Risk of lymphoma and leukaemia after bacille Calmette-Guerin and smallpox vaccination: A Danish case-cohort study

• Vaccines may have non-specific effects as suggested mainly in mortality studies from low-income countries. The objective was to examine the effects of BCG and smallpox vaccinations on subsequent risk of lymphoma and leukaemia in a Danish population experiencing rapid out-phasing of these vaccines. In a background cohort (N=47,622) from the Copenhagen School Health Records Register, cases of leukaemia (N=20) and lymphoma (N=51) were identified through the Danish Cancer Registry. The vaccination status of the cases was compared with the vaccination status of a 5% random sample (N = 2073) of the background cohort and analysed in a case-cohort design. BCG vaccination reduced the risk of lymphomas (HR=0.49 (95% CI: 0.26-0.93)), whereas smallpox vaccination did not (HR=1.32 (0.56-3.08)). With the small number of leukaemia cases, the analysis of leukaemia had limited power (BCG vaccination HR=0.81(0.31-2.16); smallpox vaccination HR=1.32 (0.49-3.53)). The present study with very reliable vaccine history information indicates a beneficial effect of BCG vaccination on the risk of lymphomas. (C) 2009 Elsevier Ltd. All rights reserved.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Mikrobiologi inom det medicinska området (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Microbiology in the medical area (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

Keyword

Haematologic malignancies

BCG vaccination

Smallpox vaccination

Publication and Content Type

art (subject category)

ref (subject category)