S W Michelsen1, B Soborg1, A Koch1, L Carstensen1, S T Hoff2, E M Agger2, T Lillebaek3, H C F Sorensen4, J Wohlfahrt1, M Melbye1. 1. Department of Epidemiology Research, Statens Serum Institut, Copenhagen S, Denmark. 2. Department of Infectious Disease Immunology, Statens Serum Institut, Copenhagen S, Denmark. 3. International Reference Laboratory of Mycobacteriology, Statens Serum Institut, Copenhagen S, Denmark. 4. The Tasiilaq District Hospital, Tasiilaq, Greenland.
Abstract
BACKGROUND: The BCG vaccine's ability to prevent Mycobacterium tuberculosis infection (MTI) remains highly debated. In Greenland, BCG vaccination was introduced in 1955, but was temporarily discontinued (1991-1996) due to nationwide policy changes. The study aimed to use the transient stop in BCG vaccination to evaluate the effect of vaccination on MTI prevalence and TB incidence. METHODS: MTI study: A cross-sectional study (2012), comprising East Greenlanders born during 1982-2006, evaluated the effect of BCG vaccination on MTI prevalence; a positive interferon γ release assay defined an MTI case. Associations were estimated using logistic regression. TB study: a cohort study covering the same birth cohorts with follow-up until 2012 evaluated the vaccine's effect on TB incidence. A personal identifier allowed for follow-up in the TB notification system. Associations were estimated using Cox regression. RESULTS: MTI study: Included 953 participants; 81% were BCG-vaccinated; 29% had MTI, 23% among vaccinated and 57% among non-vaccinated. BCG vaccination reduced the odds of MTI, OR 0.52 (95% CI 0.32 to 0.85), p=0.01. Vaccine effectiveness against MTI was 20%. TB study: Included 1697 participants followed for 21,148 person-years. 6% were notified with TB, 4% among vaccinated and 11% among non-vaccinated. BCG vaccination reduced the risk of TB, HR 0.50 (95% CI 0.26 to 0.95), p=0.03, yielding a vaccine effectiveness of 50%. CONCLUSIONS: BCG vaccination was effective in reducing both MTI and TB disease among children and young adults in a TB high-endemic setting in Greenland. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
BACKGROUND: The BCG vaccine's ability to prevent Mycobacterium tuberculosis infection (MTI) remains highly debated. In Greenland, BCG vaccination was introduced in 1955, but was temporarily discontinued (1991-1996) due to nationwide policy changes. The study aimed to use the transient stop in BCG vaccination to evaluate the effect of vaccination on MTI prevalence and TB incidence. METHODS: MTI study: A cross-sectional study (2012), comprising East Greenlanders born during 1982-2006, evaluated the effect of BCG vaccination on MTI prevalence; a positive interferon γ release assay defined an MTI case. Associations were estimated using logistic regression. TB study: a cohort study covering the same birth cohorts with follow-up until 2012 evaluated the vaccine's effect on TB incidence. A personal identifier allowed for follow-up in the TB notification system. Associations were estimated using Cox regression. RESULTS: MTI study: Included 953 participants; 81% were BCG-vaccinated; 29% had MTI, 23% among vaccinated and 57% among non-vaccinated. BCG vaccination reduced the odds of MTI, OR 0.52 (95% CI 0.32 to 0.85), p=0.01. Vaccine effectiveness against MTI was 20%. TB study: Included 1697 participants followed for 21,148 person-years. 6% were notified with TB, 4% among vaccinated and 11% among non-vaccinated. BCG vaccination reduced the risk of TB, HR 0.50 (95% CI 0.26 to 0.95), p=0.03, yielding a vaccine effectiveness of 50%. CONCLUSIONS: BCG vaccination was effective in reducing both MTI and TB disease among children and young adults in a TB high-endemic setting in Greenland. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Authors: Thomas R Hawn; Tracey A Day; Thomas J Scriba; Mark Hatherill; Willem A Hanekom; Thomas G Evans; Gavin J Churchyard; James G Kublin; Linda-Gail Bekker; Steven G Self Journal: Microbiol Mol Biol Rev Date: 2014-12 Impact factor: 11.056
Authors: Karen Bjorn-Mortensen; Karin Ladefoged; Jacob Simonsen; Sascha W Michelsen; Hans Christian F Sørensen; Anders Koch; Troels Lillebaek; Aase Bengaard Andersen; Bolette Soborg Journal: Int J Circumpolar Health Date: 2016-10-25 Impact factor: 1.228
Authors: Anne Christine Nordholm; Bolette Søborg; Mikael Andersson; Steen Hoffmann; Peter Skinhøj; Anders Koch Journal: PLoS One Date: 2017-02-03 Impact factor: 3.240
Authors: K Bjorn-Mortensen; B Soborg; A Koch; K Ladefoged; M Merker; T Lillebaek; A B Andersen; S Niemann; T A Kohl Journal: Sci Rep Date: 2016-09-12 Impact factor: 4.379