The etiology of chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (ME) is unknown.
In Norway, a vaccine against Neisseria meningitides group B was administered to teenagers in 1988-1989 in a protection trial. [Note: this bacterium may cause outbreaks of meningitis - inflammation of the membranes surrounding the spinal cord and brain - particularly in dormitory settings.]
In order to estimate the relative risk of CFS/ME according to vaccine history, we conducted a case-control study in 2007, with 201 cases diagnosed at one of two hospitals and 389 controls.
The adjusted odds ratio for CFS/ME was 1.06 (95% CI: 0.67-1.66) for subjects who received the active vaccine contrasted to subjects who did not. [Note: An odds ratio of 1.0 would mean exactly equal likelihood between two groups.]
Using this design, no statistically significant association between vaccination against meningococcal disease in teenagers and occurrence of CFS/ME could be observed.
Source: Vaccine, Nov 1, 2008.[E-pub ahead of print] PMID: 18984023, by Magnus P, Brubakk O, Nyland H, Wold BH, Gjessing HK, Brandt I, Eidem T, Nøkleby H, Stene-Larsen G. Norwegian Institute of Public Health, Oslo, Norway.