Age-related peculiarities of antibody-mediated humoral immune response following SARS-CoV-2 infection

Abstract

Thousands of articles were published about the COVID-19 disease and hundreds about the immune response. But still little is known about the features of SARS-CoV-2-specific immunity in elderly. The aim of current research was to evaluate the age-related peculiarities of antibody mediated humoral immune response following SARS-CoV-2 infection. Our study presents an intriguing divergence from the classical concept of immunosenescence, where aging has been assumed to cause poor antibody responses, reduced or inefficient vaccination, and overall blunted immune responses in elderly people. Our findings were opposite to some of these expectations; participants aged over 60 expressed elevated titers of anti-SARS-CoV-2 antibodies in comparison to younger adults. Analyzing the data of relative neutralization and avidity of anti-SARS-Cov-2 (S) antibodies we propose that although older adults produce a higher quantity of antibodies, their functional efficiency appears relatively reduced exhibiting lower neutralizing capacity and binding strength per antibody compared to younger adults. We can assume that the immune system of the elderly may require a higher level of antibody production to obtain a comparable level of protection. Our findings highlight the intricate nature of immune responses in convalescent older adults. This has particular relevance to understanding immunity and vaccine responses in different age groups.