The United States Food and Drug Administration on Friday granted emergency use approval to the coronavirus vaccine developed by pharmaceutical company Pfizer and its German partner BioNTech. This is the first vaccine candidate to have been authorised by the country to combat the spread of Covid-19, which has taken more than 2.90 lakh American lives.

The vaccine had shown to be 95% effective in preventing the disease in a late-stage trial. The first inoculations are expected to happen early next week.

United States President Donald Trump, however, said that the first shot would be administered in less than 24 hours. He called the approval of the vaccine a “medical miracle”, adding that the vaccine will be free for all Americans. “The pandemic may have begun in China, but we are ending it here, in America,” Trump said in a televised address released on Twitter.

The outgoing president added that governors would decide who would receive the shots first in their states. “We want our senior citizens, health care workers and first responders to be first in line,” he said. “This will quickly and dramatically reduce deaths and hospitalisations.”

Before vaccinations can begin, a US Centers for Disease Control and Prevention immunisation advisory committee still must vote to recommend the vaccine, and the CDC must accept that recommendation, according to CNN. The Advisory Committee on Immunization Practices is scheduled to meet on Saturday.

The FDA said the vaccine can be given to people aged 16 and older. Healthcare workers and elderly people in long-term care facilities are expected to be the main recipients of a first round of 2.9 million doses, according to The New York Times.

The decision came two days after an advisory panel of the Food and Drug Administration approved with an overwhelming majority the emergency use of the vaccine. The panel, comprised of independent scientific experts, infectious disease doctors and statisticians, voted 17 to 4 that the known benefits of the vaccine outweighed the risks of taking the shot for individuals aged 16 and older. One member of the panel abstained from voting.

An emergency use authorisation means that the US drug regulator will allow the vaccine to be used for emergency cases, but is short of a full approval. Pfizer would have to file a separate application for its vaccine to be fully licensed by the FDA. On Thursday, the company said it intended to do so by April next year.

“The FDA’s authorization for emergency use of the first Covid-19 vaccine is a significant milestone in battling this devastating pandemic that has affected so many families in the United States and around the world,” said the drugs agency commissioner Stephen M Hahn. “Today’s action follows an open and transparent review process that included input from independent scientific and public health experts and a thorough evaluation by the agency’s career scientists to ensure this vaccine met FDA’s rigorous, scientific standards for safety, effectiveness, and manufacturing quality needed to support emergency use authorisation.”

The Pfizer/BioNTech vaccine was first approved in Britain on December 2, and the UK residents began receiving the shots on Tuesday. It was the first clinically authorised, fully tested immunisation effort in the world. Canada also authorised the vaccine and expects to start inoculations next week. In addition, Saudi Arabia, Mexico and Bahrain have also approved the vaccine.

The vaccine uses messenger mRNA technology to introduce the body to the spike protein found on the outside of the coronavirus to provoke an immune response. It requires two doses, administered three weeks apart.

The vaccine comes with complex distribution challenges as it must be shipped and stored at -70 Celsius, requiring specialised ultra-cold freezers. Moderna’s vaccine, which showed 94.5% efficacy in final trials, employs the same technology but does not need to be stored at sub-Arctic temperatures.