The prospect of the authorization of the Pfizer / BioNTech vaccine in 12-15 year olds reactivates the debate on the vaccination of minors against COVID-19. What is the state of knowledge? What are the issues?
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It’s for when?
The first regulatory approvals for the Pfizer / BioNTech vaccine for adolescents are imminent, but it will then be up to each country to decide whether it includes minors in its vaccination schedule.
In the United States, a request for an extension to 12-15 year olds has been made. The green light from the Federal Medicines Agency (FDA) could fall as early as next week.
The European Medicines Agency (EMA) has started the “fast-track assessment” of data submitted by Pfizer and BioNTech, with a decision expected in June.
This would make it possible to vaccinate adolescents “at the latest during the summer holidays”, judged the German Minister of Health, Jens Spahn, while in France, his counterpart, Olivier Véran, considers that he “does not there is no urgency ”.
The two laboratories have filed a similar request with the British regulator and plan to do the same in other countries.
What data do we have?
The question of the effectiveness on minors of vaccines, so far tested in adults, is little doubt: “in general, children have a much better immune response than adults,” told AFP the infectious disease specialist Odile Launay, member of the COVID vaccine committee in France.
“On the other hand, legally and ethically, we are obliged to have safety data more specific to this population,” she added.
The applications filed by Pfizer / BioNTech are based on the results of a phase 3 clinical study on 12-15 year olds, announced at the end of March, showing according to the laboratories “a 100% effectiveness” of the vaccine to prevent the disease.
The vaccine was also “well tolerated and the side effects were generally consistent with those observed” in 16-25 year olds, they say.
The other studies on minors are ongoing, and there is no data yet available on the use of COVID vaccines under the age of 12.
Moderna announced in mid-March the launch of trials of its vaccine on 6,750 children aged 6 months to 11 years in the United States and Canada.
Pfizer and BioNtech also have an ongoing study for children ages 5 to 12, with results expected in July.
AstraZeneca had launched a trial on 6-17 year olds in February, but its partner, the University of Oxford, announced its suspension on April 6, pending results on the rare risk of atypical thrombosis observed in adults. At this stage there was “no concern about the safety of the pediatric clinical trial,” according to the British university.
A collective immunity issue
Children and adolescents are less exposed to severe forms of the disease. But “some children can have serious forms”, such as those with leukemia or who have immune deficiencies, observes Odile Launay.
But the challenge of vaccinating the youngest is above all the protection of the rest of the population.
There is now data showing that “vaccination with the Pfizer vaccine is very likely to reduce transmission”, and “it can be hypothesized that the same is true for all RNA vaccines” such as Moderna’s, said. to AFP Alain Fischer, the French Vaccines Mister.
But “if we rely on the level of contagiousness of the British variant, it would probably be necessary that 75% of the total population, children included, be vaccinated” to achieve collective immunity, he added. If we do not vaccinate minors at all, it means vaccinating “80% to 85%” of adults, says the immunologist.
However, it is normal for the subject to be debated, because “going to vaccinate a population that does not present a risk of causing complications in order to obtain this collective immunity, that can be discussed”, underlines Odile Launay.
“This is an issue in countries where viral circulation is still very high. But I do not think that it makes sense where there is hardly any more virus, judge Beate Kampmann, professor of pediatric infectious diseases at the London School of Hygiene and Tropical Medicine, questioned by AFP.
In a situation where the virus would circulate little and where most fragile people would already be vaccinated, “we would avoid more suffering by leaving the vaccines to countries where there are many people seriously ill and dead, like in India, rather than by vaccinating our adolescents, ”she adds.