The single shot vaccine was developed at the Janssen Pharmaceutical Companies and has passed the Phase 3 clinical trials having met all primary and key secondary endpoints. Towards the end of January, clinical trials of the vaccine showed promising results. The trials were conducted in the United States, Latin America and South Africa, and after 28 days, none of the vaccinated participants who developed COVID-19 had to be hospitalised. According to the FDA analysis, the efficacy of the Johnson & Johnson vaccine against moderate to severe/critical Covid-19 across all geographic areas was 66.9% at least 14 days after the single-dose vaccination and 66.1% at least 28 days after vaccination, reported CNN. “There were no specific safety concerns identified in subgroup analyses by age, race, ethnicity, medical comorbidities, or prior SARS-CoV-2 infection,” the analysis stated.