More than two months after its last COVID-19 vaccine authorization, the FDA authorized for emergency use a one-shot vaccine from Janssen Biotech Inc., a Johnson & Johnson pharmaceutical company, on Feb. 27.
Unlike the Pfizer/BioNTech and Moderna vaccines, which use an mRNA design, the Johnson & Johnson shot uses a harmless adenovirus — a type of virus that typically causes the common cold — modified with the genetic material for SARS-CoV-2 to trigger an immune response. The Johnson & Johnson vaccine has the advantages of being one shot, not two, and being stored at regular refrigeration temperatures for up to three months. The Pfizer and Moderna two-shot vaccines can only be kept at refrigerator temperatures for five or 30 days, respectively.
Overall, J&J reported 66.1% efficacy globally in preventing moderate to severe COVID-19 in adults 28 days or more after vaccination, and an efficacy of 85.4% in preventing severe or critical COVID-19. The efficacy was similar across demographics including age, race and ethnicity.
The vaccine had 100% efficacy in preventing COVID-19 that would require medical intervention — meaning hospitalization, ICU admission, mechanical ventilation or a life support machine — 28 days or more after vaccination.