Feb. 24 (UPI) -- Federal regulators said Wednesday that the COVID-19 vaccine developed by Johnson & Johnson has a favorable safety profile and appears to protect about two-thirds of the people who receive it -- a key step that indicates the vaccine will likely become the third approved for use in the United States.
The Food and Drug Administration issued an analysis that supports Johnson & Johnson's clinical study findings for the vaccine.
The vaccine, produced by subsidiary Janssen, is different than the two already being distributed in the United States from Pfizer and Moderna, in that it is adenovirus-based rather than using messenger RNA.
The Johnson & Johnson vaccine also requires only a single dose and doesn't need to be constantly stored at freezing temperatures, advantages that experts believe could increase vaccinations nationwide.
"The analysis supported a favorable safety profile with no specific safety concerns," the FDA wrote of the vaccine in its assessment.
The FDA report verified the company's previous finding that the vaccine was effective in about 66% of all trial participants. Efficacy varied in all three regions the vaccine was tested -- the United States (72%), Latin America (66%) and South Africa (57%) -- and researchers said the trials also included the South African variant strain.
The company said last month the vaccine was about 85% effective in preventing severe cases of COVID-19. It asked for FDA approval earlier this month.
Wednesday's FDA assessment came two days before the agency's vaccine committee is scheduled to meet and decide whether to recommend emergency approval. If approval is given Friday, the FDA would then decide whether to grant emergency use authorization, a step that would need to be confirmed by the Centers for Disease Control and Prevention.
If the remaining hurdles are cleared, the Johnson & Johnson vaccine would become the third vaccine available in the United States.
To date, about 82 million doses of Pfizer and Moderna vaccines have been distributed nationwide and 65 million doses have been administered, according to the CDC.
In the United States, more than a half-million people have died of the coronavirus disease.