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  • The United States now has authorized the use of two coronavirus vaccines to help control the pandemic.
  • The FDA issued an emergency use authorization (EUA) on Dec. 18 for a coronavirus vaccine developed by Moderna.
  • The first doses of Moderna’s vaccine are expected to be given early next week.

All data and statistics are based on publicly available data at the time of publication. Some information may be out of date.

The Food and Drug Administration (FDA) issued an emergency use authorization (EUA) Friday, Dec. 18, for Moderna’s coronavirus vaccine for use in people 18 years and older.

Moderna developed the vaccine in collaboration with the National Institute of Allergy and Infectious Diseases.

The FDA’s approval comes as COVID-19 cases, hospitalizations, and deaths across the country continue to grow.

On Thursday, more than 114,000 people in the United States were currently hospitalized with the disease, and 3,438 people died of COVID-19, according to the COVID Tracking Project.

The Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention (CDC) will vote Saturday on whether to recommend that the vaccine be deployed for use.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told the “Today” show on Friday that he anticipates the first doses of Moderna’s vaccine will be given early next week.

On Thursday, the FDA’s Vaccines and Related Biological Products Advisory Committee voted 20-to-0 in favor of the EUA, with 1 member abstaining.

The vote came after the panel of independent scientific experts, infectious disease doctors, and statisticians spent much of the day reviewing data from Moderna’s phase 3 clinical trial.

“Overall, the data show that the vaccine is extremely effective — 94.1 percent — at preventing symptomatic COVID-19 cases and 100 percent effective at preventing severe COVID-19 cases,” said Dr. Shobha Swaminathan, an associate professor and infectious disease physician at Rutgers New Jersey Medical School.

Swaminathan, who was not part of the advisory panel, is principal investigator for the Moderna vaccine trial at Rutgers.

In addition, “the efficacy observed is broadly consistent across all evaluated subgroups,” Dr. Tal Zaks, chief medical officer of Moderna, told the advisory panel on Thursday. “A reduction in total symptomatic cases predicts a reduction in cases leading to hospitalization, intensive care, and death.”

The United States now has two approved coronavirus vaccines — both will be needed to help contain the pandemic.

The FDA issued an EUA for the Pfizer-BioNTech vaccine last week for use in people 16 years and older. This vaccine has an effectiveness of 95 percent.

Healthcare workers across the United States received the first doses of this vaccine on Monday.

EUA is short of full FDA approval. Moderna will continue to study the safety and effectiveness of its vaccine until it has enough data to request full approval.

U.S. officials said they plan to ship just under 6 million doses of Moderna’s vaccine to the states as soon as the FDA issues the EUA.

The federal government has preordered 200 millions doses of Moderna’s vaccine, enough to vaccinate 100 million people. (The vaccine requires 2 doses per person.)

Both Pfizer’s and Moderna’s vaccines need to be stored in a freezer until ready for use. But Moderna’s vaccine can be kept in a standard freezer, while the Pfizer-BioNTech vaccine needs to be kept in extremely low temperatures: between -112°F and -76°F.

Moderna’s vaccine also has a shelf life at standard refrigeration of 30 days.

This will make Moderna’s vaccine easier to distribute, especially in areas that don’t have access to specialized ultralow-temperature freezers.

The FDA’s scientific reviewers said that Moderna’s 2-dose vaccine was “highly effective” in preventing PCR test-confirmed COVID-19 from occurring at least 14 days after people received the second dose, according to the FDA’s briefing document for Thursday’s meeting.

The analysis also found that the vaccine had a “favorable safety profile, with no specific safety concerns identified that would preclude issuance of an EUA.”

While the overall efficacy was 94.1 percent, the vaccine’s effectiveness was lower in older people, the FDA analysis found. In people 65 years and older, the efficacy was 86.4 percent, compared to 95.6 percent in younger adults.

However, “the number of cases is too small in [the older adults group] to make meaningful conclusions,” Swaminathan said, but “it is still much higher than most other FDA-approved vaccinations.”

Efficacy is a measure of how well a vaccine works during a clinical trial. Real world effectiveness may be lower due to a number of factors.

Moderna plans to do a follow-up study at Kaiser Permanente Southern California to determine the vaccine’s effectiveness. This study will run through the end of 2023.

The data also suggests that a single dose of the vaccine may provide some protection, although the efficacy was 50.8 percent, according to an earlier analysis.

It’s not clear how long the protection offered by 1 dose would last, though, because most people received their second dose after 28 days.

Moderna’s data also suggests that the vaccine can prevent severe disease. Of the 30 participants who developed severe illness, all had received the inactive placebo, not the vaccine.

The most common adverse effects in people who received the vaccine were:

  • pain at the injection site
  • fatigue
  • headache
  • muscle pain
  • joint pain
  • chills

These effects lasted for 2 days on average.

These types of reactions are common with vaccination, and are generally due to the immune response generated by a vaccine.

However, given the duration of the side effects, people may need to schedule their vaccination so they can rest the next day.

There were three reports of Bell’s palsy, a temporary weakness in muscles in the face, in people who received the Moderna vaccine. There was also one case in the placebo group.

Three of these cases had resolved on their own by the time Moderna submitted its report to the FDA. The last was still improving.

The FDA scientists wrote that there currently isn’t enough information to link these cases to the vaccine, but recommended ongoing monitoring for Bell’s palsy in people who have been vaccinated.

There were also signs of possible mild allergic reactions to the vaccine, although people who received the placebo showed similar symptoms, but at a slightly lower rate.

Two U.K. healthcare workers had a severe allergic reaction, or anaphylaxis, last week after receiving the Pfizer-BioNTech vaccine. They recovered after treatment.

Both U.K. healthcare workers had a history of allergies to medications and carried an epinephrine autoinjector, the New York Times reported.

Two healthcare workers in Alaska also had a severe allergic reaction on Tuesday after receiving the Pfizer-BioNTech vaccine, according to the Times. One of the workers didn’t have a history of allergies.

The issue of anaphylaxis came up early during the FDA advisory panel’s review of the Moderna data on Thursday.

“While the totality of data at this time continues to support vaccinations under the Pfizer EUA without new restrictions, these cases underscore the need to remain vigilant during the early phase of the vaccination campaign,” Doran Fink, deputy director of the FDA’s division of vaccines and related products applications, told the panel.

The U.K. regulatory agency recommends that people who have a “history of anaphylaxis to a vaccine, medicine or food” don’t receive the Pfizer-BioNTech vaccine.

However, the FDA has taken a less strict position. In its EUA for the Pfizer-BioNTech vaccine, it recommends that anyone with a history of a “severe allergic reaction” to any components of the vaccine to not get the vaccination right now.

The FDA adds that appropriate medical treatment should be “immediately available” at vaccination sites in case someone receiving the vaccine has an allergic reaction.

The high efficacy of Moderna’s vaccine is welcome news as the pandemic continues to rage in the United States.

The country hit a grim milestone of 300,000 deaths earlier in the week, and gatherings and travel over the upcoming holiday season threaten to worsen that toll.

However, several questions about the vaccine remain unanswered, with additional studies needed to fill in these gaps.

“We still need information on vaccine safety and efficacy in sub-populations such as pregnant women, children and adolescents, and persons with immunosuppressed conditions,” Swaminathan said.

The FDA briefing said that Moderna has submitted data from a developmental and reproductive toxicity study done in rats, with no adverse effects found. This type of study is needed before the vaccine can be tested in clinical trials in pregnant women.

Moderna also plans to start a clinical trial of its vaccine involving children ages 12 to 17, The New York Times reported.

Other unknowns include whether the vaccine can prevent asymptomatic infections or keep people from transmitting the virus to others.

Because of this, people who have been vaccinated will need to continue to wear masks, practice physical distancing, and take other measures to protect those most at risk.