New Zealand, like many countries, reported reduced community transmission of Group A Streptococcus (Strep A) and other non-vaccine preventable respiratory pathogens as a consequence of COVID-19 pandemic restrictions. Subsequent to the relaxation of these restrictions, surges in infections caused by these pathogens were documented, often exceeding pre-pandemic levels. This large-scale study investigated whether reduced pathogen exposure during the pandemic resulted in immunity gaps that may have contributed to these surges. It utilised samples from long term plasma donors collected by the New Zealand Blood Service between January 2020 and September 2023 and involved screening >4500 individual donations. Building on our prior assay systems for Strep A and SARS-CoV-2 serology, a new multi-pathogen bead-based assay comprised of major antigens from Strep A (Streptolysin-O, SpnA, DNaseB and SpeA), respiratory syncytial virus (RSV; glycoproteins G and F), endemic human coronaviruses (hCoV; NL63 and HKU1 spike), and SARS-CoV-2 (spike) was developed for detection of pathogen specific antibodies (IgG). Both paired analysis and mixed effect modelling showed significant reductions in IgG to antigens from Strep A, RSV, and hCoV over the 3-year period, with average, antigen-specific decreases ranging from 6-20%. In contrast, IgG for SARS-CoV-2 spike increased exponentially over the same time period. The observed reduction in IgG to Strep A and other respiratory pathogens likely reflects reduced exposure to these endemic agents during the pandemic, and may have contributed to the pronounced infection surges in 2023.