Children more unlikely to produce antibodies

A small study found that compared with adults, a higher proportion of children did not produce antibodies in response to SARS-CoV-2 infection.

About the study:

• The study was carried out between May and October, 2020 at the Royal Children’s Hospital, Melbourne, Australia.
• The study looked at the ability of adults and children to produce antibodies when infected with the Wuhan strain of the virus.
• Whether children would exhibit the same characteristics in the case of the Delta and Omicron variants, where people tend to have far higher viral loads, is not known.
• The study recruited children and adults infected with SARS-CoV-2 and their household members, and samples were collected from the throat and nose to detect the virus; blood samples were collected to measure humoral responses.
• The mean cycle threshold (Ct) value for adults was 24.1 while it was 28.5 in the case of children.
• The smaller the Ct value, the higher is the viral load.
• However, the researchers say that when the Ct value was less than 26, both adults (90.9%) and children (80%) developed antibodies.
• The findings of this cohort study suggest that among patients with mild COVID-19, children may be less likely to have seroconversion than adults despite similar viral loads.
• This finding has implications for future protection after SARS-CoV-2 infection in children and for interpretation of sero-surveys that involve children.
• A lack of seroconversion [lack of antibodies] may result in a higher susceptibility to reinfection. This hypothesis may have important implications on the transmission of SARS-CoV-2 in the community and the public health response.