Q&A: Updated COVID-19 Vaccines For Fall 2024

KATHLEEN DAVIS: This is Science Friday. I’m Kathleen Davis. In the past couple of weeks, the latest versions of the COVID-19 vaccine have been approved from Moderna, Pfizer, and Novavax. It’s been almost four years since the release of the original mRNA vaccine. And since then there have been several rounds of boosters. It’s sometimes hard to keep up. Just 22% of eligible adults got the last round of updated vaccines and just 14% of children got theirs, according to the latest data from the CDC.

As we ride out the end of this crushing summer COVID wave, we thought that right about now might be a good time for a refresher on COVID vaccines. So we put out a call to our audience on social media and our newsletters to answer your most pressing questions about the latest COVID vaccines. Joining me to help answer those questions and more is my guest, Dr. Kizzmekia Corbett-Helaire, assistant professor of immunology and infectious diseases at Harvard’s T.H. Chan School of Public Health, based in Cambridge, Massachusetts. Thank you so much for being here today.

KIZZMEKIA CORBETT-HELAIRE: Thank you so much for having me.

KATHLEEN DAVIS: Well, we are very excited to have you here. So I think at this point it’s very possible that most people listening to this have gotten COVID at least once over the past few years. And some people might be listening and thinking COVID wasn’t so bad, why should I even bother with this new booster? What do you say to those people?

KIZZMEKIA CORBETT-HELAIRE: What I say to people is that there is always a chance that COVID-19 will cause more than the sniffles. There’s always a chance that you could end up in the emergency room. There’s always the chance that you would that you could end up hospitalized, especially for older people. And so what I say is that why even take that chance when you have the option to go to your local CVS and, in many cases, get a free vaccine that has been proven to decrease your chances of more severe disease. And so my hope is that what will happen is that as time progresses, people become more and more comfortable with the idea of getting seasonal vaccinations for COVID-19 along with flu.

KATHLEEN DAVIS: I want to ask you about the federal bridge program, which recently ended. And so that means that people without insurance can’t get this latest round of COVID vaccines for free. How significant is this change, in your opinion?

KIZZMEKIA CORBETT-HELAIRE: Well, so aside from standing on the mountaintops and shouting about vaccines, I am a proponent of health equity. And one of the parallels with inequities in health disparities, particularly with COVID-19 and other diseases, is that there are correlates with how much income people have and don’t necessarily have the means to spend $150 every season at CVS to get their vaccine. And so I think it is absolutely unfortunate that we’ve come to this point where we’ve almost dismissed what the outcomes of COVID could be and mean that from a governmental standpoint, from a regulatory standpoint.

Prior to the COVID-19 pandemic, seasonally flu would kill, what, 50,000 people in this country. And it was almost like, oh, OK, just dismiss it another flu season. And if we can prevent that– one death prevented is enough for me. And so hopefully we will try to– even if it’s not a full on bridge program, hopefully we will try to make vaccines more accessible for everyone forever.

KATHLEEN DAVIS: So if someone’s listening to this and they’re thinking I really got to get my butt into gear and get this booster, can you make this like a family affair? Can you get a child– your child in your life vaccinated at the local pharmacy with you?

KIZZMEKIA CORBETT-HELAIRE: Unfortunately, many pharmacies do not vaccinate children, particularly those under two years of age. And then even children under 12 in many pharmacies may have a hard time being vaccinated. So the best thing for you to do if you want to get your child vaccinated is to contact your pediatrician or contact your local publicly subsidized health department and they will point you in the right direction. I personally– I have, what is he now, 15-month-old– so one-year-old and he’s getting his booster on next Friday.

KATHLEEN DAVIS: I want to get to some questions from our listeners. Let’s play a voicemail that we received.

AUDIENCE: Hi, this is Alan from Boulder, Colorado. And my question is that I had COVID at the beginning of July, so about two months ago. And I was wondering when is the best time for me to get this new booster to best protect against the inevitable Thanksgiving and Christmas COVID surge?

KATHLEEN DAVIS: Yeah, great question.

KIZZMEKIA CORBETT-HELAIRE: So the CDC recommends that if you know that you have had a COVID infection in recent months to wait at least two to three months until getting your vaccine booster. So if he had a infection, I think he said in July, then that would be around October, which is perfect timing for him to be protected for the holidays.

And then the other question is for those who didn’t have a COVID infection in the last wave, if they want to be optimally protected for the holidays, when should they get their booster? So, first of all, I always like to warn people about restricting themselves on timing. So strictly understanding that Thanksgiving is only a hop, skip, and jump, maybe, what, two months away now?

KATHLEEN DAVIS: Mmm-hmm.

KIZZMEKIA CORBETT-HELAIRE: And so if you were to get boosted today, you would have a lot of antibodies waiting to protect you against the COVID-19 virus come Thanksgiving. But, optimally, about two to three weeks before for any major surge would be the best way to protect yourself.

KATHLEEN DAVIS: So what about for folks who are over 65?

KIZZMEKIA CORBETT-HELAIRE: Go today? I always like to tell people– for people who are over 65 or even for us who have older people in our lives who we love and hold dear to our hearts– grandmothers, aunts, and uncles– make it a date. My grandmother gets so excited for one of her 30 grandchildren to pick her up, get her vaccines, and go out to eat after. And so make it a date, spend time with your grandparent, and help them get vaccinated.

KATHLEEN DAVIS: So it’s been recommended that people over 65 can get a vaccine twice a year. Is that accurate?

KIZZMEKIA CORBETT-HELAIRE: Previously, it has been twice a year. But the one thing that is important is that the CDC and the FDA– they continuously review the epidemiology, so how the virus is transmitting, how well the vaccines are protecting, and they make continuous recommendations.

So to say that someone 65 or up may have to get a vaccine six months from now may not be necessarily true. I always remind people that right now we’re in this moment where we are following the COVID-19 waves and our regulatory agencies are making recommendations in real time based on real data. And so keep a watch out in six months, but worry about your vaccine and your booster for this fall right now.

KATHLEEN DAVIS: So we got a question from Michael. And it sounds like there might be some nuances here. And Michael wonders why everyone is not currently being advised to be on a twice a year schedule because we are currently seeing this summer and then later a winter wave. Is that something that has an easy answer?

KIZZMEKIA CORBETT-HELAIRE: That does have a fairly easy answer? So in the review of the data at the time of the beginning of that wave, around the time also– I believe it was the JN.1 variant started to circulate– in the review of that data, people under the age of 65 were still being very well-protected against severe disease and actually even some very mild disease at that time. And so there was no reason to ask for them to get boosters because their fall vaccine was doing just OK at protecting them against severe disease and mild disease.

KATHLEEN DAVIS: So a question that we’ve gotten a few times from listeners that is also a question that I have is that we’re hearing a lot about updated vaccines. Is that different from a booster? Is that the same as a booster?

KIZZMEKIA CORBETT-HELAIRE: That is a very good and nuanced question. So booster– think about that term as your everyday language when you’re talking to your friends and talking to me because I’m your friend too. And think about updated vaccine as the more official term and they are essentially interchangeable. I do want to remind people that to say that it is a booster means that you would have gotten COVID-19 vaccines previously. But if you have not, that does not mean that you cannot go and get your updated vaccines. So there is a little bit of nuance, but I would say that for most people you can use them interchangeably.

KATHLEEN DAVIS: Adjacent to that question, we got a question from Wanda from Canton, Michigan, and she asks, what are the pros and cons of available vaccine options? We’ve got the two mRNA vaccines– Moderna, Pfizer– and then we have protein-based Novavax. I’ve read about the benefits of mixing and matching vaccines. Is there any merit to that?

KIZZMEKIA CORBETT-HELAIRE: There have been a couple of studies that have looked at responses of mixing and matching various vaccines. I would say that, overarchingly, those studies are very what we would call nitpicky, meaning that they look at very specific antibody responses and they’re not necessarily gauging on a population level what protection looks like. And so any vaccine that is approved to be a booster– whether it be Novavax, Moderna, or Pfizer in this country– is a very, very good vaccine for you to get.

There are pros and cons when you think about– the protein vaccines have tended to have less reactogenicity that– what that means are basically those little mild side effects– the soreness in the arm, the redness in the arm, the fevers that you get after your vaccine– but other than that, any vaccine is a good one. People think of me as the Madonna girl because my team helped develop the Moderna vaccine and my last two boosters, this year and last year, were Pfizer.

KATHLEEN DAVIS: So you’re not loyal to the Moderna brand.

KIZZMEKIA CORBETT-HELAIRE: That was just what was available at CVS for me, so why not.

KATHLEEN DAVIS: Right. And so regarding Novavax, because it is a little bit different, would that potentially offer more protection if you’ve had Moderna or Pfizer shots before?

KIZZMEKIA CORBETT-HELAIRE: No.

KATHLEEN DAVIS: OK. So our next question is one that we do frequently get from listeners, and I think it’s as important as ever to clarify. Is it possible to overwhelm or confuse our immune system with too many vaccine doses? Can that be bad?

KIZZMEKIA CORBETT-HELAIRE: The way that I like to think about overwhelming my immune system is that for every single thing you come into contact with all day, every day, your immune system is learning about that thing, whether it be the bacteria on your desk or some virus that someone sneezed on you on your commute to work on the train. Your body is learning. So the immune system is great at not being overwhelmed.

There have been terms thrown around such as immune exhaustion. And that does happen, but, in this case, it’s not necessarily a thing because you aren’t getting vaccinated every day. You’re getting vaccinated six months to a year apart, depending on your age. And that’s enough time to let your immune cells settle down and allow yourself to be boosted again. So overwhelm is not necessarily something we should really think about in this case.

As far as confusion, in science, we call that immune imprinting or even more technically original antigenic sin. But I love that someone called it confusion. I’m going to start using that, which basically means that you start to teach your immune system about the virus so much that it’s like I don’t want to learn anymore. I’m just going to go back and start doing the thing I did when I got my original vaccine, making a lot of antibodies towards the original strain.

And, sure, I’ll still protect, but maybe I’m not making as many antibodies to the vaccine that I just saw. So you still get boosted, but there is some phenomenon towards your body leaning towards wanting to continue to protect you against the older viruses. Still boosted, still protected, but inside of your body, your cells are like, ehh, I like the old virus better, let me go make more antibodies to that.

KATHLEEN DAVIS: So a question we got from Wendy from Sonoma, California is are the OTC rapid COVID tests still accurate given the number of variants?

KIZZMEKIA CORBETT-HELAIRE: Yes. I also want to remind people that COVID tests are also regulated heavily continuously. So if they were not accurate, they would not be on your shelves.

KATHLEEN DAVIS: I have a personal question. So I have Covid tests in my bathroom that are probably about two years old now. Do those still work? I mean, should I throw them out?

KIZZMEKIA CORBETT-HELAIRE: They probably are expired. The longest that I’ve seen one is a year. So I would check the expiration date. And, for sure, if one is expired, do not use it.

KATHLEEN DAVIS: So every time we talk about vaccines on the show, there are always some people who are worried about side effects or potential harms that getting COVID vaccines may cause. How can people weigh potential side effects versus the benefits of getting the booster?

KIZZMEKIA CORBETT-HELAIRE: So this is absolutely something that we all need to heed, especially– when I say we, I’m talking about scientists, health care practitioners, and doctors– and that people really do have this real fear. And to be frank, there are anecdotal, small amounts of rare cases where people have contributed a long-term effect, which is a vaccine injury, to the COVID-19. Oftentimes it’s something like tingling in your extremities or people have even said that they like are really tired all the time following getting a COVID-19 vaccine. But the cases are very rare and there have been no correlation with any long-term side effects on– at mass at all.

For the long-term side effects that have been correlated, there have been instances of a particular side effect in young boys when getting the vaccine, but that’s just about it. Overarchingly, these vaccines continue to save lives, have saved millions of lives, and they continue to keep people from getting really severely ill with COVID-19 infection.

The one thing that I just want to end with the vaccine injury note is that do not be ashamed that you feel that fear. I find when I come in contact with people, especially because of like who I am, they don’t feel like they can say that they’re afraid of the vaccine because of something that they heard that did that it did to someone somewhere. I think that is a real concern, especially because we are asking of you to get vaccinated, at this point, every year. And so just lean into that fear in a way that allows you to gather information, asking questions of people that– from trusted sources, asking your doctor, and asking your friends about their experiences with the vaccines as well.

KATHLEEN DAVIS: Well, that’s a great note to end on. Thank you so much. Dr. Kizzmekia Corbett-Helaire, assistant professor of immunology and infectious diseases at Harvard’s T.H. Chan School of Public Health based in Cambridge, Massachusetts. Really appreciate your time here today.

KIZZMEKIA CORBETT-HELAIRE: Thank you. Now go throw away those old tests.

KATHLEEN DAVIS: All right. I will. And I’ll always think of you when I look at those expiration dates.

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