Cross-reactive antibodies against monkeypox virus exist in the population immunized with vaccinia Tian Tan strain in China

• Published in: Infection, genetics and evolution genetics and evolution, 2023-09, Vol.113, p.105477, Article 105477
• Main Authors: Zhen, Zida, Zhang, Linlin, Li, Qi, Zhu, Yun, Wang, Xiaohuan, Fu, Xiaoyan, Ai, Junhong, Wang, Ran, Xie, Zhengde, Ma, Shuxuan
• Format: Article
• Language: English
• Subjects: Antibodies; Cross-reactive antibodies; evolution; family; genomics; genus; Humans; infection; Monkeypox virus; Monkeypox virus - genetics; Mpox (monkeypox); Seroepidemiologic Studies; Seroprevalence; vaccination; Vaccinia - epidemiology; Vaccinia Tian Tan strain; Vaccinia virus - genetics
• ISSN: 1567-1348; 1567-7257; 1567-7257
• DOI: 10.1016/j.meegid.2023.105477

Monkeypox virus (MPXV) belongs to the Orthopoxvirus genus. The worldwide outbreak of MPXV in 2022 has caused widespread concerns. Cross-reactive antibodies induced by vaccinia-inoculation can provide protection against reinfection by MPXV. The vaccinia Tian Tan (VTT) strain, which was widely inoculated in the Chinese population before the 1980s, has genomic differences from other vaccinia strains, although they all belong to the orthopoxviruses family. The current seroprevalence of VTT-vaccinated populations remains unclear more than four decades after the termination of vaccination campaigns in China. Our results showed that cross-reactive IgG antibodies against MPXV were present in 31.8% (75/236) of vaccinees four decades after VTT-vaccination, suggesting that vaccination with VTT may provide long-term protection against MPXV infection in some individuals. •Our findings provide the first domestic data on the prevalence of positive MPXV antibodies in a population four decades after VTT vaccination in China.•Although the antibody positivity in VTT vaccinees has decreased after four decades years, 31.5% of VTT vaccine recipients still had MPXV cross-reactive antibodies.•The determination of cross-reactive antibodies in serum will provide important data for the assessment of herd immunity against MPXV among such populations.