The US Food and Drug Administration on Saturday issued an emergency use authorisation for a Johnson & Johnson-developed coronavirus vaccine, approving the use of the drug compound in individuals 18 years of age and older.
"After a thorough analysis of the data, the FDA's scientists and physicians have determined that the vaccine meets the FDA's expectations for safety and effectiveness appropriate for the authorisation of a vaccine for emergency use", said Peter Marks, director of the FDA's Centre for Biologics Evaluation and Research.
The clearance marks the third coronavirus vaccine greenlighted in the United States, with the Pfizer-BioNTech and Moderna vaccines approved by the FDA earlier.
The Johnson & Johnson vaccine, produced by the Belgium-headquartered pharmaceutical company Janssen, is administered as a single dose.
"The vaccine was approximately 77% effective in preventing severe/critical COVID-19 occurring at least 14 days after vaccination and 85% effective in preventing severe/critical COVID-19 occurring at least 28 days after vaccination", the FDA noted, referring to the effectiveness of the vaccine under emergency standards.
The United States remains the nation worst hit by the ongoing coronavirus pandemic, with over 28.5 million cases and 511,000 related fatalities registered, according to Johns Hopkins University data.