The amount and quality of antibodies to COVID-19 vary with age, according to a study suggesting that the differences in the clinical manifestations of the disease in children compared to adults, “may be due in part to age-related immune responses.”
Studies conducted since the start of the pandemic suggest that minors are more likely to have mild symptoms and a lower risk of developing severe respiratory disease than adults, but until now it was not known how the immune response differed between the different groups elderly.
The authors examined whether the quantity and quality of antibodies against the coronavirus differ between children, adolescents and adults, for which they evaluated 31,426 antibody tests conducted in New York between April 9 and August 31, 2020, according to the study published by JAMA (Journal of the American Medical Association).
Although seroprevalence was “similar” in pediatric and adult patient populations, an evaluation focusing on quantitative and qualitative profiles of antibodies to SARS-CoV-2 revealed “key differences” in humoral antibody responses based on age.
The results indicate that younger children have higher levels of total and functional IgG antibody (immunoglobulin G) activity than adolescents and young adults aged 19-24.
“Our data may partially explain the lower overall symptom and severity rate in children infected with SARS-CoV-2,” write the authors of Weill Cornell Medicine in New York.
The study evaluated positivity rates of SARS-CoV-2 antibodies and IgG levels, as well as total antibody (TAb) and surrogate neutralizing antibody (SNAb) activity.
Children showed higher median IgG, TAb and SNAb activity levels compared to adolescents and young adults.
Adolescents also had a higher median of the values studied than young adults, while people aged 19 to 30 years had the lowest IgG levels.
The team believes that since antibody responses differ in different age groups, strategies targeting this factor for disease detection and treatment, as well as vaccine development, may be warranted.
The lower incidence of symptoms and lower disease severity in pediatric patients raises the possibility that this population may be “an important reservoir of viral transmission in the community.”
Therefore, screening school-aged children, even those with no apparent symptoms or exposure, could be an important step in curbing the pandemic, the authors note.