Smokers are more likely to have been infected by cytomegalovirus than non-smokers, for socioeconomic reasons. Patients with cytomegalovirus reactivation, including the immunocompetent, consistently require increased duration of mechanical ventilation, prolonged hospitalization, and have worse survival. Studies like this are quackery and charlatanism because they ignore the role of infection, for ideological reasons.

http://www.smokershistory.com/CMVimmun.html