Phase-out of smallpox vaccination and the female/male HIV-1 prevalence ratio: an ecological study from Guinea-Bissau

Andreas Rieckmann*, Marie Villumsen, Bo Langhoff Hønge, Signe Sørup, Amabelia Rodrigues, Zacarias Jose Da Silva, Hilton Whittle, Christine Benn, Peter Aaby

*Kontaktforfatter for dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

31 Downloads (Pure)

Resumé

Objective In Guinea-Bissau, West Africa, we observed that having a smallpox vaccination scar was associated with lower HIV-1 prevalence, more strongly for women than men. If this represents a causal effect, the female/male HIV-1 prevalence ratio would increase for birth cohorts no longer receiving smallpox vaccination due to the phase-out of this vaccine. Design An ecological design using HIV surveys and information about smallpox vaccination coverage. Setting Urban and rural Guinea-Bissau. Participants Participants in HIV surveys were grouped into an age group with decreasing smallpox vaccination coverage (15-34 years) and an age group with steady smallpox vaccination coverage (≥35 years). Interventions The exposure of interest was the phase-out of the smallpox vaccine in Guinea-Bissau. Primary and secondary outcome measures HIV-1 prevalence. Results At both sites, the female/male HIV-1 prevalence ratio increased by calendar time for the age group with decreasing smallpox vaccination coverage; the combined female/male HIV-1 prevalence ratio among people aged 15-34 years was 1.00 (95% CI 0.17 to 5.99) in 1987-1990, 1.16 (95% CI 0.69 to 1.93) in 1996-1997, 2.32 (95% CI 1.51 to 3.56) in 2006-2007 (p value for no trend=0.04). There was no increase in the female-to-male HIV-1 prevalence ratio for the age group >35 years with steady smallpox vaccination coverage; 1.93 (95% CI 0.40 to 9.25) in 1987-1990, 1.32 (95% CI 0.83 to 2.10) in 1996-1997, 0.81 (95% CI 0.56 to 1.16) in 2006-2007 (p value for no trend=0.07). Conclusions Thus, data was compatible with the deduction that the phase-out of smallpox vaccination may have increased the susceptibility to HIV-1 relatively more for women than men. Hence, phasing out smallpox vaccination may have contributed to the global increase in the female/male HIV-1 prevalence ratio among young individuals. Due to the potential fallacies of ecological studies, the results should be interpreted carefully, and this hypothesis needs further assessment. If the hypothesis is true, studies of smallpox vaccination could inform HIV-1 vaccine research.

OriginalsprogEngelsk
Artikelnummere031415
TidsskriftBMJ Open
Vol/bind9
Udgave nummer10
Antal sider7
ISSN2044-6055
DOI
StatusUdgivet - 1. okt. 2019

Fingeraftryk

Guinea-Bissau
Smallpox
HIV-1
Age Groups
Smallpox Vaccine
HIV
AIDS Vaccines
Western Africa
Needs Assessment

Citer dette

Rieckmann, Andreas ; Villumsen, Marie ; Hønge, Bo Langhoff ; Sørup, Signe ; Rodrigues, Amabelia ; Da Silva, Zacarias Jose ; Whittle, Hilton ; Benn, Christine ; Aaby, Peter. / Phase-out of smallpox vaccination and the female/male HIV-1 prevalence ratio : an ecological study from Guinea-Bissau. I: BMJ Open. 2019 ; Bind 9, Nr. 10.
@article{0c21fbde8d6a4a1bafbeca399185edfd,
title = "Phase-out of smallpox vaccination and the female/male HIV-1 prevalence ratio: an ecological study from Guinea-Bissau",
abstract = "Objective In Guinea-Bissau, West Africa, we observed that having a smallpox vaccination scar was associated with lower HIV-1 prevalence, more strongly for women than men. If this represents a causal effect, the female/male HIV-1 prevalence ratio would increase for birth cohorts no longer receiving smallpox vaccination due to the phase-out of this vaccine. Design An ecological design using HIV surveys and information about smallpox vaccination coverage. Setting Urban and rural Guinea-Bissau. Participants Participants in HIV surveys were grouped into an age group with decreasing smallpox vaccination coverage (15-34 years) and an age group with steady smallpox vaccination coverage (≥35 years). Interventions The exposure of interest was the phase-out of the smallpox vaccine in Guinea-Bissau. Primary and secondary outcome measures HIV-1 prevalence. Results At both sites, the female/male HIV-1 prevalence ratio increased by calendar time for the age group with decreasing smallpox vaccination coverage; the combined female/male HIV-1 prevalence ratio among people aged 15-34 years was 1.00 (95{\%} CI 0.17 to 5.99) in 1987-1990, 1.16 (95{\%} CI 0.69 to 1.93) in 1996-1997, 2.32 (95{\%} CI 1.51 to 3.56) in 2006-2007 (p value for no trend=0.04). There was no increase in the female-to-male HIV-1 prevalence ratio for the age group >35 years with steady smallpox vaccination coverage; 1.93 (95{\%} CI 0.40 to 9.25) in 1987-1990, 1.32 (95{\%} CI 0.83 to 2.10) in 1996-1997, 0.81 (95{\%} CI 0.56 to 1.16) in 2006-2007 (p value for no trend=0.07). Conclusions Thus, data was compatible with the deduction that the phase-out of smallpox vaccination may have increased the susceptibility to HIV-1 relatively more for women than men. Hence, phasing out smallpox vaccination may have contributed to the global increase in the female/male HIV-1 prevalence ratio among young individuals. Due to the potential fallacies of ecological studies, the results should be interpreted carefully, and this hypothesis needs further assessment. If the hypothesis is true, studies of smallpox vaccination could inform HIV-1 vaccine research.",
keywords = "heterologous immunity, HIV-1, non-specific effects of vaccines, smallpox vaccination, Vaccinia",
author = "Andreas Rieckmann and Marie Villumsen and H{\o}nge, {Bo Langhoff} and Signe S{\o}rup and Amabelia Rodrigues and {Da Silva}, {Zacarias Jose} and Hilton Whittle and Christine Benn and Peter Aaby",
year = "2019",
month = "10",
day = "1",
doi = "10.1136/bmjopen-2019-031415",
language = "English",
volume = "9",
journal = "B M J Open",
issn = "2044-6055",
publisher = "BMJ Group",
number = "10",

}

Phase-out of smallpox vaccination and the female/male HIV-1 prevalence ratio : an ecological study from Guinea-Bissau. / Rieckmann, Andreas; Villumsen, Marie; Hønge, Bo Langhoff; Sørup, Signe; Rodrigues, Amabelia; Da Silva, Zacarias Jose; Whittle, Hilton; Benn, Christine; Aaby, Peter.

I: BMJ Open, Bind 9, Nr. 10, e031415, 01.10.2019.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Phase-out of smallpox vaccination and the female/male HIV-1 prevalence ratio

T2 - an ecological study from Guinea-Bissau

AU - Rieckmann, Andreas

AU - Villumsen, Marie

AU - Hønge, Bo Langhoff

AU - Sørup, Signe

AU - Rodrigues, Amabelia

AU - Da Silva, Zacarias Jose

AU - Whittle, Hilton

AU - Benn, Christine

AU - Aaby, Peter

PY - 2019/10/1

Y1 - 2019/10/1

N2 - Objective In Guinea-Bissau, West Africa, we observed that having a smallpox vaccination scar was associated with lower HIV-1 prevalence, more strongly for women than men. If this represents a causal effect, the female/male HIV-1 prevalence ratio would increase for birth cohorts no longer receiving smallpox vaccination due to the phase-out of this vaccine. Design An ecological design using HIV surveys and information about smallpox vaccination coverage. Setting Urban and rural Guinea-Bissau. Participants Participants in HIV surveys were grouped into an age group with decreasing smallpox vaccination coverage (15-34 years) and an age group with steady smallpox vaccination coverage (≥35 years). Interventions The exposure of interest was the phase-out of the smallpox vaccine in Guinea-Bissau. Primary and secondary outcome measures HIV-1 prevalence. Results At both sites, the female/male HIV-1 prevalence ratio increased by calendar time for the age group with decreasing smallpox vaccination coverage; the combined female/male HIV-1 prevalence ratio among people aged 15-34 years was 1.00 (95% CI 0.17 to 5.99) in 1987-1990, 1.16 (95% CI 0.69 to 1.93) in 1996-1997, 2.32 (95% CI 1.51 to 3.56) in 2006-2007 (p value for no trend=0.04). There was no increase in the female-to-male HIV-1 prevalence ratio for the age group >35 years with steady smallpox vaccination coverage; 1.93 (95% CI 0.40 to 9.25) in 1987-1990, 1.32 (95% CI 0.83 to 2.10) in 1996-1997, 0.81 (95% CI 0.56 to 1.16) in 2006-2007 (p value for no trend=0.07). Conclusions Thus, data was compatible with the deduction that the phase-out of smallpox vaccination may have increased the susceptibility to HIV-1 relatively more for women than men. Hence, phasing out smallpox vaccination may have contributed to the global increase in the female/male HIV-1 prevalence ratio among young individuals. Due to the potential fallacies of ecological studies, the results should be interpreted carefully, and this hypothesis needs further assessment. If the hypothesis is true, studies of smallpox vaccination could inform HIV-1 vaccine research.

AB - Objective In Guinea-Bissau, West Africa, we observed that having a smallpox vaccination scar was associated with lower HIV-1 prevalence, more strongly for women than men. If this represents a causal effect, the female/male HIV-1 prevalence ratio would increase for birth cohorts no longer receiving smallpox vaccination due to the phase-out of this vaccine. Design An ecological design using HIV surveys and information about smallpox vaccination coverage. Setting Urban and rural Guinea-Bissau. Participants Participants in HIV surveys were grouped into an age group with decreasing smallpox vaccination coverage (15-34 years) and an age group with steady smallpox vaccination coverage (≥35 years). Interventions The exposure of interest was the phase-out of the smallpox vaccine in Guinea-Bissau. Primary and secondary outcome measures HIV-1 prevalence. Results At both sites, the female/male HIV-1 prevalence ratio increased by calendar time for the age group with decreasing smallpox vaccination coverage; the combined female/male HIV-1 prevalence ratio among people aged 15-34 years was 1.00 (95% CI 0.17 to 5.99) in 1987-1990, 1.16 (95% CI 0.69 to 1.93) in 1996-1997, 2.32 (95% CI 1.51 to 3.56) in 2006-2007 (p value for no trend=0.04). There was no increase in the female-to-male HIV-1 prevalence ratio for the age group >35 years with steady smallpox vaccination coverage; 1.93 (95% CI 0.40 to 9.25) in 1987-1990, 1.32 (95% CI 0.83 to 2.10) in 1996-1997, 0.81 (95% CI 0.56 to 1.16) in 2006-2007 (p value for no trend=0.07). Conclusions Thus, data was compatible with the deduction that the phase-out of smallpox vaccination may have increased the susceptibility to HIV-1 relatively more for women than men. Hence, phasing out smallpox vaccination may have contributed to the global increase in the female/male HIV-1 prevalence ratio among young individuals. Due to the potential fallacies of ecological studies, the results should be interpreted carefully, and this hypothesis needs further assessment. If the hypothesis is true, studies of smallpox vaccination could inform HIV-1 vaccine research.

KW - heterologous immunity

KW - HIV-1

KW - non-specific effects of vaccines

KW - smallpox vaccination

KW - Vaccinia

U2 - 10.1136/bmjopen-2019-031415

DO - 10.1136/bmjopen-2019-031415

M3 - Journal article

C2 - 31666269

AN - SCOPUS:85074354211

VL - 9

JO - B M J Open

JF - B M J Open

SN - 2044-6055

IS - 10

M1 - e031415

ER -