Novel strategy for Poxviridae prevention: Thermostable combined subunit vaccine patch with intense immune response

Poxviruses gained international attention due to the sharp rise in monkeypox cases in recent years, highlighting the urgent need for the development of a secure and reliable vaccine. This study involved the development of an innovative combined subunit vaccine (CSV) targeting poxviruses, with lumpy skin disease virus (LSDV) serving as the model virus. To this end, the potential sites for poxvirus vaccines were fully evaluated to develop and purify four recombinant proteins. These proteins were then successfully delivered to the dermis in a mouse model by utilizing dissolvable microneedle patches (DMPs). This approach simplified the vaccination procedure and significantly mitigated the associated risk. CSV-loaded DMPs contained four recombinant proteins and a novel adjuvant, CpG, which allowed DMPs to elicit the same intensity of humoral and cellular immunity as subcutaneous injection. Following immunization with SC and DMP, the mice exhibited notable levels of neutralizing antibodies, albeit at a low concentration. It is noteworthy that the CSV loaded into DMPs remained stable for at least 4 months at room temperature, effectively addressing the storage and transportation challenges. Based on the study findings, CSV-loaded DMPs are expected to be utilized worldwide as an innovative technique for poxvirus inoculation, especially in underdeveloped regions. This novel strategy is crucial for the development of future poxvirus vaccines.