Moderna's Vaccine May Have Key Edge Over Pfizer's

Monday morning brought more hopeful news about a coronavirus vaccine, this time from Moderna. The company announced that its candidate, still in late-stage trials, appears to be 94.5% effective. That's even better than the 90% rate reported by Pfizer last week. Related coverage:

• First doses: Moderna is on track to win FDA approval and have 20 million doses ready for Americans by year's end, reports the Wall Street Journal. This is a two-dose vaccine, meaning that's enough for 10 million people. Pfizer (also a two-dose vaccine) has previously said it expected to have 50 million doses by year's end, per the New York Times. The federal government will help determine who gets the first shots, but front-line health workers and first responders are expected to be among them.

• Longer term: Moderna has pledged to make up to 1 billion doses in the next year, while Pfizer plans to make another 1.3 billion, reports USA Today. Several other companies in the US and around the world also are working on vaccines, but the timetable of when shots will be available to the majority of Americans remains unclear.
• A benefit: Moderna researchers say its vaccine has a longer shelf life than anticipated. It will last 30 days (up from seven) in a standard refrigerator and 12 hours at room temperature. "This vaccine presents the opportunity of using doctors' offices, clinics, and pharmacies as vaccination sites," a Vanderbilt infectious disease expert tells the Times. That could give it an edge over Pfizer's vaccine, which requires colder temperatures. Moderna's vaccine can be stored up to 6 months at minus-4 degrees, while Pfizer's must be stored at minus-94 degrees, per CNBC.
• Questions: It's not surprising that both vaccines are similarly effective because both use "mRNA" technology, per STAT News. (Other candidates in the pipeline use a different technique.) The site rounds up lingering unknowns, including whether the shots will be long-lasting or require boosters; more data also is needed on side effects, including fatigue, muscle pain, and headaches. However, results so far are encouraging on that front, with most issues clearing up in a day or two.
• Big picture: "It’s extremely good news," Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, tells the Washington Post in the wake of the Moderna news. His institute helped the company develop the vaccine. "I describe myself as a realist, but I’m fundamentally a cautious optimist. I felt we’d likely get something less than this," Fauci says. "I said certainly a 90-plus-percent effective vaccine is possible, but I wasn’t counting on it."

(More coronavirus vaccine stories.)