Zeolitic Imidazolate Frameworks Allows for the Thermal Stabilization of Live Viral Vaccine in the Absence of Lyophilization

The impact of vaccines extends beyond the improvement of individual health, significantly lowering the burden of infectious disease in healthcare systems and strengthening the societal infrastructure and economic stability of a nation. Unfortunately, the substantial benefits of vaccines are often disproportionately encountered in affluent nations, with the need for cold-chain logistics heavily contributing to this inequity. Here, we describe the biomimetic mineralization of a live viral vaccine using metal-organic frameworks (MOFs) to alleviate stress caused by ambient temperatures. Utilizing a zinc-based MOF (ZIF-8), we demonstrated the advantages of a higher concentration of the ZIF-8 precursor constituents for coverage of viral antigens and recovery of the live viral Newcastle Disease Virus (NDV) vaccine. Using a candidate MOF-based formulation, we identified that ZIF-8 can maintain effective coverage of NDV V4 virions following lyophilization; however, viral titer was negatively impacted if rapid freezing was integrated. As an alternative cost-effective storage technique, we utilized filter paper drying for long-term stabilization of various ZIF-8@NDV formulations. We demonstrated that the presence of ZIF-8 significantly contributed to vaccine stability when stored at 25 or 37 °C compared to NDV in solution. In summary, our findings highlight the potential of utilizing MOFs for stabilization of live viral vaccines at ambient temperatures and demonstrate the viability of filter paper as an alternative to lyophilization for vaccine preservation.