Vaccine

A vaccine is a biological preparation that provides active acquired immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins. The agent stimulates the body's immune system to recognize the agent as a threat, destroy it, and to further recognize and destroy any of the microorganisms associated with that agent that it may encounter in the future. Vaccines can be prophylactic (example: to prevent or ameliorate the effects of a future infection by a natural or "wild" pathogen), or therapeutic (e.g., vaccines against cancer are being investigated).

Should ME/CFS patients get a flu vaccine?
The general guidance is relying on your past experience with the vaccine and your known allergies.
 * 2014, FLU Vaccination and Chronic Fatigue Syndrome


 * 2017, The Flu and M.E. – all you need to know about the 2017/18 flu vaccine

Risk in developing ME/CFS
Some have reported developing ME/CFS after receiving vaccines for foreign travel. Whether causal or individuals already having a tendency to develop ME/CFS is more sensitive to vaccines than the general population is unknown. A studied concluded there is no evidence that the human papillomavirus vaccine will lead to developing chronic fatigue syndrome.

In one case of a 43-year-old man who developed CFS after having five vaccinations, previously with no previous ill health, it was "proposed that the cause of the CFS in this individual was a heightened immune response, initially to the aluminium in each of the adjuvants and thereafter spreading to other significant body stores of aluminium."

Risk in developing Gulf War Illness
Vaccinations have been proposed as an etiological factor in Gulf War Illness, especially the mass vaccinations given prior to military deployment.

Vaccination in the presence of elevated cortisol levels can drive cytokine expression toward TH2 dominance.