Colds, bronchitis… seasonal coronaviruses do not immunize children from Covid-19

Children have mildly symptomatic forms of Covid-19 that often go unnoticed. They more rarely develop severe attacks, similar to Kawasaki disease. This population is also sensitive to seasonal coronaviruses, which are responsible for repeated colds and bronchitis every winter.

In a new French study, researchers from the Institut Pasteur, Inserm, AP-HP and the University of Paris show that frequent infections of children with seasonal coronaviruses do not protect them from infection. by the SARS-CoV-2 virus, responsible for Covid-19, or serious forms related to Kawasaki disease. The results have been pre-published on MedRxivJune 30, 2020.

No significant protection against infection

“Seasonal coronavirus infection does not provide significant protection against SARS-CoV-2 virus infection and other associated illnesses such as Kawasaki disease-like syndromecomments Marc Eloit, co-author of the study and head of the Pathogen Discovery Laboratory at the Institut Pasteur. If the Covid-19 virus behaves like seasonal coronaviruses, this observation raises questions about the ability of the population to reach a sufficient level of immunity to prevent the regular reappearance of the disease.he says.

From 1^er march to 1^er June 2020, his team conducted a study in 7 hospitals in Paris and the inner suburbs, with 775 children, 36 of whom presented a syndrome related to Kawasaki disease. The scientists wanted to determine the frequency, type and concentration of antibodies produced by children in response to infection and their ability to neutralize the SARS-CoV-2 virus.

Antibody rate

Conclusion: the prevalence rate of the SARS-CoV-2 virus in patients with no (or few) symptoms was on average 11.7% of the population studied. More than half (69.4%) of these children had never had symptoms suggestive of infection. Neutralizing antibodies were found in 56% of HIV-positive children. More than two-thirds of children with Kawasaki disease-like syndrome were seropositive for the SARS-CoV-2 virus.

“The presence and level of antibodies against the four seasonal coronaviruses, found in 67-100% of children depending on the virus, were comparable between seronegative and seropositive children for the Covid-19 virus, whether these are patients with a syndrome related to Kawasaki disease or those who have had a form that is not (or only slightly) symptomatic”concludes the Pasteur Institute.

Since the appearance of the disease at the end of December in China, the coronavirus has killed more than 530,000 people worldwide, according to the latest report from AFP. More than 11 million cases of infection have been diagnosed in 196 countries and territories.