Evaluation of a mass influenza vaccination campaign.
Kawaura, a rural town in Kumamoto Prefecture, Japan, population approximately 6,800, started a mass influenza vaccination campaign in the 1999-2000 season for all residents > or = 3 years of age. The town provided free vaccinations to children < or = 13 years and the elderly > or = 65 years. Only 900 yen (US$8.80) was charged to the other residents for two vaccinations. In the 1999-2000 season, a total of 5,563 doses of vaccine were administered to 2,952 residents. Over 90% of the vaccinees received two doses. The program resulted in a vaccination rate of 43% of all residents. The vaccination rates for females and males were 40.7% and 36.8%, and for those of 3-14 years, 15-64 years, and > or = 65 years population were 75%, 31%, and 55%, respectively. The town spent a total of 5.78 million yen (US$56,700) for the campaign. The per-shot cost was estimated as 1,683 yen (US$16.50). From December 1999 through March 2000, a total of 233 town residents (15-101 years old, median 72) were admitted to the town hospital. Of the 233 inpatients, 22 (66-98 years old, median 78) developed respiratory illness, with 4 fatal outcomes. Of these 22 cases, 3 had been vaccinated twice, while 19 had not been vaccinated at all. The relative risk of vaccinees' hospitalization due to respiratory illness decreased to 0.13 compared with that of non-vaccinees (3/1,203 versus 19/1,003, vaccine efficacy = 0.87). Likewise, the relative risk of vaccinees death due to respiratory illness decreased to 0.28 compared with that of non-vaccinees (1/1,203 versus 3/1,003). The results of the Kawaura town's initiative should be helpful for better modeling of mass influenza vaccination campaigns.
Takahashi
H
H
Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Tokyo 162-8640, Japan. hiroshit@nih.go.jp
Tanaka
Y
Y
Ohyama
T
T
Sunagawa
T
T
Nakashima
K
K
Schmid
G P
GP
Okabe
N
N
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D017589:Immunization Programs; D007115:Immunization Schedule; D009980:Influenza A virus / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage*; D007251:Influenza, Human / Q000453:epidemiology / Q000517:prevention & control*; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D014611:Vaccination / Q000191:economics
D007252:Influenza Vaccines