Does smallpox vaccination modify HIV disease progression among ART-naive people living with HIV in Africa?

Abstract

SUMMARYWe examined the association between a history of smallpox vaccination and immune activation (IA) in a population of antiretroviral therapy-naïve people living with HIV (PLHIV). A cross-sectional study was conducted in Senegal from July 2015 to March 2017. Smallpox vaccination was ascertained by the presence of smallpox vaccine scar and IA by the plasma level ofβ-2-microglobulin (β2m). The association was analysed using logistic regression and linear regression models. The study population comprised 101 PLHIV born before 1980 with a median age of 47 years (interquartile range (IQR) = 42–55); 57·4% were women. Smallpox vaccine scar was present in 65·3% and the medianβ2m level was 2·59 mg/l (IQR = 2·06–3·86). After adjustment, the presence of smallpox vaccine scar was not associated with aβ2m level ⩾2·59 mg/l (adjusted odds ratio 0·94; 95% confidence interval 0·32–2·77). This result was confirmed by the linear regression model. Our study does not find any association between the presence of smallpox vaccine scar and theβ2m level and does not support any association between a previous smallpox vaccination and HIV disease progression. In this study, IA is not a significant determinant of the reported non-targeted effect of smallpox vaccination in PLHIV.