The United States Food and Drug Administration on Saturday approved emergency-use authorisation for a single-dose coronavirus vaccine developed by pharmaceuticals company Johnson & Johnson. The vaccine became the third one, after those developed by Pfizer-BioNTech and Moderna, to receive the approval in the US.

“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 authorization of a vaccine for emergency use (sic),” Peter Marks, the director of the drug regulator’s Center for Biologics Evaluation and Research, said.

FDA Commissioner Janet Woodcock said that the approval will expand the availability of vaccines in the country in the fight against the pandemic.

The authorisation allowed the vaccine to be distributed in the US for use in individuals of 18 years of age or older. Unlike the other two approved vaccines, the Johnson & Johnson vaccine is administered as a single dose.

US President Joe Biden also appreciated the approval granted to the vaccine, adding a word of caution that it was “not the time to relax”, PTI reported. “We know that more people that get vaccinated, the faster we will overcome the virus, get back to our friends and loved ones, and get our economy back on track,” Biden said.

Results from a trial of about 44,000 participants show that the new vaccine was 66% effective in preventing moderate-to-severe coronavirus infections, the FDA release stated. It also said the most common reactions were injection site pain, headache, fatigue and aches and pains. The vaccine can remain stable for at least three months at normal refrigerator temperatures.

Apart from the dosage regimen, the Johnson & Johnson vaccine also differs in the way it creates resistance against the virus. The Pfizer-BioNTech and Moderna vaccines use new messenger RNA [Ribonucleic acid] technology to create an immune response, while this vaccine involves a more conventional approach, using a common cold virus to introduce coronavirus proteins into cells to trigger an immune response.