Johnson & Johnson’s single-dose vaccine offers strong protection against severe COVID-19, according to an analysis released on Wednesday by US regulators that sets the stage for a final decision on a new and easy-to-use shot to help tame the pandemic.
The long-awaited shot could offer the nation a third vaccine option and help speed up vaccinations by requiring just one dose instead of two. Food and Drug Administration researchers confirmed that the vaccine overall is about 66% effective in preventing moderate to severe COVID-19 and about 85% effective against the most serious disease. The agency also said that J & J’s shot is safe.
The analysis is just one step in the FDA’s evaluation. On Friday, the agency’s independent adviser will discuss whether the evidence is strong enough to recommend the shot. With this advice, the FDA is expected to make a final decision within a few days.
The number of COVID-19 killed in the United States exceeded 500,000 this week, and vaccination has been slower than expected, hampered by logistical delays and weather delays. To date, approximately 44.5 million Americans have received at least one dose of vaccine from Pfizer or Moderna, and nearly 20 million of them have received the second dose required for full protection.
Tests showed that the Pfizer and Moderna vaccines were 95% effective in protecting against symptomatic COVID-19.
Dr. Paul Offit, a vaccine expert at the Children’s Hospital of Philadelphia, is part of the FDA’s advisory panel that will review J & J data on Friday and warns that none of the vaccines have been directly compared. Still, he was encouraged that a dose of the J&J vaccine works just as well to prevent serious illness as its two-dose competitors.
“This is a vaccine that prevents you from going to the hospital and dying at a level that is really comparable,” with the Pfizer and Modern vaccines, he said.
J&J tested its single option with 44,000 adults in the United States, Latin America and South Africa. Different mutated versions of the virus are circulating in different countries, and the FDA analysis warned that it is not clear how well the vaccine works against each variant. But J&J previously announced that the vaccine worked better in the United States – 72% effective against moderate to severe COVID-19, compared with 66% in Latin America and 57% in South Africa.
South Africa recently started giving the J&J vaccine to front-line health workers on a test basis after deciding that a vaccine from rival AstraZeneca had not shown strong enough study results against the particular variant that spreads there.
“I was reassured” that despite the fact that there were different variants, the J&J shot still protected against serious illness, says Dr. Jesse Goodman from Georgetown University, a former FDA vaccine chief. “It’s pretty robust data.”
If the vaccines eventually need to be updated, manufacturers are working to adapt their prescriptions. Moderna announced on Wednesday that it is ready to start testing experimental doses that better match the South African version of the virus.
In all countries, the analysis of the J&J vaccine showed that protection began to appear about 14 days after vaccination. However, 28 days after vaccination, there were no hospital stays or deaths in the vaccinated group, compared with 16 hospital stays and seven deaths in study recipients who received a dummy shot.
The FDA said efficiency and safety were consistent across racial groups, including black and Latino participants.
All the world’s COVID-19 vaccines have been tested differently, making comparisons almost impossible. It would not be surprising if one dose turned out to be a little weaker than two doses, and decision makers will decide if it is an acceptable trade-off to get more people vaccinated faster.
J&J has another large study underway to see if a second dose of its vaccine works better, which increases the prospect that countries could eventually add a booster kit if one proved to be justified.
Like other COVID-19 vaccines, the main side effects of J&J shots are injection site pain and flu-like fever, fatigue and headache. No participants in the study experienced the severe allergic reaction, called anaphylaxis, which is a rare risk for some other COVID-19 shots, even if they experienced a less severe reaction.
The FDA said there were no serious side effects associated with the vaccine so far, although further monitoring of blood clots was recommended. In the study, they were reported in approximately 15 vaccine recipients and 10 placebo recipients, which was not large enough to say whether the vaccine played a role.
J&J was on its way to becoming the world’s first single alternative until earlier this month. Mexico announced that it would use a single-dose version from China’s CanSino, which is made with similar technology to J & J’s shots but was originally developed as a two-alternative until a single-dose test began in the autumn.
The Pfizer and Moderna vaccines now used in the United States and many other countries must be kept frozen, while the J&J shot can last for three months in the refrigerator, making it easier to handle. AstraZeneca’s vaccine – largely in Europe and the UK – is manufactured in the same way and also requires cooling but takes two doses.
If the FDA clears the J&J shot for US use, it will not increase the vaccine supply significantly directly. Only a few million doses are expected to be ready for delivery in the first week. But J&J told Congress this week that they expected to give 20 million doses at the end of March and 100 million in the summer.
European regulators and the World Health Organization are also considering J & J’s vaccine. Globally, the company aims to produce approximately one billion doses by the end of the year.