Introduction

Since 2010, 10-valent (PCV10) and 13-valent pneumococcal conjugate vaccines (PCV13) have been available as part of infant national immunization programs. Belgium is as one of the few countries that implemented PCV13 (2007–2015), switched to PCV10 (2015–2018) and then switched back to PCV13 (2018–present) after observing increases in disease. We assessed the impacts of both historical and prospective PCV choice in the context of the Belgian health care system and used this experience to validate previously developed economic models.

Methods

Using historical incidence (2007–2018) of pneumococcal disease for Belgian children aged < 16 years, observed invasive pneumococcal disease (IPD) trends from surveillance data were used to estimate future disease in a given PCV13- or PCV10-based program. We compared observed incidence data with two modeled scenarios: (1) the 2015 switch to PCV10 and (2) a hypothetical continuation of PCV13 in 2015. Finally, we explored the potential impact of PCV choice from 2019 to 2023 by comparing three scenarios: (3) continued use of PCV10; (4) a switch back to PCV13; (5) a hypothetical scenario in which Belgium never switched from PCV13.

Results

Model predictions underestimated observed data from 2015 to 2018 by 100 IPD cases among ages < 16 years. Comparing observed data with scenario 2 suggests that PCV13 would have prevented 105 IPD cases from 2015 to 2018 compared with PCV10. Switching to PCV13 in 2019 would avert 625 IPD cases through 2023 compared with continuing PCV10. Scenario never switching from PCV13 would have resulted in a reduction of 204 cases from 2016 to 2023 compared with switching to PCV10 and switching back to PCV13.

Conclusion

The findings from this study suggest that previously published modeling results of PCV13 versus PCV10 in other countries may have underestimated the benefit of PCV13. These results highlight the importance of continually protecting against vaccine-preventable pneumococcal serotypes.

中文翻译：

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验证用于估计转换肺炎球菌结合项目影响的新预测方法：来自比利时的证据

介绍

自 2010 年以来，10 价 (PCV10) 和 13 价肺炎球菌结合疫苗 (PCV13) 已作为婴儿国家免疫计划的一部分提供。比利时是少数几个实施 PCV13（2007-2015 年）、转为 PCV10（2015-2018 年）并在观察到疾病增加后转回 PCV13（2018 年至今）的国家之一。我们在比利时医疗保健系统的背景下评估了历史和未来 PCV 选择的影响，并利用这一经验来验证先前开发的经济模型。

方法

使用比利时 16 岁以下儿童肺炎球菌病的历史发病率（2007-2018 年），从监测数据中观察到的侵袭性肺炎球菌病 (IPD) 趋势用于估计特定基于 PCV13 或 PCV10 的计划中的未来疾病。我们将观察到的发病率数据与两种模拟情景进行了比较：(1) 2015 年切换到 PCV10 和 (2) PCV13 在 2015 年的假设延续。最后，我们通过比较三种情景探讨了 2019 年至 2023 年 PCV 选择的潜在影响：( 3）继续使用PCV10；(4) 切换回 PCV13；(5) 比利时从未从 PCV13 转换的假设情景。

结果

模型预测低估了 2015 年至 2018 年 100 例年龄 < 16 岁的 IPD 病例的观察数据。将观察到的数据与情景 2 进行比较表明，与 PCV10 相比，PCV13 将在 2015 年至 2018 年期间预防 105 例 IPD 病例。与继续使用 PCV10 相比，2019 年改用 PCV13 将在 2023 年之前避免 625 例 IPD 病例。与切换到 PCV10 和切换回 PCV13 相比，从 2016 年到 2023 年，从不从 PCV13 切换的情景将减少 204 例病例。

结论

这项研究的结果表明，先前在其他国家发布的 PCV13 与 PCV10 的建模结果可能低估了 PCV13 的益处。这些结果强调了持续预防疫苗可预防的肺炎球菌血清型的重要性。