US approves Johnson & Johnson's single-dose anticovid vaccine
The US Food and Drug Administration (FDA) on Saturday finally cleared Johnson & Johnson's single-dose covid-19 vaccine for emergency use, the third to get the green light in the country.
"This is exciting news for all Americans, and an encouraging development in our efforts to end this crisis," US President Joe Biden said in a statement released by the White House.
Biden, however, cautioned that "this fight is not yet over."
"As we celebrate today's news, I ask all Americans: continue to wash your hands, continue to keep your social distance, and continue to wear masks... Count on keeping this battle going in the months ahead," he said.
Approval was imminent after an FDA vaccine advisory committee backed emergency approval of Johnson & Johnson's covid-19 vaccine, which is expected to be approved for distribution this weekend.
The United States, the country hardest hit by the pandemic in the world, now has more than 28.5 million cases and more than 510,000 deaths, according to the latest independent count by Johns Hopkins University.
Although the average daily number of new cases has fallen sharply in recent days to below 70,000 a day, down from nearly 300,000 at the start of the year, authorities continue to warn of the danger, especially as new strains emerge.
"Now is not the time to relax restrictions. While we have seen large reductions in cases and hospital admissions in the past six weeks, these declines come after the largest spike we have seen in the pandemic," Rochelle Walensky, director of the Centers for Disease Control and Prevention (CDC), told a news conference on Friday.
According to the FDA's vaccine advisory committee, Johnson & Johnson's vaccine candidate is safe and sufficiently effective against SARS-CoV-2 in people over 18 years of age, leaving only formal confirmation of its emergency authorisation, which could be finalised as early as Saturday.
Tests of J&J's vaccine have shown it to be 66% effective against the coronavirus, below the 94-95% effectiveness of existing vaccines, but with an 86% ability to stave off severe disease, hospitalisations and deaths, which could be enough to protect the population.
J&J's vaccine will join the Pfizer/BioNTech and Moderna vaccines, which have been administered since late December in the US and have been used to immunise healthcare workers, emergency workers and the elderly, and are now slowly becoming available to the rest of the population.
The inclusion of the first single-dose vaccine should help speed up the vaccination campaign by not requiring a second dose after three weeks, as is the case with the Pfizer and Moderna injections, although Johnson & Johnson has said it is considering annual reminders.
J&J's vaccine does not require the extreme cold temperatures in storage as Pfizer and Moderna do, as it is not based on messenger RNA, like its predecessors, but on instructions encoded in a DNA strand transmitted into the cell in an adenovirus, a technique less prone to spoilage.
For this reason, it can be stored for up to three months at temperatures of 2 to 8 degrees Celsius, something that would reduce the complexity of the supply chain and scenes such as those experienced in some parts of the country, where emergency vaccines were distributed to the population after problems with freezers.
Since the end of December, when the first of the vaccines was authorised, the US has administered more than 68 million doses, meaning that just over one in five Americans have already been immunised with the first of the two required doses.
