When a 2nd COVID-19 vaccine arrives, will it matter which one you get?

Kate Murphy
·Producer
Updated ·3 min read

The day after Americans began receiving their first doses of a coronavirus vaccine made by Pfizer, Food and Drug Administration staff endorsed the emergency use of a different vaccine, made by Moderna, which it called “highly effective.” Formal authorization by the FDA could come as early as Friday.

Which raises the question: Will Americans have a choice of which one to take? And if so, which should they choose?

The short answer is, this is no time to be choosy.

New data shows that the Moderna vaccine can begin to prevent asymptomatic infections after one of two doses, which could help slow the spread of the coronavirus. In its review, the FDA also confirmed Moderna’s previously stated vaccine efficacy rate of 94.1 percent after two doses, which is about the same efficacy level as the Pfizer vaccine. Yahoo News Medical Contributor Dr. Kavita Patel said, “Both the Pfizer and Moderna vaccines demonstrate some immunity starting after the first shot, but both shots are required to achieve the high rates of efficacy. Both vaccines also exhibit similar side effects, mostly localized soreness, but no serious adverse events were noted.”

Robert Luckey, COVID ICU Nurse, receives the hospital's first dose of the Pfizer-BioNTech vaccine for COVID-19 at Memorial Hermann Hospital in the Texas Medical Center Tuesday, Dec. 15, 2020 in Houston. Front line workers at Memorial Hermann were some of the first to receive the recently approved vaccine. The Pfizer vaccine was almost 95 percent effective at preventing patients from contracting COVID-19 and caused no major side effects in a trial of nearly 44,000 people. (Brett Coomer/Houston Chronicle via AP)

The FDA’s Vaccines and Related Biological Products Advisory Committee, a group of independent medical experts, is scheduled to review Moderna’s request for emergency use authorization for its vaccine on Thursday. If it is green-lit, Operation Warp Speed COO Gen. Gustave Perna told reporters on Monday, nearly 6 million doses of Moderna’s vaccine will be shipped to 3,285 locations across the country.

Pfizer’s vaccine was given emergency use authorization last week, and U.S. health care workers started to receive it on Monday. The hopeful news comes at a time of record-breaking COVID-19 cases overwhelming hospitals and as the U.S. witnessed a grim milestone of 300,000 virus deaths on Monday.

“The two vaccines are not interchangeable because of the dosing in the vials,” Patel said, “but they offer similar efficacy and have very similar profiles, which is reassuring for such a novel vaccine technology.” And when it comes to being able to choose between vaccines, she says, “it’s highly unlikely that you’ll have the luxury of making choices, because you can imagine that if there is a vaccine with this high of a rate of promise, everybody is going to want one.”

Who can get a COVID-19 vaccine and when?

Patel says frontline health care workers and potentially vulnerable elderly in settings like nursing homes are the first in line. Young, healthy adults probably won’t get vaccinated until late summer to fall of 2021. “Getting the vaccine into the broader population will require consistent messaging as well as an ongoing dialogue about what we do and don’t know. There are populations that were not significantly represented such as pregnant/lactating women and people with compromised immune systems,” she said.