FDA Confirms Johnson & Johnson Covid-19 Vaccine Works With 1 Dose

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Johnson & Johnson has developed a one-dose vaccine capable of preventing Covid-19, the Food & Drug Administration said Wednesday.

The assessment was made as part of the agency’s process for approving the vaccine. A final meeting is scheduled for Friday, after which the agency will decide whether to approve the vaccine for distribution. Researchers said vaccine was 66 percent effective in protecting against moderate to severe cases of the virus.

That percentage is significantly less than the efficacy rate for two earlier vaccines developed by Pfizer and Moderna and approved for use in December. The rate for those vaccines, which both require two doses to reach full efficacy, clocked in at about 95 percent and 94 percent, respectively.

However, unlike its competitors, Johnson & Johnson said it conducted testing to account for new variants of the virus, including variants stemming from Brazil and South Africa. Participants in trials for the vaccine included 44,000 people from the United States, as well as South America and South Africa. The company said the trials indicated the vaccine was 72 percent effective in the United States, 66 percent in South America, and 57 percent in South Africa.

The vaccine has also been the most effective tested to date in South Africa. A vaccine developed by Novavax, another U.S. company, had an efficacy rate in the region of 49 percent. And this month, the country halted trials of a vaccine developed by AstraZeneca-Oxford after determining it was mostly ineffective.