肺炎鏈球菌感染症與疫苗的現況和展望

Current Status and Future Perspectives of Pneumococcal Disease and Vaccination

肺炎鏈球菌是社區型肺炎、腦膜炎與菌血症的重要病菌。從7價結合型疫苗（7-valent pneumococcal conjugate vaccine, PCV7）問世，到PCV13的推廣，已有效降低兒童與成人肺炎鏈球菌疾病的發生率，近五年又有PCV15、PCV20與PCV21的發展，新冠疫情防疫期間發生率更大幅下降，但疫情後又逐漸回升。目前在台灣及全球，突破性感染以血清型3、19A為主，非PCV13血清型如23A、15A、15B/C、34、35等占比逐漸增加，抗藥性方面，部分非PCV13血清型抗藥性逐漸上升。新一代高價數結合型疫苗提供更廣泛血清型涵蓋率，臨床試驗顯示PCV15、PCV20與PCV21多能達到對共同血清型的不劣性，且對部分新增血清型具優越性。目前美國疫苗接種委員會更新接種指引，擴大高價數結合型疫苗於兒童、高風險族群與50歲以上成人的使用，以提升整體保護力。未來仍需持續監測血清型變化、抗藥性趨勢及真實世界的疫苗效益，以優化肺炎鏈球菌感染症防疫策略。

Streptococcus pneumoniae is a major pathogen responsible for community acquired pneumonia, meningitis, and bacteremia. Since the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) and the rollout of the 13-valent vaccine (PCV13), the incidence of pneumococcal disease has declined significantly in both children and adults. Over the past five years, 15-valent, 20-valent, and 21-valent conjugate vaccines have been developed. During the COVID-19 pandemic, pneumococcal disease incidence rates dropped markedly due to public health measures, but gradually increased after restrictions were lifted. Currently, in Taiwan and globally, breakthrough infections are predominantly caused by serotypes 3 and 19A; while non-PCV13 serotypes such as 23A, 15A, 15B/C, 34, and 35 have been increasing in proportion. Antimicrobial resistance has also risen among some non- PCV13 serotypes. Newer higher-valent conjugate vaccines offer broader serotype coverage. Clinical trials have shown that PCV15, PCV20, and PCV21 generally prove non-inferiority for shared serotypes and demonstrate superior immunogenicity for certain additional serotypes. The U.S. Advisory Committee on Immunization Practices (ACIP) has recently updated its recommendations; expanding the use of higher-valent conjugate vaccines among children, high-risk groups, and adults aged 50 years and older, to enhance overall protection. Continued surveillance of serotype distribution, antimicrobial susceptibility, and vaccine effectiveness will remain essential for optimizing pneumococcal disease prevention strategies.