What you need to know about mixing and matching COVID vaccines, getting boosters

Beginning Friday, COVID-19 booster shots for both Moderna and Johnson & Johnson are available to eligible populations. The CDC and FDA also authorized mixing and matching vaccines and boosters. Amna Nawaz discusses the latest with Dr. Leana Wen, an emergency physician and public health professor at George Washington University.

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  • Amna Nawaz:

    As we reported, beginning today, COVID-19 booster shots for both Moderna and Johnson & Johnson are now available to eligible populations. The CDC issued that guidance after an advisory committee unanimously approved it yesterday.

    The FDA also authorized mixing and matching vaccines and boosters.

    To help viewers understand more about what they should consider, I'm joined by Dr. Leana Wen, emergency physician, and public health professor at George Washington University.

    Dr. Wen, welcome back to the "NewsHour." Always good to have you here.

    Before we get to the booster news, I just want to ask you about something else related to young children and vaccines. We know Pfizer submitted data to the FDA showing its vaccine is highly, highly protective for children age 5 to 11.

    So, what does all this mean for potential FDA approval for children getting the vaccine that young?

  • Dr. Leana Wen, Emergency Room Physician:

    Well, the FDA is going to be reviewing all these data on Tuesday, when they meet, and then the CDC is going to be reviewing it the week after.

    Right now, the data are encouraging. They're showing that, in addition to the vaccines being safe so far in the 2000 or so 5-to-11-year-olds who are being studied, the vaccines also produce a strong antibody response.

    And now we have data coming out of Pfizer that show that the vaccines also appear to protect well against symptomatic disease, almost 91 percent against symptomatic disease. It's now going to be up to the FDA and CDC to weigh the risks and benefits and to also say, are they going to make as full-throated of a recommendation as they will for older individuals, as in, might they make a more limited recommendation, saying that only high-risk children get the vaccine?

    We don't know. We shall see when they review the data next week.

  • Amna Nawaz:

    Great. We will be following that next week, for sure.

    Meanwhile, let's go back to the boosters now. Americans now have three possibilities for vaccine boosters. And there's new information too about mixing and matching. Let's just walk through a few scenarios.

    If you got the Moderna or the Pfizer vaccine, meaning the dual mRNA doses, should you stick with the same brand for a booster if you get one?

  • Dr. Leana Wen:

    Most likely, yes.

    So, under almost all circumstances, we should say that the Pfizer and Moderna vaccines are generally interchangeable. There's no particular reason to switch from Pfizer or Moderna to one of the others. And, really, there are very few circumstances that they should be switching to a J&J vaccine.

    But let's say that you have a severe allergic reaction to Pfizer or Moderna. Or let's say that you also have had a prior case of myocarditis, inflammation of the heart muscle. In that case, you might consider switching to a Johnson & Johnson vaccine. But, otherwise, sticking to the same brand sounds just fine, as is if the only thing available in your area is Moderna, but you got Pfizer the first time, switching to the other mRNA vaccine is also OK too.

  • Amna Nawaz:

    What about the Johnson & Johnson vaccine, though, slightly different there, right? How should people who first got the single Johnson & Johnson vaccine look at boosters?

  • Dr. Leana Wen:

    Yes, so this is very different. And I should say that I am one of the 15 million Americans who got the one-dose Johnson & Johnson vaccine.

    For women under the age of 50, which is the category that I am in, I would not recommend that they get a second Johnson & Johnson booster. I would recommend that they receive one of the Pfizer or Moderna vaccines, one of the mRNA doses. And that's because the Johnson & Johnson vaccine has been associated with a very rare, but very serious blood-clotting disorder.

    This is not a run-of-the-mill blood clot. This is a very serious disorder that can be fatal, again, very rare. But for younger women, there is an option. There is another option of Pfizer or Moderna is not associated with this particular side effects. And so, for those individuals, I would definitely recommend a second mRNA dose, instead of the J&J booster.

    I should also mention that the FDA and CDC essentially are saying, even though they haven't explicitly said this, but they're essentially forecasting that the J&J vaccine should have been a two-dose vaccine from the start. And so, unlike Pfizer and Moderna, where only individuals in a high-risk category should be getting a booster six months after their first two doses, for the Johnson & Johnson vaccine, anyone after two months, regardless of risk, should actually be getting a second dose of something.

  • Amna Nawaz:

    So, there's a much broader category for people who got the Johnson & Johnson shot who should be getting a booster.

    You mentioned the timeline difference there. There's also a difference in guidance in terms of who should be getting a booster with the Moderna and Pfizer vaccines. Briefly, tell us who should be considering that right now.

  • Dr. Leana Wen:

    Two categories. There's one category who are recommended to get the booster and really should be getting a booster right now. Then there's a much broader group that's allowed to if they so choose to.

    The group that really should go right now and make an appointment, those are individuals who are 65 and older or 50 and older with a chronic medical condition who got the Pfizer or Moderna vaccine at least six months ago. They should really make an appointment in the next couple of weeks.

    Then there's a much broader category, anyone over the age of 18 who has occupational exposure or otherwise is high risk in a living situation. They can choose to go get a booster six months after their Pfizer or Moderna vaccine, in consultation with their physician, again, very different from Johnson & Johnson.

    Everyone who got the J&J vaccine, if they are more than two months out from their initial one-dose vaccine, really needs to get their second dose now. I have already gotten my booster dose.

  • Amna Nawaz:

    That's Dr. Leana Wen.

    It's complicated stuff. It's important stuff. We thank you so much for walking us through it, as people make plans maybe for the weekend ahead.

    Thank you very much for being with us.

  • Dr. Leana Wen:

    Thank you.

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