Vaccination Boosts Immune Memory in People Previously Infected With COVID
A new study finds that vaccinating people who've already had COVID-19 strengthens their immune response across a broad range of B cells—the antibody-producing cells critical to fighting infection. The finding has implications for vaccine strategy and could inform how public health authorities design booster campaigns for maximum protection.
Originaltitel: Vaccination of SARS-CoV-2-infected individuals expands a broad range of clonally diverse affinity-matured B cell lineages
<title>Abstract</title> <p>Vaccination of SARS-CoV-2 convalescent individuals generates broad and potent antibody responses. Here, we isolated 459 spike-specific monoclonal antibodies (mAbs) from two individuals who were infected with an early ancestral strain of SARS-CoV-2 and later boosted with mRNA-1273. We characterized mAb genetic features by sequence assignments to the donors’ personal immunoglobulin genotypes and assessed antibody neutralizing activities against ancestral SARS-CoV-2, Beta, Delta, and Omicron variants. The mAbs used a broad range of immunoglobulin heavy chain (IGH) V genes in the response to all sub-determinants of the spike examined, with similar characteristics observed in both donors. IGH repertoire sequencing and B cell lineage tracing at longitudinal time points revealed extensive evolution of SARS-CoV-2 spike-binding antibodies from acute infection until vaccination five months later. These results demonstrate that highly polyclonal repertoires of affinity-matured memory B cells were efficiently recalled by vaccination, providing a basis for the potent antibody responses observed in convalescent persons following vaccination.</p>