Third-generation smallpox vaccines induce low-level cross-protecting neutralizing antibodies against Monkeypox virus in laboratory workers
Damian Jandrasits,
Roland Züst,
Denise Siegrist,
Olivier B. Engler,
Benjamin Weber,
Kristina M. Schmidt,
Hulda R. Jonsdottir
Affiliations
Damian Jandrasits
Spiez Laboratory, Federal Office for Civil Protection, Spiez, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland; Institute of Microbiology, Department for Environment Constructions and Design, University of Applied Sciences and Arts of Southern Switzerland (SUPSI), 6850, Mendrisio, Switzerland
Roland Züst
Spiez Laboratory, Federal Office for Civil Protection, Spiez, Switzerland
Denise Siegrist
Spiez Laboratory, Federal Office for Civil Protection, Spiez, Switzerland
Olivier B. Engler
Spiez Laboratory, Federal Office for Civil Protection, Spiez, Switzerland
Benjamin Weber
Spiez Laboratory, Federal Office for Civil Protection, Spiez, Switzerland
Kristina M. Schmidt
Spiez Laboratory, Federal Office for Civil Protection, Spiez, Switzerland
Hulda R. Jonsdottir
Spiez Laboratory, Federal Office for Civil Protection, Spiez, Switzerland; Department of Rheumatology and Immunology, Inselspital University Hospital, Bern, Switzerland; Department of BioMedical Research, University of Bern, Bern, Switzerland; Corresponding author. Spiez Laboratory, Federal Office for Civil Protection, Spiez, Switzerland.
Due to the discontinuation of routine smallpox vaccination after its eradication in 1980, a large part of the human population remains naïve against smallpox and other members of the orthopoxvirus genus. As a part of biosafety personnel protection programs, laboratory workers receive prophylactic vaccinations against diverse infectious agents, including smallpox. Here, we studied the levels of cross-protecting neutralizing antibodies as well as total IgG induced by either first- or third-generation smallpox vaccines against Monkeypox virus, using a clinical isolate from the 2022 outbreak. Serum neutralization tests indicated better overall neutralization capacity after vaccination with first-generation smallpox vaccines, compared to an attenuated third-generation vaccine. Results obtained from total IgG ELISA, however, did not show higher induction of orthopoxvirus-specific IgGs in first-generation vaccine recipients. Taken together, our results indicate a lower level of cross-protecting neutralizing antibodies against Monkeypox virus in recipients of third-generation smallpox vaccine compared to first-generation vaccine recipients, although total IgG levels were comparable.
