Covid-19 and children: study says there is no cross immunity in minors
Having been affected by other coronaviruses would not protect against Covid-19. This is the conclusion of a new French study, which questions the path of cross immunity.
What if a simple cold could immunize us of Covid-19? This is the hypothesis proposed by American researchers, in a study published in the journal Cell last May. This is called cross immunity - it is based on the idea that being infected with another coronavirus can immunize us against Covid-19.
As a reminder, the coronavirus family is made up of many viruses, which are often responsible for a simple cold. According to this study, 40 to 60% of the population would be immune to Covid-19 thanks to past contamination with another coronavirus.
Conclusions just contradicted by researchers from the Pasteur Institute, Inserm, AP-HP and the University of Paris, in a new study published on the scientific pre-publication site MedRxiv.
Covid-19: similar antibody levels in all children
To determine whether an infection with another coronavirus had an impact on immunity to Sars-CoV-2, the researchers analyzed antibody levels against the four seasonal coronaviruses (NL63, HKU1, 229E, OC43) in 739 children ages 0-18.
They were separated into three groups: the children in the first group had positive serology, which shows that they had been affected by Covid-19 and that they had developed antibodies, although they had few or no symptoms. . The second group consisted of participants with symptoms suggestive of multisystemic inflammatory syndrome in children (MIS-C), a rare disease associated with Covid-19, which resembles Kawasaki disease. Children in the third group, meanwhile, had negative serology, a sign that they had never been affected by Covid-19.
Result: all participants had more or less similar antibody levels against the four seasonal coronaviruses. The level of anti-Sars-CoV-2 antibodies was not significantly different in children who had developed a coronavirus infection. Therefore, the researchers concluded that infection with a seasonal coronavirus did not prevent children from being affected by Covid-19.