Invasive Pneumococcal Disease diminish during the onset of COVID-19 in Japan between 2019 and 2022

Invasive pneumococcal disease (IPD) is a severe infection caused by Streptococcus pneumoniae. This study explores the influence of COVID-19 on IPD occurrence in Japan by using the time trend analysis. We found that the IPD trend changed dramatically after the emergence of COVID-19; first, the number of IPD cases decreased. Second, the seasonality of IPD disappeared after the COVID-19 pandemic. Interestingly, the number of IPD cases increased between the waves of COVID-19