On Sept. 9, 2020, Pfizer and BioNTech announced that they had submitted an amended protocol to the FDA to expand the enrollment of their Phase 3 pivotal COVID-19 vaccine trial to up to approximately 44,000 participants which also allows for the enrollment of new populations.

The proposed expansion would allow the companies to further increase trial population diversity, and include adolescents as young as 16 years of age and people with chronic, stable HIV (human immunodeficiency viruses), Hepatitis C, or Hepatitis B infection, as well as provide additional safety and efficacy data.