"From a consumer standpoint, you take whichever one you can get," said Dr. Thomas Giordano. "There's not much to favor one over the other at all. Both look great."
Dr. Giordano is chief of Infectious Diseases at Baylor College of Medicine. He says the safety and efficacy date shows both vaccines appear to be nearly 95% effective.
Both use very similar mRNA technology.
If you get the Moderna vaccine, you'll get two 100-microgram doses 28 days apart. If it's Pfizer, you'll get two 30 microgram doses 21 days apart.
"There's no mix and matching," said Giordano. "If you get one, the second dose has to be the same manufacturer, the same exact vaccine. My recommendation is as soon as you get the first dose don't walk out wherever you are without an appointment for the second dose."
Moderna's vaccine could be used in people 18 and older. Pfizer's is open to those just slightly younger, those 16 and older.
The major difference between the two is how they need to be stored and handled. Pfizer's vaccine must be stored at ultra cold -100 degree Fahrenheit temperatures and can only be refrigerated for up to five days before it expires.
Moderna's vaccine can be kept at just -4 degrees Fahrenheit. That's the average temperature of a home freezer, and it can be refrigerated for a month before it goes bad.
That means major hospitals could rely more on the Pfizer vaccine, while smaller practices, pharmacies, and facilities will more easily handle Moderna's product.
"The Moderna one is more forgiving and easier to deal with," said Giordano.
Moderna's vaccine won't be the last. There's more vaccines in the production pipeline. And experts say the more options out there, the faster this pandemic will be over.
"There's already pent up demand that we can't meet, so we're looking forward to the next shipment next week," said Giordano. "Having another vaccine can only help."