Medical validation: November 2020

What do we really know about the risk of contamination from the COVID coronavirus – 16 in schools ? Are children really less affected than adults? What masks to wear at school? And during recess? What about the reinforced protocol? Update with Dr Gérald Kierzek, emergency doctor.

At the start of the pandemic, it was feared that children would be important vectors of the coronavirus, by analogy with other viral diseases such as influenza. Then the opposite idea took hold, with studies suggesting they were not very contagious.

But ” if we look at the data from the (scientific) literature, it is not so clear that that “, epidemiologist Dominique Costagliola told AFP. The only thing that is certain right now is that children and adolescents under 16 years only represent 1% to 3% of COVID cases 1 and that, according to Public Health France, “ the severe cases and deaths are exceptional ”in this category.

Regarding their role in the spread of the epidemic, studies contradict each other and none can say for the moment that they are less vectors of the virus than adults . Indeed, as indicated by epidemiologist Zoë Hyde in an article published at the end of October by the Medical Journal of Australia 2 , number of studies according to which children do little to infect their relatives ” were carried out during periods of confinement ” and therefore of low circulation of the virus , which may have skewed their results. Especially since recently, several studies carried out in the United States, India or South Korea have challenged the idea that children are not very contagious.

Coronavirus: Are children less contaminating than adults? According to Dr Gérald Kierzek, emergency physician, “ most studies show the same rate of seroconversion in children as in adults. The only thing we are sure of is that children do less severe forms ”.

Thus, a meta-analysis published at the end of September in the journal Jama Pediatrics 3 concluded that “ there is little evidence that children play a lesser role than adults and adolescents in the transmission of SARS-COV-2 at the population level . ” In their introduction, the authors therefore state that “the th degree to which children and adolescents under 20 years are infected and transmit the coronavirus is an unanswered question. ”However,“ these data are essential to inform national plans to relax measures social distancing, including the reopening of schools . ”

However, some scientists are more adamant. This is the case of those of Massachussets General Hospital 4 . According to them, children could indeed carry a significant viral load – similar to that of adults – whether or not they have symptoms. Thus at the end of August, the main author of this study affirmed that “the s children (being) a possible source of transmission of the virus, (this) should be taken into account in the decision to reopen the schools. ”

Several other studies go in the same direction, some even affirming that the youngest carry a higher viral load than the adults and could, therefore, be “super contaminators”. This is the case of a study published at the end of July in the journal Jama Pediatrics 5 , which reveals that the rate of genetic material found in the nose of children under the age of 5 was 04 To 100 times higher than among older people. A South Korean study 10 however recently contradicted this data by claiming that , if the children of 04 To 16 years old transmit the virus as much as adults, young people under 9 years old would be less contaminating.

Is school a place of coronavirus contamination? Faced with the number of contradictory studies, it is therefore difficult to navigate.

Yet, according to the World Health Organization (WHO) 6 , although we know, At present, “ misjudges the role played by children in the transmission of the virus. (…) the reduced number of outbreaks reported among faculty or associated staff suggests that the spread of COVID – 16 in educational structures may be limited. ”In France, the Institut Pasteur is of the same opinion 7 . He says, following a study carried out in April 1315 on 1 160 people involved in a school in Crépy-en-Valois (26) that “l are children from 6 to 10 years are more infected in the family environment than at school. “” Infected children did not transmit the virus to other children, teachers or others school staff ”says Arnaud Fontanet, first author of the study, head of the Epidemiology of emerging diseases unit at the Institut Pasteur and professor at Cnam.

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According to Daniel Lévy-Bruhl, of Public Health France ” the risk related to schools is not zero, no one can say that, but the share of transmission within schools compared to transmission in the rest of the community is low “. The expert warns against a magnifying glass effect: ” The number of schools opened around the world is extraordinarily large. not much”. On the other hand, we talk a lot ” about the few schools where there have actually been epidemic phenomena – some of which can be explained by conditions favorable to the transmission of the virus -, this which gives a somewhat biased impression of the risk associated with schools “.

Yet“ How can we know that the transmission did not take place at school? ”asks Gérald Kierzek. The asymptomatic cases being numerous, it is indeed difficult to know where the infection was contracted and who contracted it first before being transmitted to other members of the family … At the end of October, a study of Centers for Disease Prevention and Control in the United States (CDC ) 8 has shown that people with coronavirus infect approximately half of their family members. Although adults appear to be more contagious than children, the authors concluded that: ” significant transmissions have occurred whether the index patient was an adult or a child” .

Wearing a mask at school from 6 years old: category 1 masks only Affected this fall by a second wave of the epidemic, several European countries, including France, had to reconfigure themselves, but left schools open. Faced with the hypothesis of a strong contagiousness of children, the French government has chosen to impose the mask on students from 6 years old, against 10 previously. A decision which was accompanied by a reinforced health protocol.

Note that international bodies such as WHO and UNICEF believe that the decision to impose mask for young people from 6 to 10 years should be based on several factors, including the “ intense risk of transmission in the area where the child resides ” 9 or “ the child’s ability to use a mask correctly and safely ”. But according to Gérald Kierzek, “ the mask is a false security. ” Same story on the side of pediatric societies : according to Dr Fabienne Kochert, pediatrician and president of AFPA , “ Wearing a mask is restrictive and of moderate effectiveness if it is not accompanied other measures. ”

And“ even though they are less contagious than people from years and adults, children have a lot of contact with their comrades and with adults. And since they are many, with a lot of contacts, that can make a lot of cases of contamination “, notes Dominique Costagliola. In addition, experts point out that the risk associated with the school depends on the local epidemic situation: ” It is very important to understand that schools do not operate in isolation, they are part of a community “, underlines Maria Van Kerkhove.

Since February 8 2021, only category masks 1- filters at 69% – are accepted in schools. The purpose of the new directive is to limit the risk of the virus spreading, in particular due to the arrival of English variants and South African , more contagious, on the territory. Children will no longer be able to wear a “homemade” mask, but only surgical masks, of the FFP2 type or in fabric, category 1 approved.

Masks: except during recess The government announced on 16 last June that masks would no longer be mandatory during recess. It is the face in the air that the children will be able to enjoy e their break times. Jean-Michel Blanquer then declared at the microphone of France Inter, Thursday morning: “It’s a good thing” , adding that “many children and adolescents found it painful to have to wear the mask during recess” .

Coronavirus: a reinforced protocol in schools In order to limit the risk of the spread of variants, the health protocol is reinforced in schools: if a student is infected with a South African or Brazilian variant, the entire class will be closed and all students and their teachers will have to be tested. Even more restrictive, a student in the event of contact with a person of his family (parents, brother, sister) who has contracted one of these variants will also see his entire class closed, the other students and teachers will then have to be tested.

Soon saliva tests in schools and universities “ In my opinion, the The only way to secure schools would be to carry out preventive tests regularly: children undergo antigenic tests twice a week through the school infirmaries and those who are positive are isolated “, suggests Gérald Kierzek. Although this is not, for the moment, the solution chosen by the government, during the press conference on February 4 2021, Olivier Véran announced that saliva tests will be set up in schools and universities ” upon return from school holidays ”

More comfortable than a swab in the nose, this test – which requires spitting out a little saliva in a test tube – will allow “mul increase collective screening operations “in schools. Note, however, that saliva tests are not rapid tests – like antigenic tests, the result of which is obtained in about twenty minutes. ” The examination then continues in the laboratory in the same way as for the tests that you know “, a specified the Minister of Health.

Saliva tests in schools will be carried out with the written consent of parents. The results must be returned before 8 a.m. the next day so that the child does not come to school in the event of a positive test. Kindergarten and primary students will have priority, nasopharyngeal tests can be particularly unpleasant for them.


1-Constitution of the World Health Organization
2- NHS UK conditions