Epidemiology and Infection



Influenza A among community-dwelling elderly persons in Leicestershire during winter 1993–4; cigarette smoking as a risk factor and the efficacy of influenza vaccination


K. G. NICHOLSON a1c1, J. KENT a2 and V. HAMMERSLEY a2
a1 Infectious and Tropical Diseases Unit, Leicester Royal Infirmary, Leicester LE1 5WW, UK
a2 Leicester University School of Medicine, Department of Microbiology and Immunology, University Road, Leicester LE1 9HN, UK

Abstract

In a prospective study of community-dwelling people 60–90 years of age, we examined the coverage of influenza vaccine during 1992–3 and 1993–4, the efficacy of vaccination in reducing serologically-confirmed clinical episodes of influenza A during 1993, and the effect of cigarette smoking. During 1992 and 1993, influenza vaccine was given to 106/215 (49%) and 120/204 (59%) people with risk conditions, and 84/225 (37%) and 103/235 (44%) without risk conditions. Influenza vaccination and general practitioner consultations during 1992 were independent predictors of vaccination in 1993, but current smoking was a negative predictor. Of 209 unimmunized people, 8/35 (23%) smokers had clinical influenza as compared with 11/174 (6 %) non-smokers (OR 4·4, 95% CI 1·6 to 11·9). Of 371 non-smokers, 1/197 (0·5%) vaccinees had influenza as compared with 11/174 (6 %) non-vaccinees (OR 0·075, 95% CI 0·587 to 0·009). No cases of influenza occurred among 21 current smokers who were vaccinated.

(Accepted March 9 1999)


Correspondence:
c1 Author for correspondence.


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