Table 4.

Summary of key clinical trials for Pfizer, Moderna, and Johnson & Johnson SARS-CoV-2 Vaccines^9,29,38.

Key clinical trials for Pfizer, Moderna, and Johnson & Johnson vaccine candidates
Pfizer–BioNTech mRNA COVID-19 Vaccine BNT162b2	Phase 3 trial began July 27, 2020, with over 43,000 participants and concludes November 18, 2020. Results show 95.0% efficacy against serious COVID-19 infection, defined as requiring hospitalization. FDA approved Emergency Use Authorization (EUA) for Pfizer vaccine on December 11, 2020. Full FDA approval for vaccine in the US on August 23, 2021.
Moderna mRNA-1273 COVID-19 Vaccine	Phase 3 trial began July 2020, called the COVE study. The COVE trial showed 94.1% efficacy in protecting against symptomatic infections and showed no deviation in cohorts with risk factors for severe COVID-19 infections. FDA approves EUA for Moderna vaccine on December 18, 2020.
Johnson & Johnson Adenovirus Type 26 COVID-19 Vaccine	Ensemble Phase 3 trial began September 7, 2020, with 44,000 participants. Ensemble trial shows 66.1% protection against moderate COVID-19 infection and 85.4% protection against severe infection with no hospitalizations or deaths in participants. FDA approves EUA for Johnson & Johnson vaccine on February 27, 2021.