Children infected with the COVID-19 produce weaker antibodies and fewer types of them than adults do, suggesting they clear their infection much faster, reports a new study.
The differences in antibodies suggest the course of SARS-CoV-2 infection and an immune response is distinct in children, and most children easily clear the virus from their bodies, the study published in the journal Nature Immunology reported.
"Our study provides an in-depth examination of SARS-CoV-2 antibodies in kids, revealing a stark contrast with adults," said study author Donna Farber from Columbia University Vagelos College of Physicians and Surgeons in the US.
One of the striking manifestations of the Covid-19 pandemic is that the majority of children cope well with the virus while older people struggle.
Among the 47 children in the study, 16 were treated for Multisystem Inflammatory Syndrome in Children or MIS-C, and 31 children of similar ages had tested positive for the virus after visiting the medical center for the treatment of other conditions.
Half of the children without MIS-C had no Covid-19 symptoms.
The 32 adults in the study ranged from severely affected patients admitted to the hospital to those with the milder disease who recovered at home.
Both groups of children produced the same antibody profile, the study found, which differed from that of adults.
Compared with adults, children produced fewer antibodies against the virus's spike protein, which the virus uses to infect human cells.
The children's antibodies had the least neutralizing activity, while all adults, including young adults in their 20s, produced neutralizing antibodies.
The sickest adults had the most neutralizing activity.
In contrast to adults, children also produced very few antibodies against a viral protein that is only visible to the immune system after the virus infects human cells.
"That suggests that in kids, the infection doesn't really spread a lot and doesn't kill a lot of their cells," Farber said.
Also, the antibody responses found in children do not suggest that children will have a weaker response to a vaccine, the researchers stressed.