In the midst of the Omicron wave, is it really useful to vaccinate children?

Admittedly, there is a delay in ignition on the vaccination of children in France. Only 6% of 10 to 11 year olds and 1.9% of 5 to 9 year olds have received at least one injection against Covid-19. Against 51.8% of small Spaniards and 28% of their Italian comrades. “We must advance the vaccination of children aged 5 to 11, which started slowly,” warned Jean Castex last Thursday.

Beyond the strong practical constraints (a small number of centers offer pediatric vaccination, children are not available except on weekends, etc.), many parents do not hide their doubts. Is it really useful to vaccinate children? 20 minutes answers five questions that parents may ask themselves.

Why vaccinate when there are very few serious cases?

Children very rarely have serious Covid. So why immunize them against a bad cold, especially in such a high epidemic phase, with an extremely contagious and mild Omicron variant? “This vaccination of children is still useful, insists Romain Basmaci, general secretary of the French Society of Pediatrics and head of the pediatric service at Louis Mourier hospital (AP-HP). There are more and more children infected with Omicron, more than in previous waves. There are still a few severe forms of Covid-19. “Some children can develop an acute Covid, similar to the disorders of adults with respiratory distress and high fever. According to Santé Publique France, even if the hospitalizations of children for Covid-19 have increased markedly in recent weeks, “the 0-17 year olds, (21.5% of the French population), represent between 3 and 5% of Covid-19 patients. 19 hospitalized, stable proportion during the second half of 2021”.

Public Health France diagram highlighting that the number of child hospitalizations for Covid increased significantly in January 2022. – Public Health France

Second subject: PIMS (Pediatric inflammatory multisystem syndrome) or pediatric multi-systemic inflammatory syndrome. Between five and six weeks after Covid-19, which can be very mild, the child’s immune system develops an abnormal response to this virus. According to Public Health France, the number of cases of PIMS since March 2020 amounts to 879, including 796 related to Sars-Cov-2. In addition, 71% of these children, especially aged 3 to 11, are hospitalized in critical services. However, unlike adults, 80% of children who developed PIMS were in good health and without declared comorbidity. “We now know that vaccination protects against these PIMS”, reassures Romain Basmaci. Indeed, an AP-HP study reveals that out of 107 patients under 18 suffering from this syndrome, “33 were over 12 years old (31%) and therefore eligible for vaccination, 26 of them were not vaccinated, 7 had received one dose of vaccine, none had received two doses”.

A third argument is also advanced on the individual benefit of this vaccination. “We still have little information on the effect of Omicron on long Covid, underlines Sandrine Sarrazin, Inserm Research Officer at the Marseille-Luminy Immunology Center. How to assess the impact of this long-term variant when we only have one month of follow-up? A certain percentage of infected children have long Covids and this is very disabling. I don’t see why we would play Russian roulette, we can end up with 5,000 hospitalized children, if it was mine, I would prefer to vaccinate it…”

Is this vaccine safe?

Vaccination of children only started in France a month ago. On the other hand, other countries started the injections at the beginning of November. “We now have the necessary hindsight with American and Israeli studies on several million children who received the vaccine without warning, proving that this vaccine is well tolerated”, continues Romain Basmaci. Indeed, the favorable opinion of the High Authority of Health to open vaccination to all children between 5 and 11 years old is based on several reassuring pharmacovigilance studies. In particular “the data published by the North American VAERS (Vaccine Adverse Event Reporting System), which reported, until December 10, 2021, 3,233 adverse events, out of more than 7 million doses administered. The majority of them (97%) were not serious. Two deaths occurred in children with serious medical histories and 14 cases of myocarditis were reported, 8 of which were confirmed. For the 5 cases where information was available, the myocarditis resolved and the children recovered completely. »

Why vaccinate when it may be the last wave?

The peak of the Omicron wave could soon be behind us: hospitalizations, including in sheaves, are stagnating or falling. Our Minister of Health even launched: “maybe this is the last wave”. So why protect your child today against possible future epidemic outbreaks? “We are unable to say if it is the last wave”, corrects Romain Basmaci. And the many experts remind us how much this virus has (unfortunately) surprised us. Not to mention the Omicron BA.2 sub-variant which is starting to get talked about…

Why not wait for a suitable vaccine?

Pfizer’s pediatric vaccine was made from the initial strain, which appeared in China in 2019. And we now know that it takes three doses to be well protected against Omicron. Imagine, with tight timing, that a child receives his first dose on February 1, his second on February 22, and a third three months later, on May 27. Doesn’t it make more sense to wait, when Pfizer has promised its Omicron vaccine for March?

For Alain Fischer, “Mister Vaccination” of the government, this wait-and-see attitude is not a good calculation for three reasons. “Children immunize themselves better than adults,” recalls the immunologist. We can hope that the primary vaccination, which moreover does not have a zero effect vis-à-vis Omicron, will be more effective on the youngest. We cannot therefore extrapolate: it takes three doses for adults, the same for children. What we know is that vaccination protects against Delta infection by 85% in children. But we should have additional information on Omicron coming from the United States soon. Second reason: “there is always some Delta in our country”, even if this variant has clearly become a minority. “Finally, it is possible that we will have an Omicron vaccine in the spring, but for adults only, not pediatrics. “We will then have to wait a little longer for a new formula adapted to children, tested, studied, marketed. “Given the current situation of contaminations and hospitalizations, even imperfect, the best vaccine is the one that is available”, adds
Eric Billyresearcher in immuno-oncology in Strasbourg and member of the collective Du Côté de la Science.


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