As a follow-up to a previous study, we investigated vaccine effectiveness (VE) of 23-valent pneumococcal polysaccharide vaccine (PPSV23) against invasive pneumococcal disease (IPD) among 1,254,498 persons >65 years of age as part of a vaccination program in Denmark during April 2020–January 2023. We assessed VE by using a Cox regression model and adjusted for age, sex, and underlying conditions. Using nationwide data, we estimated a VE of PPSV23 against all-type IPD of 32% and against PPSV23-serotype IPD of 41%. Because this follow-up study had more statistical power than the original study, we also estimated VE against IPD caused by PPSV23-serotypes excluding serotype 3; serotype 3; serotype 8; serotype 22F; PPSV23 non-PCV15 serotypes; PPSV23 non-PCV20 serotypes; and IPD over time. Our findings suggest PPSV23 vaccination can protect persons >65 years of age against IPD caused by all serotypes or serotype groupings, except serotype 3.

作为先前研究的后续研究，作为丹麦疫苗接种计划的一部分，我们在 1,254,498 名 65 岁以上人群中调查了 23 价肺炎球菌多糖疫苗 (PPSV23) 针对侵袭性肺炎球菌疾病 (IPD) 的疫苗有效性 (VE) 2020 年 4 月至 2023 年 1 月期间。我们使用 Cox 回归模型评估 VE，并根据年龄、性别和基础条件进行调整。使用全国数据，我们估计 PPSV23 对所有类型 IPD 的 VE 为 32%，对 PPSV23 血清型 IPD 的 VE 为 41%。由于这项后续研究比原始研究具有更强的统计效力，因此我们还估计了 VE 对 PPSV23 血清型（不包括血清型 3）引起的 IPD 的影响；血清型3；血清型8；血清型22F； PPSV23非PCV15血清型； PPSV23非PCV20血清型；和随时间变化的 IPD。我们的研究结果表明，PPSV23 疫苗接种可以保护65 岁以上的人免受除血清型 3 之外的所有血清型或血清型分组引起的 IPD。