Rapid identification of herd effects with the introduction of serogroup C meningococcal conjugate vaccine in Ontario, Canada, 2000-2006.
In 2001, Canada's National Advisory Committee on Immunization endorsed a meningococcal serogroup C conjugate vaccine, which appears to provide durable serogroup-specific immunity while reducing nasopharyngeal carriage. With reference to direct and indirect effects on case occurrence, we sought to evaluate recent trends in the incidence of invasive meningococcal disease (IMD) in Ontario. Analyses included all IMD cases reported between 2000 and 2006 to the Ontario Central Public Health Laboratory. Poisson models incorporating terms for age, sex and seasonal oscillation identified a significant downward trend in disease occurrence, which was strongest in serogroup C cases and not evident when serogroup C strains were excluded from the analysis. Among age groups not targeted by the vaccine program serogroup C, IMD displayed a pattern of decreasing incidence that was not present in non-serogroup C disease. These apparent dramatic effects of conjugate C vaccine (both direct and indirect) may be important in the implementation and evaluation of vaccine policy in other jurisdictions.
Kinlin
Laura M
LM
The Research Institute of the Hospital for Sick Children, Toronto, Ontario, Canada; The University of Toronto, Toronto, Ontario, Canada.
Jamieson
Frances
F
Brown
Elizabeth M
EM
Brown
Shirley
S
Rawte
Prasad
P
Dolman
Sharon
S
Drews
Steven J
SJ
Fisman
David N
DN
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D032521:Immunity, Herd / Q000276:immunology*; D007223:Infant; D008297:Male; D008585:Meningitis, Meningococcal / Q000453:epidemiology / Q000276:immunology* / Q000517:prevention & control*; D022401:Meningococcal Vaccines / Q000276:immunology*; D008875:Middle Aged; D038542:Neisseria meningitidis, Serogroup C / Q000276:immunology*; D009864:Ontario / Q000453:epidemiology; D012737:Sex Factors; D018074:Vaccines, Conjugate / Q000276:immunology; D055815:Young Adult
D022401:Meningococcal Vaccines; D018074:Vaccines, Conjugate