The coronavirus disease 2019 (COVID-19) pandemic has disrupted childhood vaccinations, including pneumococcal conjugate vaccine (PCV). Evaluating the possible impact on the invasive pneumococcal disease (IPD) incidence associated with a decline in childhood pneumococcal vaccination is important to advocate the PCV programs. Using a deterministic, dynamic transmission model, the differential incidence and burden of IPD in children younger than 5 years in Japan were estimated between the rapid vaccination recovery (January 2021) and the delayed vaccination recovery (April 2022) scenarios for the next 10 years. In our model, the IPD incidence was reduced from 11.9/100,000 in 2019 to 6.3/100,000 in 2020, caused by a reduced transmission rate due to the impact of COVID-19. Assuming a recovery in the transmission rate in 2022 April, the incidence of IPD was estimated to increase with maximal incidence of 12.1 and 13.1/100,000 children under 5 years in the rapid and the delayed vaccination recovery scenarios. The difference in the total IPD incidence between these two scenarios was primarily driven by vaccine serotypes IPD incidence. The difference of incidence was not observed between the two scenarios after 2025. The persistent decline in childhood pneumococcal vaccination rates due to the impact of COVID-19 might lead to an increased IPD incidence and an incremental disease burden.

2019 年冠状病毒病 (COVID-19) 大流行扰乱了儿童疫苗接种，包括肺炎球菌结合疫苗 (PCV)。评估与儿童肺炎球菌疫苗接种下降相关的侵袭性肺炎球菌病 (IPD) 发病率的可能影响对于倡导 PCV 计划很重要。使用确定性的动态传播模型，估计了未来 10 年快速疫苗接种恢复（2021 年 1 月）和延迟疫苗接种恢复（2022 年 4 月）情景之间日本 5 岁以下儿童 IPD 的不同发病率和负担。在我们的模型中，IPD 发病率从 2019 年的 11.9/100,000 减少到 2020 年的 6.3/100,000，这是由于 COVID-19 的影响导致传播率降低所致。假设传输率在 2022 年 4 月恢复，在快速和延迟疫苗接种恢复情景中，IPD 的发病率估计会增加，最高发病率为 12.1 和 13.1/100,000 名 5 岁以下儿童。这两种情况下 IPD 总发病率的差异主要是由疫苗血清型 IPD 发病率驱动的。2025 年之后，两种情景之间的发病率差异未观察到。由于 COVID-19 的影响，儿童肺炎球菌疫苗接种率持续下降可能导致 IPD 发病率增加和疾病负担增加。