Kids produce different antibodies in response to Covid-19: Study

The differences in antibodies suggest the course of SARS-CoV-2 infection and immune response is distinct in children and most children easily clear the virus from their bodies, the study published in 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.

"In kids, the infection course is much shorter and probably not as disseminated as in adults. Kids may clear this virus more efficiently than adults and they may not need a strong antibody immune response to get rid of it," Farber added.

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 centre 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 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 neutralising activity, while all adults, including young adults in their 20s, produced neutralising antibodies.

The sickest adults had the most neutralising 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.