Smoking cessation and vaccination.

A significant proportion of COPD patients (∼40%) continue smoking despite knowing that they have the disease. Smokers with COPD exhibit higher levels of nicotine dependence, and have lower self-efficacy and self-esteem, which affects their ability to quit smoking. Treatment should be adapted to the needs of individual patients with different levels of tobacco dependence. The combination of counselling plus pharmacotherapy is the most effective cessation treatment for COPD. In patients with severe COPD, varenicline and bupropion have been shown to have the highest abstinence rates compared with nicotine replacement therapy. There is a lack of evidence to support that smoking cessation reduction or harm reduction strategies have benefits in COPD patients. The long-term efficacy and safety of electronic cigarettes for smoking cessation need to be evaluated in high-risk populations; therefore, it is not possible to recommend their use for smoking cessation in COPD. Future studies with the new generation of nicotine vaccines are necessary to determine their effectiveness in smokers in general and in COPD patients.

Clinical implications of nicotine as an antimicrobial agent and immune modulator.

Nicotine is perhaps the most important and potent, pharmacologically active substance in tobacco products. This commentary examines the possible effects that nicotine has on microbial viability and also on the host's immune system as it responds to the indigenous microflora (the microbiome) due to nicotine-induced changes to the indigenous microbial environment and any associated antigenic stimulation / immunization that may occur. To our knowledge, the analysis of such profound microbiologic changes attributable to a tobacco-related product, such as nicotine, has not been fully explored in the context of its consequences on the viability of the microbiome/microbiota and on some of the host's basic physiologic processes, such as the immune response, and its possible association on the induction and persistence of certain immunologically related diseases. Future studies should be aimed at uncovering the molecular mechanisms involved in such interactions, especially in the context of manipulating them for therapeutic purposes.