LIU WANG-DAKUAN-YIN LINLin, Chi-YingChi-YingLinTAI-LING CHAOKAI-HSIANG STANLEY CHENHSIN-YUN SUNHsu, Wei-TingWei-TingHsuYU-SHAN HUANGHuang, Chun-FuChun-FuHuangYU-CHUNG CHUANGLi, Guei-ChiGuei-ChiLiLiu, Wen-ChunWen-ChunLiuWu, Cheng-HsinCheng-HsinWuSu, Yi-ChingYi-ChingSuChang, Lan-HsinLan-HsinChangLin, Chia-YiChia-YiLinWu, Pei-YingPei-YingWuChen, Ling-YaLing-YaChenLuo, Yu-ZhenYu-ZhenLuoChang, Hsi-YenHsi-YenChangChen, Yi-ChunYi-ChunChenYao, YiYiYaoChen, Yi-TingYi-TingChenJANN-TAY WANGWANG-HUEI SHENGSZU-MIN HSIEHSHIH-CHUNG CHANGCHIEN-CHING HUNGSUI-YUAN CHANG2025-03-102025-03-102025-01-31https://scholars.lib.ntu.edu.tw/handle/123456789/725627Objectives: The data on immune responses of individuals undergoing modified vaccinia Ankara-Bavarian Nordic (MVA-BN) vaccination are scarce. We aimed to compare Mpox virus-specific antibody and neutralizing antibody responses among people with and those without HIV receiving MVA-BN vaccines. Methods: This prospective study enrolled participants undergoing two-dose MVA-BN vaccination to investigate seroresponses after vaccination. Blood samples were collected before and after each dose of vaccination for determinations of anti-A29 and anti-H3 IgG. Neutralization tests were conducted for samples tested positive for both anti-A29 and anti-H3 IgG. Results: Overall, 441 participants undergoing two-dose MVA-BN vaccination were enrolled. Seroconversion for anti-A29 and anti-H3 IgG, respectively, after the second dose of vaccination was 18.2% and 61.2%, 10.9% and 65.0%, and 51.6% and 90.6% among people with HIV, people without HIV, and those who had had smallpox vaccination previously, respectively. About 20% of the participants with seroconversion lost seroresponses after a 7-month period of observation. None of the serum samples from vaccinated participants demonstrated neutralizing ability. Conclusions: Participants with previous smallpox vaccination had higher and more sustained antibody responses after receiving two doses of MVA-BN vaccines than those who had not undergone smallpox vaccination. More studies are warranted to assess the seroresponses to booster MVA-BN vaccination for vaccine nonresponders or those having lost seroresponses.enAIDSHIVHumoral immunityImmunogenicityMonkeypoxSTI[SDGs]SDG3journal article10.1016/j.ijid.2025.10783039894441