The Effect of Smallpox and Bacillus Calmette-Guérin Vaccination on the Risk of Human Immunodeficiency Virus-1 Infection in Guinea-Bissau and Denmark

TY - JOUR

T1 - The Effect of Smallpox and Bacillus Calmette-Guérin Vaccination on the Risk of Human Immunodeficiency Virus-1 Infection in Guinea-Bissau and Denmark

AU - Rieckmann, Andreas

AU - Villumsen, Marie

AU - Jensen, Mette Lundsby

AU - Ravn, Henrik

AU - da Silva, Zacarias J

AU - Sørup, Signe

AU - Baker, Jennifer Lyn

AU - Rodrigues, Amabélia

AU - Benn, Christine Stabell

AU - Roth, Adam E

AU - Aaby, Peter

PY - 2017/6/1

Y1 - 2017/6/1

N2 - BACKGROUND: The live smallpox and Bacillus Calmette-Guérin (BCG) vaccinations have been associated with better adult survival in both Guinea-Bissau and Denmark. In Guinea-Bissau, human immunodeficiency virus (HIV)-1 became an important cause of death after smallpox vaccination was phased out globally in 1980. We hypothesised that smallpox and BCG vaccinations were associated with a lower prevalence of HIV-1 infection, and we tested this hypothesis in both Guinea-Bissau and Denmark.METHODS: We conducted 2 studies: (1) a cross-sectional study of HIV infection and vaccination scars in Guinea-Bissau including 1751 individuals and (2) a case-base study with a background population of 46239 individuals in Denmark. In Guinea-Bissau, HIV-1 transmission was almost exclusively sexually transmitted. In Denmark, we excluded intravenous drug users. Data were analyzed using logistic regression.RESULTS: Bacillus Calmette-Guérin and/or smallpox vaccination compared with neither of these vaccines was associated with an adjusted odds ratio (aOR) for HIV-1 of 0.62 (95% confidence interval [CI], 0.36-1.07) in Guinea-Bissau and 0.70 (95% CI, 0.43-1.15) in Denmark. We combined the results from both settings in a meta-analysis (aOR = 0.66; 95% CI, 0.46-0.96). Data from Guinea-Bissau indicated a stronger effect of multiple smallpox vaccination scars (aOR = 0.27; 95% CI, 0.10-0.75) as follows: women, aOR = 0.18 (95% CI, 0.05-0.64); men, aOR = 0.52 (95% CI, 0.12-2.33); sex-differential effect, P = .29.CONCLUSIONS: The studies from Guinea-Bissau and Denmark, 2 very different settings, both suggest that the BCG and smallpox vaccines could be associated with a decreased risk of sexually transmitted HIV-1. It might be informative to pursue this observation and explore possible protective mechanisms as part of the search for an HIV-1 vaccine.

AB - BACKGROUND: The live smallpox and Bacillus Calmette-Guérin (BCG) vaccinations have been associated with better adult survival in both Guinea-Bissau and Denmark. In Guinea-Bissau, human immunodeficiency virus (HIV)-1 became an important cause of death after smallpox vaccination was phased out globally in 1980. We hypothesised that smallpox and BCG vaccinations were associated with a lower prevalence of HIV-1 infection, and we tested this hypothesis in both Guinea-Bissau and Denmark.METHODS: We conducted 2 studies: (1) a cross-sectional study of HIV infection and vaccination scars in Guinea-Bissau including 1751 individuals and (2) a case-base study with a background population of 46239 individuals in Denmark. In Guinea-Bissau, HIV-1 transmission was almost exclusively sexually transmitted. In Denmark, we excluded intravenous drug users. Data were analyzed using logistic regression.RESULTS: Bacillus Calmette-Guérin and/or smallpox vaccination compared with neither of these vaccines was associated with an adjusted odds ratio (aOR) for HIV-1 of 0.62 (95% confidence interval [CI], 0.36-1.07) in Guinea-Bissau and 0.70 (95% CI, 0.43-1.15) in Denmark. We combined the results from both settings in a meta-analysis (aOR = 0.66; 95% CI, 0.46-0.96). Data from Guinea-Bissau indicated a stronger effect of multiple smallpox vaccination scars (aOR = 0.27; 95% CI, 0.10-0.75) as follows: women, aOR = 0.18 (95% CI, 0.05-0.64); men, aOR = 0.52 (95% CI, 0.12-2.33); sex-differential effect, P = .29.CONCLUSIONS: The studies from Guinea-Bissau and Denmark, 2 very different settings, both suggest that the BCG and smallpox vaccines could be associated with a decreased risk of sexually transmitted HIV-1. It might be informative to pursue this observation and explore possible protective mechanisms as part of the search for an HIV-1 vaccine.

KW - Journal Article

U2 - 10.1093/ofid/ofx130

DO - 10.1093/ofid/ofx130

M3 - Journal article

C2 - 28852677

SN - 2328-8957

VL - 4

JO - Open Forum Infectious Diseases

JF - Open Forum Infectious Diseases

IS - 3

M1 - ofx130

ER -