GEOGRAPHIC VARIATIONS IN INVASIVE PNEUMOCOCCAL DISEASE AND PNEUMOCOCCAL VACCINATION IN WESTERN EUROPE

D.Fedson.

Pasteur-Merieux-MSD.

M.D. David Fedson. 8 rue Jonas Salk. 69367 Lyon Cedex 07. France.

7E-Mail: fedson@fr.vaxiline.com

Background: Pneumococcal vaccine has not been widely used in western European countries, perhaps because of uncertainty about the incidence of pneumococcal pneumonia and limited evidence that vaccination prevents pneumococcal pneumonia in older adults. Recent increases in vaccine use in several countries have been accompanied by more information on the incidence of invasive pneumococcal disease and wider acceptance of retrospective studies showing that vaccination prevents invasive disease. Nonetheless, there are still large geographic variations among western European countries in the reported incidence of invasive disease and the use of the vaccine.

Methods: The aims of this study were to review data on the reported incidence of invasive pneumococcal disease and pneumococcal vaccine use in western European countries in the 1990s. Information on disease incidence was obtained from published and unpublished reports. Data were also gathered on disease incidence in smaller geographic regions within three countries. Information was also obtained on the cumulative use of pneumococcal vaccine in each country during the 5-year period 1993-1997. Vaccine use was also documented for smaller regions in two countries. Information on vaccination recommendations and reimbursement in 1997 was also obtained.

Findings: The reported incidence of invasive pneumococcal disease in western European countries varied from 6 to 27 cases per 100,000 persons of all ages and from 27 to 80 cases per 100,000 persons >65 years in age. In some countries the disease incidence appeared to have increased over the years. Larger (4- to 6-fold) variations in disease incidence were reported among smaller regions within three countries in individual years. During the 1993-1997 period, very large differences in pneumococcal vaccine use were observed between western European countries, between smaller regions within countries and between individual general practices. Although increased vaccine use was noted in several countries during this period, in 1997 pneumococcal vaccine remained little used throughout most of western Europe.

Interpretation: Geographic variations in the reported incidence of invasive pneumococcal disease between and within western European countries probably reflect differences in surveillance and case ascertainment, rather than true differences or absolute increases in disease occurrence. In all countries, the annual incidence is probably >15-20 cases per 100,000 persons of all ages, and >50 cases per 100,000 persons >65 years in age. The large differences in vaccine use observed between and within countries demonstrate that implementation of pneumococcal vaccination throughout western Europe remains uneven. Understanding the reasons underlying the geographic variations in the incidence of invasive pneumococcal disease and the use of pneumococcal vaccine will help to ensure that increasing numbers of people benefit from this safe and effective vaccine.