Core-shell microcapsules compatible with routine injection enable prime-boost immunization against malaria with a single shot

Inadequate booster uptake threatens the success of immunization campaigns as seen with the recently rolled-out R21 malaria vaccine. The ability to administer both prime and boost immunizations with a single injection would therefore save lives and alleviate healthcare burdens. We present a platform for delayed delivery of the booster dose that is scalable with existing technology, easily injectable, and protective against malaria in vivo. Using chip-based microfluidics, we encapsulated the R21 malaria vaccine in polymer microcapsules that release their content weeks to months post-injection. Co-injecting microcapsules with the priming dose of the R21 vaccine elicited strong antibody responses in a mouse model and provided 85% of the protection of a standard prime-boost schedule. If confirmed in humans, these results would pave the way for rapid deployment of single-shot prime-boost vaccination, an urgently needed global health intervention.加强针接种覆盖率不足正威胁免疫接种项目的成效，新近推出的R21疟疾疫苗（R21 malaria vaccine）便是典型例证。若能通过单次注射完成初免与加强免疫的全流程，便可挽救生命并减轻医疗系统负担。本研究提出一种可延迟递送加强针的技术平台，该平台可依托现有技术实现规模化生产、易于注射，且在体内可抵御疟疾。本研究借助基于芯片的微流控技术（chip-based microfluidics），将R21疟疾疫苗封装于聚合物微囊中，该微囊可在注射后数周至数月内释放所载内容物。将微囊与R21疫苗的初免剂量共同注射，可在小鼠模型中诱导强烈的抗体应答，其防护效力达到标准初免-加强免疫方案的85%。若该结果在人体研究中得到验证，将为单次注射式初免-加强免疫接种的快速推广铺平道路，这是一项亟需的全球卫生干预举措。