Jandrasits, DamianDamianJandrasitsZüst, RolandRolandZüstSiegrist, DeniseDeniseSiegristEngler, Olivier BOlivier BEnglerWeber, BenjaminBenjaminWeberSchmidt, Kristina MKristina MSchmidtJonsdottir, Hulda RunHulda RunJonsdottir2024-10-262024-10-262024-05-30https://boris-portal.unibe.ch/handle/20.500.12422/177910Due 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.enELISA Imvamune/Imvanex/Jynneos Monkeypox virus Neutralizing antibodies Occupational biosafety Vaccines Vaccinia virus serum neutralization test600 - Technology::610 - Medicine & healtharticle10.48350/1975183882671210.1016/j.heliyon.2024.e31490