Differences between Pfizer and Moderna vaccines

HOUSTON – Earlier this week we watched as the Pfizer vaccinations began locally and nationally and the FDA said both vaccines are almost equal at being effective.

Here’s how they’re similar:

They both need two doses.

Pfizer administered 21 days apart, Moderna will be 28 days.

You cannot get the first dose of one and the second of another. You have to receive the same drug and the CDC is helping to make sure everyone keeps track of when you get what with a small card you can carry for your records.

Asymptomatic efficacy still to be determined:

“The vaccine prevents disease at 95% rate but it prevents getting the coronavirus without disease, about 50% of the time,” Dr. Thomas Giordano from Baylor College of Medicine explained when asked about Pfizer. “It’s a lot better than 0% of the time, which is what it is if you have no vaccine. But that’s one of the reasons actually why we recommend that even after vaccination we still need to wear a mask because you could still get infected with coronavirus, not know it, you’re more likely to be asymptomatic not get sick, but still give it to someone else.”

The two vaccines are very similar, but, according to the U.S. Health and Human Services Secretary, Alex Azar, there are a few key differences that make Moderna’s vaccine “more flexible.”

Here are the key differences:

We know Pfizer had to be kept at temperatures close to -100 degrees, requiring expensive freezers and lots of dry ice.

Moderna’s vaccine does not need that. Actually, it can basically stay effective at the same temps as your home freezer.

Pfizer can only thaw to refrigerated temps for five days before it expires.

Moderna can be at refrigerated temps for 30 days before expiring.

Meaning, Pfizer’s is a good option for major institutions like TMC hospitals. Moderna might be the preferred option for clinics and pharmacies.

However, Kroger said their pharmacies are actually planning to get the Pfizer vaccine next week.

“They’re over 900 vaccines per case, they can stay in that case for over two weeks. The bottom line is we’ll be using them right away but additionally, we have third-party partners where we can store the vaccine if we need to do so but I don’t think the goal is to store the vaccine, I think the goal is to get the vaccines to our stores, have the pharmacists deployed and administering these vaccines,” Joe Kelley, president of Kroger, explained.

Kelley said they’re working through the tiers just as the CDC has instructed (frontline workers, nursing homes, etc.) but they think they can move to their own employees (who fall under essential workers) by early next month.