The effect of smoking on influenza, influenza vaccination efficacy and on the antibody response to influenza vaccination.

"Vaccination of smokers against influenza was serologically more efficacious compared to non-smokers in our study (see ). As this was not expected and no other studies investigated the efficacy of influenza vaccination in smokers and non-smokers, we sought support for this finding in the antibody response after vaccination. A greater titre rise due to vaccination was observed in smokers compared to non-smokers for two out of four strains 3 weeks after vaccination. A greater antibody response was also found by Finklea et al.. In their study pre-vaccination titres (that were lower for smokers than non-smokers) leveled up after vaccination. A possible explanation is that smokers develop a better immunological protection after vaccination, resulting in a lower incidence of serological influenza compared to non-smokers. The clinical relevance of this finding appears to be low, because no difference in efficacy of vaccination was found for clinical influenza between smokers and non-smokers in our study. Also, MacKenzie et al. and Knowles et al. found no greater antibody response in smokers compared to non-smokers after vaccination with influenza vaccine, . Instead, hepatitis B vaccination has been shown to be less immunogenic in smokers versus non-smokers in several studies, , . For example, for subjects receiving hepatitis B vaccine at 0, 1 and 6 months (standard schedule) it was found that vaccinated smokers had lower antibody levels than non-smokers after 3, 7 and 13 months. In summary, the tendency for smokers to have a higher antibody response than non-smokers found in our study is not found in other studies on influenza vaccination (except Finklea et al.) and hepatitis B vaccination. The greater protection against serological influenza in smokers compared to non-smokers found in our study is therefore hardly supported by other immunological data."