Fort Worth, Texas,
15:53 PM

Q&A: Pediatrician Discusses COVID-19 Vaccine Safety, Efficacy and Trials in Children

Dr. Terk COVID-19 Vaccine Q&A

Jason Terk, M.D., answers questions about COVID-19 vaccine and children

COVID-19 vaccines are widely considered essential to returning to some sense of normalcy and an end to this pandemic. In the latest findings of the probability-based online Gallup Panel Survey, 63% of Americans say they are willing to be immunized against the disease.

But many people question the safety of a novel immunization for a novel virus, especially parents with young children. Moderna recently announced plans to begin testing its coronavirus vaccine in children between the ages of 12 and 17, while Pfizer and AstraZeneca began their pediatric trials in October.

We were able to talk to Jason Terk, M.D., physician at Cook Children’s Pediatrics Keller Parkway and a nationally known advocate for vaccines, who answered a few questions about the COVID-19 vaccine.

Tell us about the COVID-19 vaccine and why people should feel safe receiving it.

The vaccine is really showing a lot of promise because we've gotten data that shows that the efficacy (that's how well the vaccine works at protecting against COVID-19 disease), is much more effective than what we might've expected. We were hoping to get something around 70% and the two vaccinations that are being considered for emergency use authorization have efficacy of about 95%, which is really fantastic. I think that that bodes well for the potential of these vaccinations to make a real difference for us.

While trials in children are just beginning, should parents go ahead and get the vaccine?

Well, the quantity of vaccinations that we have available is going to be limited initially. The CDC, FDA and the state health departments are all working together to determine what priority groups need to be getting it first. The elderly nursing home population, healthcare workers, and first responders are going to be the first individuals recommended to get the vaccination. Obviously we need to protect the health care workers so that we can continue to do our jobs providing care to our patients. Unless you have some serious underlying health condition that makes you high risk for complications from COVID-19, you will not as a parent be among the first groups of individuals  recommended to get the vaccination. But once we have plenty of supply, I certainly encourage parents to get the vaccination for themselves.

When is the vaccine going to be available for children?

Trials in children are only just beginning. We need to prove that the vaccine is just as effective and just as safe in children because children are not little adults. We also need to make sure that it works as well for them too. I have no reason to expect that it will not be as effective for children. It's going to be important to stay tuned for that. Once the vaccine is available for myself, I'm definitely going to be in line to get it. And I am unreservedly optimistic about its impact for myself and for the rest of us.

What gives you that confidence that it is a safe choice for you to get the vaccine?

In medicine, we're data driven and we have really good data that shows its effectiveness, as well as what the safety profile is with the 30-40,000 individuals who were involved in the Phase 3 trials. Right now, what we've seen from a safety point of view, is that it is producing some side effects that are very similar to other vaccinations out there that are routinely recommended and they're fairly mild for most people. The two vaccinations that are currently under consideration for emergency use authorization require two doses. One of them requires two doses separated by 21 days. The other one requires two doses that are separated by 28 days. It appears that after that second injection, that maybe about half of the individuals have some side effects like achiness and, and maybe sore joints and, and some injection site soreness and things like that, but it doesn't last very long. It's generally gone after a few days. We've had the pandemic going on now for about a year. And we've had these vaccines that are under consideration now for about six months in the clinical trials. People in those clinical trials will be followed for at least 2 years to monitor for any problems. I have no reason to expect that there will be safety concerns.

Will children receive the same vaccine as adults?

Very good question. We won't really know the answer to that until the clinical trials are completed in children. Sometimes kids require lower doses of the same vaccination that we need to get as adults. And sometimes they get the same dose. What you're looking for is to get the desired therapeutic point of protecting against the disease at the lowest dose to minimize side effects. So that's what they'll be working on for kids too.

Should people who have already had COVID-19 get the vaccine?

So the current recommendations coming from the CDC is that prior COVID-19 disease should not be a determining factor about whether you should get the vaccine, because we do not know how long natural disease will give you immunity. It certainly gives you some protection for a period of time, but how long that lasts? We really don't know. Probably because of limited supply, individuals who were shown to definitely have had COVID-19 will probably not be the first ones that will be recommended to get the vaccination. That’s getting kind of ironed out right now and we'll get more specific information on those recommendations in the next several weeks I expect.

Where should people look for more information as they make the decision on getting the vaccine?

I think that it's important to talk about information and how people get information. Unfortunately, there is organized resistance against vaccinations generally, and against efforts to try to vaccinate the population against COVID-19 specifically. Consumers of this information need to know that that those sorts of agenda-driven organizations are working to prevent the end of the pandemic. We really need to be very careful and make sure that the things that we're reading or watching on social media are evidence-based. These vaccinations are going through the same – and even greater – rigorous processes and scrutiny that all the other vaccinations that we have gone through. I have every confidence that this is going to be a game changer for the human population. We all need to get vaccinated and support this challenging effort.

Are you hopeful that a COVID-19 vaccine can help end the pandemic?

Absolutely. This is our way forward to try to get back to normal. It's not going to be an immediate thing, but it's going to be a lot quicker now that we have such effective vaccinations. It will take some time for us to really get back to normal as we know it, but we're getting there.


For more information about vaccines and COVID-19, visit

For the latest on how COVID-19 is impacting kids and Cook Children’s work to protect them, visit the medical center’s newsroom at


Get to know Jason Terk, M.D.

Dr. Terk is a Cook Children's pediatrician at Keller Parkway. Dr. Terk earned his medical degree from University of Texas Medical Branch in Galveston, Texas. He completed his residency in pediatrics at Mayo Graduate School of Medicine (Mayo Clinic) in Rochester, Minnesota. His interests include public policy advocacy for children's health issues, focusing primarily on vaccines. Dr. Terk is board-certified in pediatrics. New and exisiting Cook Children's Keller pediatrician office patients can make an appointment by calling 817-968-1200 or through the button below to access Cook Children's Patient Portal.