Expert Q&A: What We Know About the COVID-19 Vaccine and Children

If you're a parent, you likely have a lot of questions about the COVID-19 vaccine, especially when it comes to giving it to your children. There are two vaccines currently available that have been approved for emergency use by the Federal Drug Administration (FDA). Pfizer's COVID-19 vaccine has been approved for those 16 years and older and Moderna's COVID-19 vaccine has been approved for those 18 years old and older. There's still a lot to learn about the vaccine when it comes to kids, but we hope this information provided by Mary Suzanne Whitworth, M.D., medical director of infectious diseases at Cook Children's, is helpful as you begin to consider vaccinating your children against COVID-19 when it is released for them.

What is mRNA, and how does it differ from other vaccines we are familiar with?

Messenger RNA is a new type of vaccine technology. It has been studied for a couple of decades and has been researched for things like cancer vaccines. Messenger RNA is a molecule that we all make billions of copies of in our bodies every day.

The way this vaccine works is that messenger RNA is in the syringe and is injected into your arm. That messenger RNA is taken up by muscle cells and other white blood cells in the area. The messenger RNA tells your body to make the spike protein from the virus. When your body makes the spike protein, that's recognized as foreign, it doesn't belong there. Your immune system learns what the spike protein from coronavirus is, makes a response and develops antibodies, while other parts of your immune system learn about the spike protein. The coronavirus has the spike protein, and if you're exposed to it later, your body says, “Oh, this is that spike protein, I know what to do about this,” and binds it and prevents infection.

How was the COVID-19 vaccine made so quickly and how does that timeline compare to the development of other vaccines? 

The speed of this vaccine is one of the real miracles of modern science. The difference between this vaccine’s development and other vaccines like Prevnar, Menactra or the hepatitis A vaccine is that the steps for those were done one at a time over about six years. For the COVID-19 vaccine, all the steps were all done simultaneously.

If you're developing a Prevnar or a hepatitis B vaccine, you:

• Figure out what kind of vaccine you want to make, a live virus vaccine or a bacterial protein.
• Develop the vaccine.
• Conduct a Phase I trial to look at the dose.
• Conduct a Phase II trial where you look at about 500 or a thousand people, and you give them the vaccine to see if it's safe. 
• Conduct a Phase III trial of 10,000 or 20,000 people to see if it works.
• Get FDA approval.
• Make the vaccine. That may take a year.
• Distribute the vaccine. That may take another six to 12 months.

For Operation Warp Speed, a couple of things worked in our favor. Messenger RNA technology was available and the machines and scientists were already in the labs. Normally, a Phase II trial would take a year or two to get a hundred or more volunteers to enroll. It could take three years to get another 10,000 or 15,000 volunteers. With there being an active pandemic going on, there were more than 30,000 volunteers overnight.

To see if the vaccine works, there has to be enough disease in the community to cause enough infection to see if the vaccine is better than the placebo, or if they're equal. Normally, that may take a couple of years. In this case, the pandemic was so bad that we could see right away that placebo recipients had a lot of COVID-19 and the vaccine recipients didn't. That endpoint was reached quickly and very safely.

Also through Operation Warp Speed, the vaccine was being tested at the same time it was being manufactured and while plans were being made for distribution. Operation Warp Speed also paid for vaccines to be developed by companies, even if they were determined to be ineffective or didn't work. You'd never get a vaccine company to make a hundred million doses of a vaccine and take that financial risk, but Operation Warp Speed paid for that. The fact that there was plenty of disease and that everything was done at the same time allowed for very safe development of the vaccine in about 10 months. I've gotten both of my doses now. I think it's a very safe vaccine.

Is it normal for a vaccine to be released while still in a clinical trial?

I'm not sure that a vaccine has ever been released for EUA (Emergency Use Authorization) before. The reason that is done is that when there's been a pandemic declared, the FDA is allowed to use a vaccine or monoclonal antibodies or an antiviral medication if it's believed that the benefit outweighs the risk and it's deemed to be safe from everything that's known about it. The Phase III trials are still ongoing, which means that for the 40,000 people in the trial for Pfizer that were vaccinated, they are still being watched and are still collecting data.

Would we know by this stage in the trial, if there were major side effects with the COVID-19 vaccine?

You cannot be 100% sure. They watched about 20,000 people who got the vaccine for two full months and looked at every adverse event that happened to those people. When you look at the side effects of all kinds of vaccines throughout history, all of the serious side effects happen within about six to eight weeks. It's very rare to have a side effect from a vaccine after that time if it happens at all. We know that influenza vaccine can cause Guillain-Barre syndrome, which is a temporary paralysis requiring hospitalization. It’s a terrible side effect that happens in about one out of a million doses of influenza vaccine. That happens within six weeks. We know that with the measles, mumps, rubella (MMR) vaccine, you can get low platelets that happens at about three weeks. We know that with any vaccine or medicine, you can have anaphylaxis, which is a severe life-threatening allergic reaction that happens within two hours. For the vaccines that are known throughout history, there's no significant major side effect that's long-term. The only one I can think of is measles vaccine. There can be chronic measles infection that can lead to problems even a decade later, but that's a live virus vaccine. The COVID-19 vaccine has no virus in the vaccine, that would not even be a consideration for this. 

Have there been studies specifically on the safety of the COVID-19 vaccine in children?

There have been some children, 12 years of age and older, in the vaccine trials, but it's not enough that it has been licensed for children yet. There are some trials currently enrolling pediatric patients with Pfizer and Moderna.

Do you know when the COVID-19 studies regarding children will be complete? 

I don't know for sure. I think everyone is hopeful that we'll have some results by the spring, in the next three or four months.

When will the COVID-19 vaccine be available for children? 

There will have to be trials that document safety in children, and document that it works. Then it will go through the FDA, just like it went through for the adult COVID-19 dosing in December 2020. Then the FDA will give a ‘yes’ or ‘no.’ The Advisory Committee for Immunization Practices (ACIP) will then give a recommendation for a time frame and which children should receive the vaccine. I hope it will be here before the summer, but I don't know.

What benefit is there in vaccinating a healthy child if the statistics show that 99% of children recover from COVID-19?

You could say that for chicken pox, and for a lot of things that kids get vaccinated for. I think when you look at a pandemic, and you look at the transmission of the virus, you have to stop transmission of the virus. Even though children are not great transmitters, they still do spread the virus. You would want to add them in safely if the vaccine is safe for children. You would want to immunize children to remove another place for the virus to land. You want as much of your population as possible to be immune to the virus, to slow down community numbers, and stop the pandemic spread. 

What should parents who have children with underlying health conditions know about the COVID-19 vaccine?

Parents should talk to their child’s pediatrician. They need to see if the underlying condition puts the child at increased risk for problems with the COVID-19 disease and make that decision with their doctors. There is not a tremendous amount of data in immunocompromised hosts or other conditions, but there's some data and they'll need to talk to their doctors about their child's specific situation. Keeping in mind that if their child catches COVID-19, that may be riskier than the vaccine, there's always a choice. If you decide that you don't want to get the vaccine, you are saying ‘yes’ to the ongoing risk of infection. Depending on your child’s condition, that may be a reasonable choice.

Are there any medical conditions that would prevent a child from getting the COVID-19 vaccine?

You don’t want to get the vaccine if you are allergic to the vaccine components. There's not a known, proven medical condition where the diagnosis would prevent getting the vaccine. You don't want to get the vaccine if you've had anaphylaxis to the ingredients in the vaccine. If you've had anaphylaxis to the first dose of the vaccine, you wouldn't get the second one. 

Do we know what ingredients in the COVID-19 vaccine causes allergic reactions?

It is thought that part of the allergic reaction may be the polyethylene glycol or the PEG that's in the vaccine. Some individuals are allergic to polysorbates, and that can cross-react with polyethylene glycol. People that are allergic to either of those two compounds would be a contraindication for them to get the vaccine.

It's a very small vaccine. It contains the messenger RNA and a fatty or a lipid capsule around that little piece of RNA. There is a list of what's in that capsule on the Pfizer, CDC and FDA websites. There are no adjuvants nor preservatives in the COVID-19 vaccines that are currently available.

One of the complications of COVID-19 in children is MIS-C. What is MIS-C? 

MIS-C stands for multisystem inflammatory syndrome due to COVID-19 disease. If you catch the SARS-CoV-2 virus, you can get an asymptomatic infection or a symptomatic infection with a cough, fever, and shortness of breath. There are some children who, about the third or fourth week after they start their infection, will develop an inflammatory syndrome. The first part of their initial infection may not have any symptoms at all, and they can still get this inflammatory syndrome. Children with MIS-C have high fevers and appear very ill. They have very abnormal blood values for inflammation, and they have evidence that multiple organ systems are involved. They may have inflammation of the heart, which we can pick up with lab tests. They may have inflammation of the kidneys or the liver. They often will have a rash on their skin, pink eye and/or red swollen lips. When these children are admitted to the hospital, they frequently require intensive care before they get better. 

How should MIS-C be considered when weighing the risk and benefit of the COVID-19 vaccine in children? 

MIS-C is a high morbidity rate, meaning children are terribly ill, often in the intensive care unit (ICU), and occasionally on life support. You don't want your child to get MIS-C, it's serious. For reasons that are not clear to me, the mortality rate is very, very low, which we're grateful for. There aren't very many diseases like that. These children are ill, and the huge majority of them live through that, but not always unscathed. Some will have ongoing damage to the coronary arteries or the heart. When the data comes out about children, the hope is that it will show that those who are vaccinated are not only are protected from COVID-19, but protected from getting MIS-C. That data should be forthcoming. 

What are the side effects and adverse reactions of the COVID-19 vaccine?

There are a group of side effects that are part of the reactogenicity or part of your system saying, “Hey, I need to do something with this new spike protein floating around my body.” These side effects occur within the first 48 to 72 hours after the vaccine and are typically headache, muscle aches, fever, chills, joint pains, and sometimes redness and swelling where they get their vaccine. This occurs in about 20% or 30% of people after the first dose, and it might even be 40% of the people after the second dose.

The other side effects from the vaccine include anaphylaxis where you have a life-threatening allergic reaction within two hours of the vaccine dose, and it often happens within 15 to 30 minutes. You're more at risk for that if you've had anaphylaxis to something else in the past. It's thought that anaphylaxis happens in about one out of 90,000 doses of the vaccine. I have read and have not seen any deaths from that. Everyone has recovered and gone home from the hospital, and they can't get their second dose. That's probably the most serious side effect. Then there are some things that we're not sure about whether or not they're from the vaccine.

If you watch 20,000 people for two months, you can expect some of them will have a heart attack. Some of them will have a stroke. Some of them will be killed in a car wreck. All of those things happen. When you watch a large group of people for two months, it's not always easy to tell if the vaccine triggered the problem that happens. We know that in the Pfizer trial, there were four cases of Bell's palsy, which is paralysis of one side of the face that almost always completely resolves, but not every time. There were no cases of Bell's palsy out of 17,000 people that got the placebo. But four cases out of 17,000 is not above the baseline rate that you'd expect. Nobody knows what to make out of that information. There were about 12 cases of appendicitis after the vaccine and eight cases after the placebo, a tiny difference, but not different than the background rate. There are some side effects that you'll read about that are hard to determine if they're related to the virus, but for sure the anaphylaxis is in some cases. For sure, the reactogenicity side effects can be seen from the vaccine. 

If a child has a history of allergic reactions, should they avoid the COVID-19 vaccine? 

If they have an allergic reaction to something not related to the vaccine, a food allergy, a penicillin allergy, a bee sting allergy, they can still get the vaccine once it's approved for children, but their 15 minute observation period will be 30 minutes instead. Any child who’s had an anaphylaxis type of reaction to anything, needs to talk to their doctor first before they sign up for the vaccine and go over that with them.

What research is going on to track long-term side effects of the COVID-19 vaccine? 

For the people that are in the Phase III trials, it's my understanding that those companies will follow those recipients for two years, and they've already been following them for six or seven months. One of the things that you have to keep in mind about long-term follow-up for these vaccines is that in the current pandemic, you can't justify waiting another year to release these vaccines. With 3,000 or 4,000 deaths a day in the country, it only makes sense for something that's been proven to be safe to be released because the benefit of the vaccine at this point outweighs the risk of getting COVID-19. 

Does the COVID-19 vaccine change your DNA?

No. The vaccine injects messenger RNA into your muscle cell, or your white blood cells nearby. It never enters the nucleus where the DNA is. It doesn't integrate itself into your DNA. The messenger RNA particle is very fragile and it's not even around for very long, it disintegrates and goes away very quickly. This is why the vaccine has to have a deep freeze, and if you thaw it out for too long, it doesn't work. If you open the freezer for too long, and it gets at the wrong temperature for too long, it's inactive. It's a pretty fragile particle, and there's no evidence that it integrates into your DNA. 

Does the COVID-19 vaccine cause infertility? 

No. There were pregnancies during the vaccine trials, and there's no reason to think that it would cause infertility. If you think about it, if you make antibodies to the spike protein from the vaccine, that's exactly what you're going to do if you catch the COVID-19 infection. Either way, you get antibodies to the spike protein. If the COVID-19 infection doesn't make you sterile, the vaccine wouldn't either. 

Is the COVID-19 vaccine safe for pregnant women? 

I recommend that pregnant women speak with their physicians and make their own decision about the vaccine. If pregnant women want the vaccine, they can get it. The American College of Obstetricians and Gynecologists has said there's not any reason not to vaccinate pregnant women. What is recommended is that pregnant women talk to their physicians and make their own decision. Pregnant women have to keep in mind that if they catch COVID-19 during the pregnancy, they fare worse than if they're not pregnant.

Are there any other common myths about the COVID-19 vaccine?

There's no government implanted chip. I've heard the rumor that you get implanted with a chip when you get vaccinated and that the government is going to track you. All I can say is if you have a smartphone, there's probably already someone tracking you.