Lyophilized monkeypox mRNA lipid nanoparticle vaccines with long-term stability and robust immune responses in mice.

The World Health Organization (WHO) has recently declared another global health emergency due to the rapidly spreading monkeypox (Mpox) outbreak in numerous African countries. To address the unmet need to contain the outbreak using the existing vaccines, this study developed a lyophilization process for an effective, scalable and affordable Mpox mRNA-LNP vaccine candidate to address the global health crisis. A comprehensive evaluation and optimization of the vaccine formulation (the type/concentration of cryoprotectants, the type/concentration of buffer system, as well as the mRNA concentration and reconstitution solvent) and the freeze-drying process parameters (freezing method, temperature, cooling rate and primary/secondary drying conditions) were conducted.

A Quadrivalent mRNA Immunization Elicits Potent Immune Responses against Multiple Orthopoxviral Antigens and Neutralization of Monkeypox Virus in Rodent Models.

The global outbreak of the 2022 monkeypox virus infection of humans and the 2023 documentation of a more virulent monkeypox in the Democratic Republic of the Congo raised public health concerns about the threat of human-to-human transmission of zoonotic diseases. Currently available vaccines may not be sufficient to contain outbreaks of a more transmissible and pathogenic orthopoxvirus. Development of a safe, effective, and scalable vaccine against orthopoxviruses to stockpile for future emergencies is imminent.

Novel simian immunodeficiency virus CTL epitopes restricted by MHC class I molecule Mamu-B*01 are highly conserved for long term in DNA/MVA-vaccinated, SHIV-challenged rhesus macaques.

Simian immunodeficiency virus (SIV) infection of rhesus macaques provides an excellent model for investigating the basis of protective immunity against human immunodeficiency virus (HIV). One limitation of this model, however, has been the availability of a small number of known MHC class I-restricted CTL epitopes for investigating virus-specific immune responses. We assessed CTL responses against SIV Gag in a cohort of DNA/modified vaccinia virus Ankara (MVA)-vaccinated/simian-human immunodeficiency virus (SHIV)-challenged rhesus macaques.