Effectiveness of a 23-valent polysaccharide vaccine in preventing pneumonia and non-invasive pneumococcal infection in elderly people: a large-scale retrospective cohort study.
This retrospective cohort study evaluated the effectiveness of a 23-valent pneumococcal polysaccharide vaccine in reducing hospital admission for pneumonia, otitis media and exacerbation of asthma or other syndromes due to Streptococcus pneumoniae in 9170 high-risk individuals. Cohort members were followed from 1 January 1998 to 31 December 2002. With regard to preventing hospitalization due to pneumonia, we observed a decrease in the incidence of 1/10000 person-months and a reduction in the relative risk of 38% in the vaccinated cohort compared with the non-vaccinated subjects. A decrease in the risk of hospital admission for asthma, acute otitis media, chronic obstructive pulmonary disease and other respiratory infections was also observed in vaccinated compared with non-vaccinated subjects. The specificity of these findings was confirmed by the lack of a protective effect from vaccination for those outcomes, such as hospitalization 'for all causes' and 'other otorhinolaryngological diagnoses', that were not directly related to pneumococcal disease.
Ansaldi
F
F
Department of Health Sciences, University of Genoa, Genoa, Italy.
Turello
V
V
Lai
P
P
Bastone
G
G
De Luca
S
S
Rosselli
R
R
Durando
P
P
Sticchi
L
L
Gasparini
R
R
Delfino
E
E
Icardi
G
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D015331:Cohort Studies; D005260:Female; D016330:Frail Elderly; D006801:Humans; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage*; D011018:Pneumonia, Pneumococcal / Q000188:drug therapy / Q000517:prevention & control*; D012141:Respiratory Tract Infections / Q000382:microbiology / Q000517:prevention & control; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D014611:Vaccination
C414006:23-valent pneumococcal capsular polysaccharide vaccine; D022242:Pneumococcal Vaccines