Next Up in Line for COVID Vaccines: Kids

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The COVID-19 vaccine rollout has now expanded to include young adolescents among those eligible to receive Pfizer’s two-dose shot. This expanded authorization comes as mask mandates across the country are lifting.

Adding younger teens means an additional 17-million sleeves can be rolled up to receive a shot as the U.S. pushes forward with the largest mass vaccination program in history. But, even if vaccinations mean life can go ‘back to normal,’ many parents are concerned over potential side effects and long-term impacts of the vaccine. Others, however, are rushing to vaccinate ahead of summer camps. Every parent wonders: when will a vaccine be available for even younger kids? Some parents have even considered enrolling their young children in clinical trials for an earlier shot at a dose.

Joining us this week is Paul A. Offit, MD, director of the Vaccine Education Center and professor of pediatrics in the Division of Infectious Diseases at Children’s Hospital of Philadelphia. He’s also a member of the FDA’s Vaccines and Related Biological Products Advisory Committee (VRBPAC), the impartial group of experts that has been responsible for giving the greenlight for emergency use authorization.

The following is a transcript of his interview with “Track the Vax” host Serena Marshall:

Marshall: Dr. Offit, thanks for joining us here at Track the Vax. We’re now tracking these vaccines into young teenagers.

Offit: All good news.

Marshall: Is that a timeline that you thought looking back maybe, you know, 6 months ago we would be at right now?

Offit: I don’t think any of this is a timeline I thought we would be at. I mean, when we isolated that virus in January of 2020 and the sequence of the SARS-CoV-2 virus was published. I don’t think there’s a scientist on this planet that would have thought that within 11 months we would have two large, prospective placebo-controlled clinical trials showing that this vaccine or these vaccines were remarkably effective.

And now that they’ve been in, you know, more than 150 million people in the U.S. alone, remarkably safe. I don’t think anybody would have predicted any of this, but I’m also happy that, you know, within really just a few months of those original submissions in December that we now have excellent data in children 12 to 15 years of age.

It’s all amazing.

Marshall: Let’s dive into that data a little bit now that it has been authorized for children 12 and up. That phase III clinical trial — only about 2,200 people. That seems really small.

Offit: Right. But they did have 18 cases of disease. So you had roughly 2,300 children that were divided in half. Half received the vaccine, half placebo. There were 18 cases of infection and disease — all in the placebo group. I mean that’s a clear statistically significant difference. Also, the immune response or so-called geometric mean titers of virus specific neutralizing antibodies was extremely high.

I mean, it was excellent. Frankly, as good if not better than those that were in, say, 17- to 25-year-olds. And it was safe. And so, you can do a bigger trial. You could say, instead of doing 2,300 children, you can do 23,000 children. And so instead of 18 children having to suffer, you know, infection and disease, it could be 180 children. But do you really want that?

I mean, the question is never when do you know everything? It’s when do you know enough. I think at this point you know enough because you have a lot of experience with this vaccine now in people roughly a similar age, 16- to 25-year-olds. So I think you can, you’re jumping with a net here.

Marshall: You just explained the titers and how it was lower in infection in the younger age group. Was that expected since as you get younger, we seem to see less infection?

Offit: Well, as a general rule, younger people have had healthier, more robust immune responses. So it’s not surprising at all that they would have excellent, high-titered immune responses. And also the infection, while it is true that the children generally are infected less frequently and less severely.

When the virus first came into the U.S. the children accounted for about 2.4% of the total infections. Now they account for about 24% of the infections, which I think is a lot of different things. I think one is we’re more attentive to that. I think children are more likely to be tested now and we’re protecting older people.

So you’re seeing … now that we’ve left them vulnerable. You could argue, we should have included children actually in the original trials. But they weren’t the ones that were initially dying. At this point you have almost 4 million children who are reported to have been infected and assume that’s the tip of a much larger iceberg.

You have at least 300 children who’ve died from this infection and estimates are it could be as high as 500. You have multi-system inflammatory disease as another consequence of this infection, which is this frightening, you know, multi-system vasculitis or inflammation of blood vessels. We have enough information to move forward here. I mean, I think it’s reasonable to be cautious, but at this point, you know, we have a raging pandemic. And we have a way out of it, which is this vaccine.

Marshall: So when we look at the side effects, for example, of this phase III trial. As it starts to get rolled out to these 12- to 15-year-olds, what should parents be on the lookout for when it comes to vaccines and specifically the Pfizer vaccine? Are the side effects going to be the same in their kids as it was adults?

Offit: Well, so we knew that in adults that side effects such as fever, headache, joint pain, muscle aches, muscle pain, etc., occurred fairly frequently. Meaning up to about 50% of those who received the vaccine. And it was more likely to occur in the less than 55-year-olds than the greater than 55-year-olds.

I think you can assume that because children do have a robust immune system that they could see these symptoms, or are likely to see these symptoms. And maybe even more frequently, but again that’s all just a product of your immune system. That’s your immune system being activated and getting ready for the fight should you be confronted with SARS-CoV-2.

It’s the first time actually I’ve ever heard of people complaining that they didn’t have side effects because they’re worried that maybe that means they didn’t get an adequate immune response. So I think the immune system is finally getting the attention that it deserves … the praise that it deserves.

Marshall: Dr. Offit, I want you to address something that we’ve heard from some parents. We know that there are rumors in adults about these vaccines causing infertility. As teens, especially this 12 and up group are ones who are going through puberty. Is that something they should be concerned about — how the vaccine might affect puberty in their adolescent children?

Offit: That is actually the most common question I’ve gotten asked. So thank you for asking. Let me tell you where that comes from. There were two researchers that petitioned the European Medicines Agency, which is sort of FDA-like, except in Europe, making this claim.

They said that the SARS-CoV-2 spike protein, this is the protein against what you make antibodies when you’re given a vaccine, that if you look at the sequence of that, that sort of codes for that protein, there are similarities between that and a protein that sits on the surface of placental cells called syncytium-1. Which is a critical protein for placental development. So the thinking was, you know, therefore if you make antibodies to the SARS-CoV-2 spike protein, which is what you want to do with this vaccine. You’re also going to inadvertently be making antibodies against your own placenta.

So, first of all, that was wrong. That phenomenon, which is called molecular mimicry, meaning you’re responding to one protein, but then inadvertently responding to another. It was wrong. I mean, to say that those two proteins are in any sense similar is to say you and I both have the same social security number because they contain the number five. So that was wrong.

Secondly, you could argue a study was done. I mean, when Pfizer, Moderna tested their vaccines, they asked women who were in that trial not to become pregnant. But as Jeff Goldbloom said in Jurassic Park, “life finds a way.” So, 36 people. Roughly three dozen pregnancies occurred during those trials.

Well, if it’s true that inducing antibodies against this SARS-CoV-2 spike protein would affect fertility. Then all of those instances of pregnancy should have been in the placebo group. But they weren’t. They were equally divided among the vaccine group and the placebo group. Eighteen and eighteen. So the vaccine neither enhanced fertility nor affected it negatively.

Also, remember if you’re claiming that antibodies against that surface protein of the virus is dangerous, in any way derogatory, to your pregnancy. We just had about a hundred million people in this country who were infected with this virus. They also made antibodies against that protein.

So what’s happened to the birth rates? There were 3.6 million children born last year, which is slightly down from the previous year, but nothing near what one would have anticipated if this virus affected fertility. So it obviously didn’t affect female fertility in the pregnancy trials and it didn’t affect male or female fertility as this virus sort of swept through this country. So it’s all wrong.

And what’s so upsetting to me is I hear this all the time for women of childbearing age. Saying: this is why I don’t want to get it. It’s wrong. And now it’s just, once you scare people it’s so hard to un-scare them.

Marshall: Yeah. Are you worried though, that fear has already taken grip? And that parents, now that this vaccine is available to their adolescent, prepubescent or pubescent teens, might avoid it?

Offit: Yes. I’m worried about that. I mean, you know, it’s remarkable to me how much the anti-vaccine movement is able to still have an effect.

I mean, I’ve written about the anti-vaccine movement in some form for the last 20 years. And I would have thought that they would never surprise me, but I was wrong.

They still surprise me. I mean, here you have this pandemic that has brought us to our knees economically. That has negatively affected children, certainly psychologically in a matter like never before. I mean, they’re isolated. They’re alone. They don’t get to go to school. They don’t get to be with their friends. They don’t get to go participate in sports or other camps. It’s just awful. And so now you have a way out. You have this excellent, safe, highly effective vaccine, and still they induce fear against the vaccine. There is no floor below which they won’t sink.

Serena Marshall: But let’s be clear here, Dr. Offit. There are a lot of people, a lot of parents, who aren’t anti-vax. They’ve given their kids every recommended vaccine to date. This is a new vaccine. And when they look at the situation that we’re in — the purpose of getting adults or older adults vaccinated was to prevent death.

The purpose of getting, you know, younger adults vaccinated was to prevent serious illness and prevent transmission, as many are also caretakers for their elderly parents. The purpose of getting younger teens vaccinated — is that more to protect the parents? So then they might say, I’m not being anti-vax, I’m being cautious with my child’s health.

Offit: Well, I think you should be cautious for your child’s health. I think you should be skeptical of anything you put into your body or your child’s body. But know this. There’s abundant information now to tell you that the vaccine is safe and effective.

And this vaccine is given to protect children. To protect children from dying because 300 to 500 have died so far this year. To protect children from getting this multi-system inflammatory disease, which I have no doubt is going to at least in a subset of children cause long-term consequences much as Kawasaki’s did. And to protect them from just the normal disease, which is, you know, this severe and occasionally fatal infection of the lung.

So this is to protect children from suffering and being hospitalized and dying. That’s the purpose of this vaccine. So I understand the hesitancy initially. And, you know, the question is never, when do you know everything. You never know everything. The question is when do you know enough?

I mean, there was an article published in Public Library of Science, you know, PLOS, recently by one of the NIH researchers that said something that I think is absolutely right. Which is that over the next few years, you’re going to have two choices, which is either get vaccinated or get infected.

Those are your two choices.

I mean, you know, this virus was mislabeled. When it came out of China it was called a winter respiratory virus and influenza virus that can cause severe and occasionally fatal pneumonia. It is much more than that. This virus causes you to have an immune response against the endothelial cells that line your blood vessels.

This virus causes vasculitis. It causes autoimmunity. And the basic mechanism of that, the pathogenesis of that, it’s not exactly clear. But that it does it, is clear.

I mean, if you asked me, why did I want to get vaccinated? The main reason I wanted to get vaccinated is because I was scared of getting this vasculitis, which I think will have long-term effects.

And I think when you hear about the long-haulers, that’s what you’re talking about. And this is also going to happen at some level in children. So it’s critical that children get vaccinated.

Marshall: So parents who were thinking: “Well, I’m vaccinated. Everyone in my house is vaccinated except my children. I don’t need to worry about them transmitting it to me,” still should be worried about their kids getting it, then?

Offit: Yeah, assuming that they’re not living in a protective bubble. I mean, assuming that they’re going to be outside and interacting with other people, including other children, many of whom may not be vaccinated. Of course you want to protect them. This is your chance to protect them. I mean, parents talk, reasonably, that they’re so upset that children don’t get to go to school and do all the things that they normally get to go to do.

Now you have a way where they can do that safely. I don’t understand the hesitancy here, I don’t.

Marshall: Well, what about the variants? We know that they’re out there. Do they pose a greater risk to children?

Offit: Not, not a greater. It’s only the same risk. But now it’s taken over in this country the so-called B.1.1.7, U.K. variant is definitely more contagious. There’s no evidence, it’s more virulent, no evidence that it’s more likely to infect children than say adults. I think children are now a larger percentage of who’s getting infected because we protected more adults.

But again, both vaccination and natural infection will protect you against at least severe critical disease caused by these variants.

Marshall: With the Pfizer vaccine, is this the exact same vaccine that’s given to adults or are they changing the dosage?

Offit: No, same vaccine given at the same dose and same dosing interval. So it’s 30 micrograms per dose given 3 weeks apart.

Marshall: And will that be the same as we start to see this age down?

Offit: No, so now you’re in the midst of trials down to 6 years of age and in some cases down to 6 months of age. So I think you’re going to see extensive dose ranging studies in those younger kids. I mean, it was easy, I think, with the 12- to 15-year-olds, because there was no reason to think biologically that they were going to be dramatically different than the 16- to 17-year-olds. And we already had data on about 300 people in that age group. So this was easy.

I think it’ll get hit a little harder as we get younger. I would be surprised that we had vaccines that were available, say down to 6 years of age before, early next year.

Marshall: Well, that’s interesting, Dr. Offit. Pfizer was saying they expect to have their 2-11 [year] age group available as soon as September…

Offit: That would be great. Surprising, but great.

Marshall: Why would it be so much harder to get under 6?

Offit: It’s just a matter of how effectively they can recruit. But again, you have to do phase I studies, meaning dose-ranging and dose-interval studies when you go down to the younger age groups to make sure that what is happening in the older age groups does translate to the younger age group.

So I’m glad that Pfizer is optimistic, but again, my sense of this is … I would be surprised, really, even if it was the end of this year. But we’ll see how it plays out.

Marshall: Explain that for us, Dr. Offit, the reason you have to kind of go back to phase I, as you get younger for the children and not just start over at phase III, like we did for the 12 and up?

Offit: When you did these studies in adults, you did phase I trials. So, what Pfizer looked at: 15 micrograms, 30 micrograms, 60 micrograms. Same with Moderna, looking at 25 micrograms, 50 micrograms, 100 micrograms, 250 micrograms. To see what induced an immune response, an excellent immune response, and then go no higher than that.

And I think that with the 12- to 15-year-olds this was easier to do than when you get down to the 6-year-old. We’ll see. We’ll see how it plays out.

Marshall: Looking at these other vaccines that are out there — Moderna, J&J — when would we expect those ones to possibly be available to younger age groups as well?

Offit: I think the Moderna, in terms of the 12- to 15-year-olds … in their case because they’re approved down to 18 years of age. So I think Moderna for the 12- to 17-year-olds should be within weeks. I would think that they would be submitting to the FDA for approval under emergency use authorization.

They were only a few weeks behind Pfizer. Regarding the younger child, I think it’s going to be months longer.

Marshall: Okay. So what does post-market surveillance look like for vaccines in children? Is it the same as it is for adults?

Offit: Yes, of course. I mean, there’s the so-called vaccine safety data link, which is a large length computerized medical records system with, you know, all these major health maintenance organizations that involves about 12 million people in the United States. At least 500,000 of them who are children.

So the minute these vaccines roll out, you look with all these sort of pre-specified possible problems to see whether they’re occurring more commonly in a vaccinated group versus an unvaccinated group.

That’s the advantage of this kind of program.

Marshall: And I want to talk to you for a second, Dr. Offit, about how kids will get vaccinated. Now, a recent national poll by the COVID collaborative and Heart research found 82% of Americans trust their own doctor’s recommendation over the FDA’s. But we know that these vaccines aren’t available yet in doctor’s offices, is that going to negatively impact the ability to vaccinate? As we especially moved down younger and younger and children.

Offit: If you look at the Pfizer vaccine. I think that would be hard to give in a pediatrician’s office. First of all, it has to be stored at between -60° C and -80° C, which means dry ice. Which means you constantly have to make sure that you have dry ice in that office and you’re constantly keeping that at -60° C to -80° C.

That’s hard. It’s hard enough to keep vaccines in a refrigerator, much less in an ultra-cold state. Secondly, once thawed you have a 5-day life in the refrigerator for the Pfizer vaccine. Now they say that they’re coming out with a newer formulation, which will extend the life in the refrigerator. And that’s great.

But for right now, it is a 5-day life in the refrigerator. It also comes in a multidose vial — a five-dose vial. Once you enter that vial, you have 6 hours to give every dose that’s in that vial. I would be surprised if a pediatrician’s office could handle that.

Marshall: We already talked about hesitancy and how it exists, especially with parents and vaccines. You’ve been dealing with it your whole career and trying to convince parents to overcome some vaccine hesitancy. So wouldn’t it help getting these kids vaccinated if we could make it available in their pediatrician’s office, where most parents take their kids for their flu shots?

Offit: Sure. I think it would make it easier. I mean, that’s typically the medical home for a child. But I’m just trying to argue that the storage and handling and delivery characteristics, at least at the Pfizer vaccine make that difficult.

So it may be that instead they would be going to a site that is now mass vaccinating, where they would go to a pharmacy, which would I think be easier. Maybe the pharmacy is going to be the place where the family goes to get vaccinated.

Marshall: Do you see this becoming a regular shot added to the list of vaccines that kids will need going forward?

Offit: It depends obviously how this all plays out. I do think that we are going to be giving this vaccine for a while. We’re going to be giving this vaccine until we are comfortable that this virus has been largely eliminated from the world.

I mean, think about it every year we give a polio vaccine to children, even though we haven’t had polio in the United States since the 1970s. We give it because the virus still exists or is endemic in Pakistan and Afghanistan. Here you have 195 countries in this world, many of whom haven’t given one dose of vaccine.

So I imagine we’re going to be worried about this virus until we feel it’s in control in the rest of the world, which is going to be a while. I think in terms of how long immunity will last, given the level of antibodies that’s produced, given the so-called nature of this cellular immune response, meaning so-called T helper cells and cytotoxic T cells, that usually predicts relatively longer protection.

So I’m going to predict, and we’ll see, whether or not and how long this lasts, but I would predict that immunity would last for a few years.

Marshall: Looking down the line then. Let’s look, 10 years, 15 years. Do you think this will be added into the pediatric vaccinations that are given to babies? Even though right now we’re not vaccinating babies.

Offit: It’s possible, but it also depends on how long immunity lasts. I think we’ll have to see. And it may be that we’re giving constant boost doses and we start with babies and move our way up. It is possible, certainly, that this could be part of the routine schedule. Yes.

Marshall: All right. And speaking of babies, if in a year or so, we have a vaccine that’s approved for infants … a parent who’s breastfeeding might be hesitant to give their kid a vaccine, but they’re looking at how breastfeeding does pass on antibody protection. What would you tell that parent?

Offit: Right. I mean, we have data that if you’re vaccinated and you’re breastfeeding, that you will have antibodies that you will passively transfer onto your babies. First of all, if you were vaccinated prior to the child’s being born, you’ll passively transfer those antibodies through the placenta beginning at about 32 weeks gestation.

And then once born, you can passively transfer antibodies that will then bathe, you know, sort of the upper track with those antibodies that also can protect the child. So you’re protecting yourself and you’re protecting your child.

Remember pregnant women are recommended to receive these vaccines, because now studies clearly show that if you’re pregnant that you’re infected with this virus, you have a 2.5- to 3-fold increased risk of being hospitalized and requiring intensive care as compared to women of the same age who aren’t pregnant.

And now we have studies now of thousands of women who received this vaccine while they were pregnant and they have been followed now through their pregnancy and hundreds of children who have been born, which have now shown that there have not been any problems. Either with the mother during pregnancy or with the child now born as compared to women who also were pregnant, but didn’t get the vaccine.

So I think there’s every reason now to get this vaccine, to protect yourself and your unborn child.

Marshall: And last question for you, Dr. Offit. You’re a father. You write in your book, how one of the scariest speeches you ever gave was speaking in front of your daughter’s class. So, is she getting vaccinated?

Offit: She’s already been vaccinated. She’s in her 20s now. She still scares me, but she’s in her 20s. She’s lovely. But you know, like all fathers, I pretty much do whatever she tells me to do. And my son, too, is in his mid-20s, and he’s fully vaccinated.

Marshall: And If they were in this cohort that was now approved for vaccines?

Offit: If they were 12 to 15 years old, I would vaccinate them in a second.