The Effects of Influenza Vaccination on Immune Function in Patients with Chronic Fatigue Syndrome/Myalgic Encephalomyelitis

Immune dysfunction is a hallmark of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME). The purpose of this pilot study was to identify the effects of influenza vaccination on immune function in patients with CFS/ME. We included 7 patients meeting the Centre for Disease Control and Prevention criteria (CDC 1994) for ME/CFS and 8 control subjects. Bloods were collected from all participants prior to vaccination with Influvac, a trivalent inactivated influenza vaccine (TIV), 14 and 28 days following vaccination. While vaccination may protect CFS/ME patients against influenza, it has the ability to increase cytotoxic activity and pro-inflammatory reactions post vaccination. The role of Tregs in promoting a toxic effect at 28 days post-vaccination in our patient group cannot be ruled out. The benefits of influenza vaccine still likely outweigh the risks CFS/ME patients experience following vaccination.