ethical Guidelines, applicable ICH GCP Guidelines, and other applicable laws and regulations, including privacy laws. All participants provided written informed consent before enrollment.