Antibodies Against SARS-CoV-2 Do Not Cross-React with Endemic Coronaviruses in a Pediatric Population: Data from a Bangladesh Cohort.

Summary: Why do children often get milder cases of COVID-19 than adults? Scientists have long wondered if kids have a secret weapon. One popular theory was that because children catch so many common colds (which are often caused by different types of coronaviruses), their immune systems might mistake the COVID-19 virus for a common cold and fight it off more effectively. This is called "cross-reactivity."

However, a new study from Bangladesh challenges this idea. Researchers looked at blood samples from 100 children taken before and during the pandemic. While nearly half of the children caught COVID-19, those who had previously battled common cold coronaviruses didn't have any extra antibody protection against the new virus. In short, fighting off a playground cold doesn't seem to give kids a head start against COVID-19. The mystery of their resilience lies elsewhere.