An investigational COVID-19 vaccine developed by Janssen Pharmaceuticals appears to be safe and effective at preventing moderate and severe COVID-19 in adults, according to an interim analysis of Phase III clinical data. The vaccine, called Ad.26.COV2.S or JNJ-78436725, requires only a single injection and can be stored in a refrigerator for months.
The interim analysis assessed 468 cases of symptomatic COVID-19 among 44,325 adult volunteers in Argentina, Brazil, Chile, Colombia, Mexico, Peru, South Africa, and the United States.
The investigational vaccine was reportedly 66% effective overall at moderate and severe COVID-19 28 days post-vaccination among all volunteers, including those infected with an emerging viral variant.
Moderate COVID-19 was defined as laboratory-confirmed SARS-CoV-2 plus either one of the following: evidence of pneumonia; deep vein thrombosis, difficulty breathing; abnormal oxygen saturation or a respiratory rate equal to or greater than 20; or two or more signs or symptoms suggestive of COVID-19, such as cough, sore throat, fever or chills.
Severe COVID-19 was defined as laboratory-confirmed SARS-CoV-2 plus evidence of clinical signs at rest indicative of severe systemic illness, respiratory failure, shock, significant organ dysfunction, hospital intensive care unit admission or death.
Geographically, the level of protection for the combined endpoints of moderate and severe disease varied: 72% in the United States; 66% in Latin American countries; and 57% in South Africa, 28 days post-vaccination. The investigational vaccine was reportedly 85% effective in preventing severe/critical COVID-19 across all geographical regions. No deaths related to COVID-19 were reported in the vaccine group, while five deaths occurred in the placebo group were related to COVID 19. Overall, there were 16 deaths in the placebo group, and three deaths in the vaccine group.