Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil.
ECOVIR-Research Group on the Ecology of Emerging Viruses-UFMG/CNPq, Belo Horizonte, Minas Gerais, Brazil.
J Med Virol. 2023 Jun;95(6):e28859. doi: 10.1002/jmv.28859.
Since 1999, Vaccinia virus (VACV) has been described as a causative agent of bovine vaccinia (BV), a zoonotic disease that occurs mainly in rural areas of Brazil. However, the circulation of VACV in urban environments and its associated burden has been poorly explored. Moreover, the current monkeypox (mpox) outbreak has raised questions regarding the immune status of the worldwide population previous vaccinated against smallpox. Hence, we conducted a cross-sectional study to better understand the prevalence of anti-OPV neutralizing antibodies (NA) and related exposure factors in a susceptible urban population of Brazil. A total of 372 individuals were sampled, yielding an overall seroprevalence of 16.9% (CI95% = 13.4-21.1), and antibodies titers ranging from 100 to 800 neutralizing units/mL. The prevalence of NA among individuals potentially vaccinated against smallpox (≥36 years old [yo]) was 24.9% (IC 95% = 19.5-31.2), and among those unvaccinated (<36yo) was 6.7% (IC 95% = 3.7-11.8). Interestingly, contact with horses was pointed out as an exposure factor for the presence of NA, however, the multivariate logistic regression analysis indicated that age ≥36yo and the presence of vaccine take were independently associated with the presence of anti-OPV NA. Our findings suggest that vulnerable populations could be subclinically exposed to VACV in urban areas, drawing attention to alternative routes of zoonotic VACV exposure. Our data is also important for better strategies to mitigate zoonotic OPV infections mainly among vulnerable populations.
自 1999 年以来，牛痘病毒（VACV）被描述为一种引起牛痘（BV）的病原体，这是一种主要发生在巴西农村地区的人畜共患病。然而，VACV 在城市环境中的传播及其相关负担尚未得到充分探索。此外，当前的猴痘（mpox）疫情引发了人们对全球以前接种过天花疫苗的人群免疫状况的质疑。因此，我们进行了一项横断面研究，以更好地了解巴西易感城市人群中抗 OPV 中和抗体（NA）的流行情况和相关的暴露因素。共采集了 372 个人的样本，总血清阳性率为 16.9%（95%CI95%=13.4-21.1），抗体滴度范围为 100 至 800 中和单位/ml。有潜在天花疫苗接种史（≥36 岁）的个体中 NA 的流行率为 24.9%（95%CI95%=19.5-31.2），无接种史（<36 岁）的个体中 NA 的流行率为 6.7%（95%CI95%=3.7-11.8）。有趣的是，与马接触被指出是存在 NA 的暴露因素，但多变量逻辑回归分析表明，年龄≥36 岁和存在疫苗接种是与存在抗 OPV NA 相关的独立因素。我们的研究结果表明，在城市地区，易感人群可能会受到 VACV 的亚临床暴露，这引起了人们对人畜共患 VACV 暴露的替代途径的关注。我们的数据对于制定更好的策略来减轻主要在弱势群体中的人畜共患 OPV 感染也很重要。
