WASHINGTON (CN) — New findings on Moderna’s Covid-19 vaccine released Tuesday confirm its high efficacy rate and could lead to imminent approval for emergency use.
Moderna’s vaccine is 94.1% effective against the novel coronavirus and in most cases side effects have mainly involved things like fever and headache or tenderness at the injection site, according to a Food and Drug Administration briefing document.
The agency is expected to authorize the vaccine for emergency use as soon as Friday, which means Americans could have access to a second vaccine as early as Monday after injections of Pfizer’s vaccine began this week.
Last week, the FDA approved Pfizer’s and BioNTech’s jointly produced vaccine for emergency use and the first doses were administered to health care workers just 24 hours ago. That vaccine’s efficacy rate is 95%.
During a committee meeting on Thursday, the FDA will weigh concerns over the Moderna vaccine from both scientists and the public. If it’s approved, about 6 million doses could be distributed next week.
Tuesday’s FDA report warns a handful of trial participants developed symptoms like Bell’s palsy. According to the Mayo Clinic, Bell’s palsy is an acute weakness in facial muscles that can cause half or part of a person’s face to droop. It is typically a temporary condition and resolves on its own or with the aid of physical therapy. It can occur after a person has contracted a viral infection.
Of Moderna’s 30,000 clinical trial participants for its Covid-19 vaccine, just three people who received it developed Bell’s palsy symptoms, according to the FDA report.
Trials for Pfizer’s vaccine, which involved about 43,000 test subjects, found similar symptoms in four people. Both Moderna and Pfizer confirmed each person who developed the disorder received the vaccine, not a placebo.
At least two of the Moderna vaccine recipients, both women, saw their symptoms resolved. One woman that developed the facial freezing was 67 years old with diabetes and had been hospitalized for a stroke 32 days after taking the vaccine. Another woman, who was 30 years old, developed Bell’s palsy 28 days after the vaccination.
“An additional case of Bell’s palsy in the vaccine group was reported with the primary analysis safety data…and occurred 22 days after vaccination in a 72-year-old female; this event was still ongoing at the time of safety report,” the report states.
The FDA stopped short in the 54-page report of calling these symptoms a “side effect” from the new vaccine but emphasized that the incidents warrant close surveillance.
“Currently available information is insufficient to determine a causal relationship with the vaccine,” the report states.
In an interview for the Journal of the American Medical Association released Monday, Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said he believes the Bell’s palsy symptoms were likely not a result of the vaccine. He said it’s more likely that the symptoms were just a rare but unfortunate occurrence.
In the United Kingdom, two people who took the Pfizer vaccine during a rollout there on Dec. 8 reported experiencing a major allergic reaction known as anaphylaxis. Officials in the U.K. have warned that people with a history of anaphylaxis should not take the vaccine.
The U.S. Centers for Disease Control and Prevention, however, has so far said the Pfizer vaccine is safe for people with a history of severe allergies. The agency recommends people with significant allergies remain under close review for about 30 minutes after receiving a dose.
“Unless you had an allergy that was a severe or allergic reaction to a vaccine, we’re not concerned about people going to get vaccinated,” Marks said on Monday.
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