Evidence of Smallpox and Monkeypox Antibodies in Human Immunoglobulin Preparations: Implications for Post-Exposure Prophylaxis

The resurgence of mpox, particularly in regions where the virus was previously non-endemic, has reignited interest in the cross-protective potential of smallpox antibodies. Given the genetic similarity between the mpox virus and variola virus (the causative agent of smallpox), antibodies generated against smallpox may offer a degree of protection against mpox. This study investigates the presence of smallpox and mpox antibodies in human immunoglobulin preparations containing IgG against both mpox virus and vaccinia virus using ELISA techniques. The implications of these findings for post-exposure prophylaxis (PEP) are discussed in light of the recent mpox outbreaks in Africa, as reported by the World Health Organization (WHO). Current data suggest that smallpox vaccination, even decades after eradication, may confer substantial protection against mpox, thereby serving as a critical tool in managing emerging outbreaks. Further the presence of mpox antibodies in immunoglobulin preparations was also significant. These findings strongly suggest the potential use of intravenous immunoglobulins preparation as possible therapeutic strategy. Particularly it also underscores the need for further research into the development of targeted post-exposure prophylaxis strategies that leverage the cross-reactivity of orthopoxvirus antibodies.