FDA Authorizes Moderna COVID-19 Vaccine

On December 17, the Food and Drug Administration (FDA) issued Emergency Use Authorization (EUA) for the second COVID-19 vaccine, greenlighting a vaccine made by Moderna Therapeutics.

“With the availability of two vaccines now for the prevention of COVID-19, the FDA has taken another crucial step in the fight against this global pandemic that is causing vast numbers of hospitalizations and deaths in the United States each day,” FDA Commissioner Stephen M. Hahn, MD, said in a statement.

An advisory panel to the FDA voted Thursday to recommend that Moderna’s vaccine be authorized. The panel, called the Vaccines and Related Biological Products Advisory Committee (VRBPAC), voted 20 in favor of the recommendation, with one abstention.

EUAs are permitted in the U.S. for drugs, devices, and vaccines if the benefits outweigh the risks, which is the question the committee voted on. EUAs allow shorter time periods for clinical trials so that the device, drug, or vaccine can be made available more quickly. Both Moderna and Pfizer—which was granted an EUA for its COVID-19 vaccine last week—are expected to continue their clinical trials and ultimately file for full approval.

In light of this authorization, vials of the vaccine can be shipped throughout the U.S. to be used in an initial phase for healthcare workers as well as residents and staff of long-term care facilities. 

During discussions before and after Thursday’s vote, members of the panel, made up of physicians, researchers, biostatisticians, and consumer representatives were largely enthusiastic about the Moderna vaccine. “The answer to the question [of whether to recommend the EUA] is clearly yes,” Paul Offit, MD, director of the Vaccine Education Center at Children’s Hospital of Philadelphia, said during the committee hearing, which was publicly available to stream.

Data from Moderna that was reviewed by the FDA and presented today show the vaccine to be about 95% effective, the same effectiveness rate as the Pfizer vaccine. Significantly, that rate of effectiveness was seen in all races and ages, according to Rachel Zhang, MD, an FDA medical officer who presented data about the vaccine to the committee.

Moderna’s vaccine is being recommended for people ages 18 and older, while the Pfizer vaccine is authorized for use in people ages 16 and older.

The Pfizer and Moderna vaccines are similar but not identical. Both are based on a platform called messenger RNA, which uses genetic material to prompt the body to make antibodies to SARS-CoV-2, the virus that causes COVID-19. The genetic material is encased in a bubble of fat, and the components of the bubble are slightly different for each of the vaccines. 

There’s a major difference in how the vaccines must be stored. The Pfizer vaccine needs to be stored at about -70 °C, which is about 50 degrees colder than any other vaccine used in the U.S. This requires specialized freezers. Moderna’s vaccine is stored at about -20 °C—about the same temperature as a home freezer—and is more suitable for local pharmacies.

Safety Discussions

Because at least four people—two in the U.K. and two in Alaska—suffered severe allergic reactions to the Pfizer vaccine, the panel discussed the topic of allergic reactions at length. Neither Pfizer nor Moderna reported severe allergic reactions during their clinical trials, which together encompass about 80,000 people. But some effects of vaccines “sometimes only emerge after use in millions of people,” LJ Tan, MS, PhD, chief strategy officer for the Immunization Action Council, a group that advocates for wider vaccine use, tells Verywell. 

Doran Fink, MD, Deputy Director-Clinical in the Division of Vaccines and Related Products at the FDA, told the committee that the fact that the agency knows about the reactions is an indication that “the system works,” and that FDA surveillance is continuing. 

As with the Pfizer vaccine, Moderna’s side effects included fever, chills, fatigue, headache, muscle, and joint pain, and were more common after the second dose.

Both the Moderna and Pfizer-BioNTech studies reported a small number of cases of a temporary facial paralysis called Bell’s palsy and both companies are looking out for more reports of the condition. 

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.