School of Population Health, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.
The University of Sydney Northern Clinical School, Sydney, New South Wales, Australia.
J Pediatric Infect Dis Soc. 2022 Sep 29;11(9):391-399. doi: 10.1093/jpids/piac038.
Children with chronic medical conditions are at higher risk of invasive pneumococcal disease (IPD), but little is known about the effectiveness of the primary course of pneumococcal conjugate vaccine (PCV) in these children.
A cohort born in 2001-2004 from two Australian states and identified as medically at-risk (MAR) of IPD either using ICD-coded hospitalizations (with conditions of interest identified by 6 months of age) or linked perinatal data (for prematurity) were followed to age 5 years for notified IPD by serotype. We categorized fully vaccinated children as either receiving PCV dose 3 by <12 months of age or ≥1 PCV dose at ≥12 months of age. Cox proportional hazard modeling was used to estimate hazard ratios (HRs), adjusted for confounders, and vaccine effectiveness (VE) was estimated as (1-HR) × 100.
A total of 9220 children with MAR conditions had 53 episodes of IPD (43 vaccine-type); 4457 (48.3%) were unvaccinated and 4246 (46.1%) were fully vaccinated, with 1371 (32.3%) receiving dose 3 by 12 months and 2875 (67.7%) having ≥1 dose at ≥12 months. Estimated VE in fully vaccinated children was 85.9% (95% CI: 33.9-97.0) against vaccine-type IPD and 71.5% (95% CI: 26.6-88.9) against all-cause IPD.
This is the first population-based study evaluating the effectiveness of PCV in children with MAR conditions using record linkage. Our study provides evidence that the VE for vaccine-type and all-cause IPD in MAR children in Australia is high and not statistically different from previously reported estimates for the general population. This method can be replicated in other countries to evaluate VE in MAR children.
患有慢性疾病的儿童患侵袭性肺炎球菌病（IPD）的风险较高，但对于这些儿童中肺炎球菌结合疫苗（PCV）初级疗程的有效性知之甚少。
本队列研究纳入了 2001-2004 年期间在澳大利亚两个州出生的、通过 ICD 编码住院（通过 6 个月龄时的条件确定感兴趣的疾病）或链接围产期数据（针对早产儿）被确定为 IPD 高危（MAR）的儿童，随访至 5 岁，以确定血清型的 IPD 病例。我们将完全接种疫苗的儿童分为在 12 个月龄之前接受 PCV 第 3 剂或在 12 个月龄之后至少接受 1 剂 PCV 的儿童。使用 Cox 比例风险模型估计危险比（HR），并进行混杂因素调整，疫苗有效性（VE）估计为（1-HR）×100。
共有 9220 名患有 MAR 疾病的儿童发生了 53 例 IPD 病例（43 例为疫苗型）；4457 例（48.3%）未接种疫苗，4246 例（46.1%）完全接种疫苗，其中 1371 例（32.3%）在 12 个月龄之前接受了第 3 剂，2875 例（67.7%）在 12 个月龄之后至少接受了 1 剂。完全接种疫苗的儿童的疫苗型 IPD 的估计 VE 为 85.9%（95%CI：33.9-97.0），全因 IPD 的估计 VE 为 71.5%（95%CI：26.6-88.9）。
这是第一项使用记录链接评估 MAR 条件下 PCV 有效性的基于人群的研究。我们的研究提供了证据，表明澳大利亚 MAR 儿童中疫苗型和全因 IPD 的 VE 较高，与先前报道的一般人群的估计值无统计学差异。这种方法可以在其他国家复制，以评估 MAR 儿童的 VE。
