COVID-19 vaccination for children aged 5-11 years

On November 25, the European Medicines Agency issued a positive recommendation for the Pfizer/BioNTech COVID-19 vaccine for children aged 5-11 years. What dose will children be vaccinated with and how many times?
Ernest Kuchar, MD, PhD: A dose of 10 micrograms has been established. The vaccine will be administered on a 0-21-day schedule. The schedule is the same as for adults, only the dose is three times lower. This has been proven to be enough to produce immunogenicity in children. The antibody concentration in the 5-11 age group after a 10 microgram dose is the same as in 16-25 year olds after a 30 microgram dose.

After that, will children also be given a third booster dose?
E.K.:  This has not been studied, but it is to be expected.

So what was the subject of the vaccine study in children 5-11 years old?
E.K.: It was in the nature of immuno-bridging. This means a bridging study that evaluates the immunogenicity of the vaccine. Our goal, therefore, was to select a vaccine dose for pediatric age and to verify that the antibody concentration after vaccine administration was sufficient. We evaluated 2000 children. 1305 of them received the vaccine, the rest a placebo. On this occasion, we learned that the effectiveness of the formula in this age group is 91 percent. There have been very few cases of COVID-19. 16 in the unvaccinated group and only 2 in the vaccinated group. I emphasize, however, that we did not test for efficacy per se. It wasn't necessary. We've known for a long time that vaccinations are effective, as evidenced by the fact that more than one billion adults worldwide have already received the vaccine.

Were there any side effects observed in the studies you are referring to?
E.K.:  In the case of vaccinations, adverse reactions can be divided into two groups. The first is symptoms due to vaccine tolerance and mechanisms of action. It is worth recalling that the vaccine uses natural immune mechanisms. So the body reacts to it as if it was sick. Hence the malaise and fever. There is also often pain at the injection site. Such symptoms are normal, they do not give permanent consequences, so we do not need to be afraid of them. The incidence in children is similar to that of adults. Our study showed that at a dose of 10 micrograms in the youngest age group, the safety profile is comparable to that in adults or adolescents at a dose of 30 micrograms. We still have a second group of side effects. These are rare and serious side effects, such as myocarditis. We did not observe such side effects in our study. This is obvious when you consider that they occur at a rate of 1 in 200,000 vaccinated people. The size of our study was too small to detect such rare situations.

What other formalities need to be fulfilled before vaccination can begin in Poland and when will this happen?
E.K.: Now the European Commission must just approve the vaccine for use. However, I think it won't take long. Getting children vaccinated is a matter of days or so. There remains the issue of organization. The Minister of Health announced that a vaccine has already been ordered. These are multi-dose packets, so measuring 10 micrograms is not a problem. In conclusion, nothing stands in the way for the vaccination of children start already in December.

At the beginning of the pandemic, children were said to suffer from COVID-19 far less often than adults, and if they did get sick it was usually mild.
E.K.: The virus is new, so any of us is susceptible. Why should children be the exception here? Of course, they were sick less often than adults at first, but that was largely due to our behavior. In the first phase of the pandemic, schools were closed, so children were protected, in fact they did not leave home. It was the adults who did the shopping and if they couldn't work remotely - they went to work. It is therefore logical that there were more cases among adults. Now adults have already been through COVID-19 either/or and are vaccinated. The illnesses have "passed on" to children.

What is the situation at the Paediatric Teaching Clinical Hospital UCC MUW, are there more patients with COVID-19?
E.K.: Our hospital has never seen so many patients with COVID-19 before. Considering the number of sick children, it can already be said that the fourth wave is the worst. Many children become moderately ill. However, there are some that pass COVID-19 hard. These severe illnesses of children represent just a fraction of a percent. However, if there are a lot of infected children and that huge number is multiplied by a fraction of a percent, you get a lot of absolute numbers.

At what age do children get sick the most?
E.K.: Either infants or teens, especially those with risk factors such as obesity, are most likely to be admitted to the hospital. It has long been known that excess weight weakens immunity. Adipose tissue is hormonally active and has pro-inflammatory effects. A large abdomen, on the other hand, puts additional pressure on the lungs, which is why obese people, as well as pregnant women, go through COVID-19 harder.

Why is it important to vaccinate children ages 5-11 against COVID-19?
E.K.: Because for this age group it is not a benign disease at all. Just compare it to chickenpox, whooping cough (pertussis), rotavirus, influenza or tetanus, the diseases against which we vaccinate. It appears that the threat from COVID-19 is now greater. Moreover, our observations suggest that 1 in 500-1000 children, even if mildly ill, develop PIMS, a multisystem inflammatory syndrome associated with COVID-19. The syndrome is severe in children and threatens to cause cardiac complications and often ends with a stay in the intensive care unit.

Why  vaccinating children, not just against COVID-19, is controversial in our country?
E.K.: I would rather say that Poles are divided on this issue, and it has to do with the appearance of a lot of harmful, false information on the Internet. Today anyone can post whatever they want on social media. This is a great field for fanatics of various views, which can be spread effectively and cheap. As long as the message is attractive in form or the content has strong emotional appeal, plenty of people will read it. Unfortunately, not everyone can separate the wheat from the chaff. Many people treat the internet as a source of knowledge. As a result, they form opinions and make wrong decisions on the basis of false information. It is worth noting here that as parents we are very careful about the safety of our children. If we hear arguments for and against vaccination, even if the latter are false, without knowing anything about medicine, we intuitively withhold the decision to vaccinate. 

On the other hand, there is a perception in the public mind that vaccines are primarily for children…
E.K.: And I would argue with this view. This is a belief dating back to the 1950s, when there were more children than seniors in the age structure of Poles. Back then, vaccinations were indeed for children. However, a lot has changed since then. Today we have brand new vaccines and a society that is aging. Influenza, COVID-19 or pneumococcal vaccinations are for the entire population. Especially for those who need it most, namely children, but also for seniors and the chronically ill.

In your opinion, will the vaccination rate against COVID-19 in 5-11 year olds be high?
E.K.: I don't think it's going to be any bigger than in a group of teenagers. Poles are likely to divide again. Those who have been vaccinated and have vaccinated their older children, perhaps will vaccinate their younger children as well.

How to convince hesitant parents to vaccinate their children when the opportunity arises?
E.K.: Parents certainly won't be convinced by TV commercials featuring unknown people saying "Let’s vaccinate.” General Practitioners can have an important role here. If a pediatrician that parents trust recommends vaccination, there is a good chance that the child will be vaccinated. When I talk to the parents of my patients, I always emphasize that I myself am vaccinated, as well as my children, my mother and my wife. I follow what I recommend, according to what I know well. And I do so with complete conviction.

Interview by Iwona Kołakowska, MUW