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Moderna says its COVID-19 vaccine is 94.5 percent effective in early analysis

Moderna says its COVID-19 vaccine is 94.5 percent effective in early analysis


The company announced preliminary results on Monday

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Photo Illustration by Rafael Henrique/SOPA Images/LightRocket via Getty Images

Moderna’s COVID-19 vaccine candidate is 94.5 percent effective, according to early data released by the company in a press release. That’s slightly higher than the efficacy reported by Pfizer and BioNTech; they announced a 90 percent efficacy for their vaccine candidate last week. Both Moderna and Pfizer said they plan to ask the Food and Drug Administration for authorization within a few weeks.

The data still hasn’t been published or reviewed by outside experts. These efficacy readings are higher than many experts were expecting, though. The FDA said it’s looking for vaccines that were at least 50 percent effective.

“Aspirationally, you would like to see 90, 95 percent, but I wasn’t expecting it. I thought we’d be good, but 94.5 percent is very impressive,” Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told The New York Times.

In this initial evaluation, Moderna said that there were 90 cases of COVID-19 in the clinical trial group that received the placebo and only five cases in the group that were given a vaccine. The company also checked to see how many of the cases were severe, and it found 11 severe cases in the placebo group but none in the group receiving the vaccine.

There were no serious safety concerns with the vaccine

There were no serious safety concerns with the vaccine, but participants reported some side effects like fatigue, headache, or pain at the injection site. They generally passed quickly.

Moderna had the first vaccine to enter clinical trials in March. Only 63 days after the genetic sequence of the virus was posted online, the company injected the first volunteer with its vaccine candidate. It was able to move so quickly because it used a gene-based technology to create its vaccine. Those types of vaccines are relatively simple to create once researchers know the viral gene they’re trying to target.

Pfizer and BioNTech’s vaccine was built using the same method. The two are made from tiny pieces of mRNA, which gives the human body instructions to produce copies of the coronavirus spike protein. Then, the immune system learns to defend against that protein. Gene-based vaccines are the long-promised future of vaccine development, but they’ve never been approved for use in people by the FDA. The early successes of the Moderna and Pfizer vaccines are a promising sign for the method.

Moderna also announced today that its COVID-19 vaccine can be stored at refrigerator temperatures (between 36 and 46 degrees Fahrenheit, or 2 to 8 degrees Celsius) for up to 30 days, which should help make storage and distribution of this vaccine easier. One worry with gene-based vaccines is that they are extremely fragile and have to be stored at ultracold temperatures. Pfizer and BioNTech’s vaccine has to stay at -70 degrees Celsius (-94 degrees Fahrenheit), giving Moderna a slight logistical edge.

Previously, Moderna thought its vaccine could only stay in a refrigerator for seven days. The longer window “would enable simpler distribution and more flexibility to facilitate wider-scale vaccination in the United States and other parts of the world,” Juan Andres, chief technical operations and quality officer at Moderna, said in a press release.

Moderna said it would have 20 million doses of its two-shot vaccine available by the end of 2020 and 500 million to 1 billion doses in 2021. The United States government has a deal with the company for 100 million doses of its vaccine through “Operation Warp Speed,” a federal program aimed at accelerating COVID-19 vaccine development. That’s in addition to the 600 million doses of the Pfizer vaccine purchased by the US, 50 million doses of which could be available this year. That vaccine also takes two shots.

Meanwhile, the US is seeing record numbers of COVID-19 cases each day, with no end in sight. Even with this promising data, a vaccine won’t be available to most people for a few months at the very least. That makes protective measures like wearing masks and avoiding gatherings all the more important as the vaccines move into the authorization process. The more people who make it through the next few weeks of the pandemic, the more who could benefit from these vaccines.

Correction November 16th, 8:50AM ET: An earlier version of this article reversed the number of cases found in the placebo and vaccine groups. We regret the error.