辉瑞25价儿童肺炎球菌疫苗公布2期数据：对第3型血清型抗体水平约为现有疫苗15倍，已推进至3期试验
辉瑞公司（Pfizer）10月24日在 Washington 举行的 IDWeek 2026 年会上，以口头报告形式公布其在研25价肺炎球菌结合疫苗（25vPnC，代号 PF-07872412）的2期临床试验详细数据：健康婴儿完成四剂接种后，该疫苗对全部25种血清型均产生强劲免疫应答，安全性与耐受性与现有的20价肺炎球菌结合疫苗 PREVNAR 20 相当，研究中未发现与疫苗相关的严重不良事件。
本轮数据最受关注的是第3型血清型。该血清型占美国5岁以下儿童侵袭性肺炎球菌疾病病例的10.6%，且历来是现有疫苗应答偏弱的一型。结果显示，第3剂接种后1个月，25vPnC 组的第3型抗体几何平均浓度为 PREVNAR 20 组的8.8倍（4.22 对 0.48）；第4剂加强针后1个月升至约15倍（13.85 对 0.92）。辉瑞称该候选疫苗采用了专门针对第3型血清型的新一代结合技术。
在 PREVNAR 20 覆盖的20种血清型之外，25vPnC 新增15A、23A、23B、24F、35B 五种血清型，估计可多覆盖约30%的美国儿童侵袭性肺炎球菌病例；25种血清型合计约占美国5岁以下儿童同类病例的84%。这项随机对照2期试验（登记号 NCT06524414）以健康婴儿为对象，在出生后2、4、6个月及12至15个月时各接种一剂，并与 PREVNAR 20 对照。
辉瑞高级副总裁兼疫苗首席官 Annaliesa Anderson 表示：「这些令人鼓舞的数据，是在 PREVNAR 系列疫苗25多年来保护儿童免受严重肺炎球菌疾病侵袭的进展之上取得的。通过扩大血清型覆盖，并对历来棘手的第3型血清型应用新一代技术，这款候选疫苗有望为儿童提供迄今最广泛的侵袭性肺炎球菌疾病防护。」
辉瑞表示，该数据支持25vPnC继续推进3期研发：儿童方向已有3项3期研究于2026年内启动，合计最多6,830名受试者随机接种25vPnC或 PREVNAR 20，另有一项三批次一致性3期研究已完成入组；成人方向则计划在与监管机构沟通后，于2026年底前把一款第五代35价候选疫苗推进临床。25vPnC目前仍属在研产品，尚未获任何监管机构批准。
Pfizer's 25-Valent Pediatric Pneumococcal Vaccine Shows Phase 2 Data: Serotype 3 Antibody Levels About 15 Times Higher Than Current Vaccine, Now in Phase 3
Pfizer on October 24 presented detailed Phase 2 results for its investigational 25-valent pneumococcal conjugate vaccine candidate, PF-07872412 (25vPnC), in an oral session at IDWeek 2026 in Washington, D.C. In the study, a four-dose series of 25vPnC elicited robust immune responses against all 25 serotypes in healthy infants, with safety and tolerability comparable to PREVNAR 20 and no related serious adverse events identified.
The headline finding involved serotype 3, which accounts for 10.6 percent of invasive pneumococcal disease in U.S. children under five and has historically been a weak spot for existing vaccines. One month after dose 3, serotype 3 antibody geometric mean concentrations were 8.8-fold higher with 25vPnC than with PREVNAR 20 (4.22 versus 0.48); one month after the dose 4 booster, they were approximately 15-fold higher (13.85 versus 0.92). Pfizer said the candidate uses next-generation conjugate technology designed specifically to strengthen the serotype 3 response.
Beyond the 20 serotypes covered by PREVNAR 20, 25vPnC adds five more (15A, 23A, 23B, 24F and 35B) estimated to account for roughly 30 percent of additional pediatric invasive pneumococcal cases in the U.S.; together, the 25 serotypes are responsible for approximately 84 percent of such cases in children under five. The randomized Phase 2 trial (NCT06524414) dosed healthy infants at 2, 4, 6 and 12 to 15 months of age.
"These encouraging data build on more than 25 years of progress in protecting children from serious pneumococcal disease with PREVNAR vaccines," said Annaliesa Anderson, Ph.D., Senior Vice President and Chief Vaccines Officer at Pfizer. "By expanding serotype coverage and applying next-generation technology to the historically challenging serotype 3, this candidate aims to extend the substantial reductions in disease that existing vaccines have achieved. If successful, it could help provide children with the broadest protection against invasive pneumococcal disease to date."
Pfizer said the data support its ongoing Phase 3 program: three pediatric Phase 3 studies began earlier in 2026 with up to 6,830 participants randomized to 25vPnC or PREVNAR 20, and enrollment in a three-lot consistency study is complete. For adults, the company plans to move a fifth-generation 35-valent candidate into clinical development by the end of 2026, pending regulatory alignment. The 25vPnC candidate remains investigational and is not approved by any regulator.
来源：GSM·美国（原文链接）
图片来源：图：实验室人员抽取疫苗药液（资料图）。照片：John Keith 摄，公共领域，经 Wikimedia Commons。Photo: A laboratory worker draws vaccine from a vial (file photo). Photo by John Keith, public domain, via Wikimedia Commons.
