Lack of efficacy of Haemophilus b polysaccharide vaccine in Minnesota.
We evaluated the efficacy of Haemophilus b polysaccharide vaccine in children in Minnesota using a case-control study. The vaccine became available in Minnesota in August 1985. During the subsequent 28 months, 88 cases of invasive H influenzae type b disease were identified in children 24 to 71 months of age, the group targeted for vaccination. Of the 88 cases, 36 (41%) occurred in vaccinated children. Fifty-eight (33%) of 176 controls were vaccinated during a similar period. The vaccine's protective efficacy for children with any history of vaccination was -58% (95% confidence interval = -204% to 18%). The vaccine's protective efficacy for children who were most likely to be protected by vaccination was -55% (95% confidence interval = -238% to 29%). Our results indicate that vaccination with Haemophilus b polysaccharide vaccine had no effect in preventing H influenzae type b disease in Minnesota children.
Osterholm
M T
MT
Acute Disease Epidemiology Section, Minnesota Department of Health, Minneapolis 55440.
Rambeck
J H
JH
White
K E
KE
Jacobs
J L
JL
Pierson
L M
LM
Neaton
J D
JD
Hedberg
C W
CW
MacDonald
K L
KL
Granoff
D M
DM
D016667:Bacterial Capsules; D001428:Bacterial Vaccines / Q000008:administration & dosage; D002675:Child, Preschool; D004812:Epidemiologic Methods; D005260:Female; D006192:Haemophilus Infections / Q000517:prevention & control*; D018073:Haemophilus Vaccines; D006193:Haemophilus influenzae; D006801:Humans; D008297:Male; D008910:Minnesota; D011135:Polysaccharides, Bacterial; D011159:Population Surveillance; D011897:Random Allocation; D013223:Statistics as Topic; D013997:Time Factors
D001428:Bacterial Vaccines; D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine; D011135:Polysaccharides, Bacterial