Contralateral second dose improves antibody responses to a 2-dose mRNA vaccination regimen

BACKGROUND Vaccination is typically administered without regard to site of prior vaccination, but this factor may substantially affect downstream immune responses.METHODS We assessed serological responses to initial COVID-19 vaccination in baseline seronegative adults who received second-dose boosters in the ipsilateral or contralateral arm relative to initial vaccination. We measured serum SARS-CoV-2 spike–specific Ig, receptor-binding domain–specific (RBD-specific) IgG, SARS-CoV-2 nucleocapsid–specific IgG, and neutralizing antibody titers against SARS-CoV-2.D614G (early strain) and SARS-CoV-2.B.1.1.529 (Omicron) at approximately 0.6, 8, and 14 months after boosting.RESULTS In 947 individuals, contralateral boosting was associated with higher spike-specific serum Ig, and this effect increased over time, from a 1.1-fold to a 1.4-fold increase by 14 months (P
Source: Journal of Clinical Investigation - Category: Biomedical Science Authors: Source Type: research