tetano
Editor, Senior Moderator
Vaccine
Available online 18 May 2013
In Press, Uncorrected Proof ? Note to users
Cover image
Short communication
Seasonal influenza vaccine effectiveness in pre- and full-term children aged 6?23 months over multiple seasons
Shixin Shena,
Michael A. Campitellid,
Andrew Calzavarad,
Astrid Guttmannb, d, g,
Jeffrey C. Kwonga, c, e, f, Corresponding author contact information, E-mail the corresponding author
a Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
b Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Canada
c Department of Family and Community Medicine, University of Toronto, Toronto, Canada
d Institute for Clinical Evaluative Sciences, Toronto, Canada
e Public Health Ontario, Toronto, Canada
f University Health Network, Toronto, Canada
g Department of Paediatrics, Hospital for Sick Children, Toronto, Canada
http://dx.doi.org/10.1016/j.vaccine.2013.05.011
Highlights
?
We studied influenza vaccine effectiveness among children aged 6?23 months.
?
Influenza-coded ambulatory visits were the main outcome under investigation.
?
Only full vaccination was effective, and only among full-term children.
?
Further analyses suggest the observed benefits were not due to confounding.
?
Future studies of vaccine effectiveness in preterm children are warranted.
Abstract
Introduction
This study aimed to determine the effectiveness of seasonal influenza vaccine in pre- and full-term children aged 6?23 months.
Methods
We examined a cohort of 683,354 young children (7.7% preterm) over five influenza seasons (2004?2005 to 2008?2009) in Ontario, Canada. Vaccine effectiveness was estimated using influenza-coded ambulatory visits during virologically-confirmed influenza season periods as the outcome and multivariable Cox proportional hazards modeling.
Results
Full vaccination was associated with a 19% reduction in influenza-coded ambulatory visits (HR = 0.81; 95% CI, 0.68?0.97) in all children, and an 18% reduction in full-term children (HR = 0.82; 95% CI, 0.68?0.99). We did not find significant vaccine effectiveness for preterm children. No benefit was found for partial vaccination.
Conclusions
In children younger than two years, only full influenza vaccination is associated with reduced influenza-coded ambulatory visits. Since the effectiveness of influenza vaccination in preterm children remains uncertain, further study of this highly vulnerable population is warranted.
http://www.sciencedirect.com/science/article/pii/S0264410X13005896
Available online 18 May 2013
In Press, Uncorrected Proof ? Note to users
Cover image
Short communication
Seasonal influenza vaccine effectiveness in pre- and full-term children aged 6?23 months over multiple seasons
Shixin Shena,
Michael A. Campitellid,
Andrew Calzavarad,
Astrid Guttmannb, d, g,
Jeffrey C. Kwonga, c, e, f, Corresponding author contact information, E-mail the corresponding author
a Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
b Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Canada
c Department of Family and Community Medicine, University of Toronto, Toronto, Canada
d Institute for Clinical Evaluative Sciences, Toronto, Canada
e Public Health Ontario, Toronto, Canada
f University Health Network, Toronto, Canada
g Department of Paediatrics, Hospital for Sick Children, Toronto, Canada
http://dx.doi.org/10.1016/j.vaccine.2013.05.011
Highlights
?
We studied influenza vaccine effectiveness among children aged 6?23 months.
?
Influenza-coded ambulatory visits were the main outcome under investigation.
?
Only full vaccination was effective, and only among full-term children.
?
Further analyses suggest the observed benefits were not due to confounding.
?
Future studies of vaccine effectiveness in preterm children are warranted.
Abstract
Introduction
This study aimed to determine the effectiveness of seasonal influenza vaccine in pre- and full-term children aged 6?23 months.
Methods
We examined a cohort of 683,354 young children (7.7% preterm) over five influenza seasons (2004?2005 to 2008?2009) in Ontario, Canada. Vaccine effectiveness was estimated using influenza-coded ambulatory visits during virologically-confirmed influenza season periods as the outcome and multivariable Cox proportional hazards modeling.
Results
Full vaccination was associated with a 19% reduction in influenza-coded ambulatory visits (HR = 0.81; 95% CI, 0.68?0.97) in all children, and an 18% reduction in full-term children (HR = 0.82; 95% CI, 0.68?0.99). We did not find significant vaccine effectiveness for preterm children. No benefit was found for partial vaccination.
Conclusions
In children younger than two years, only full influenza vaccination is associated with reduced influenza-coded ambulatory visits. Since the effectiveness of influenza vaccination in preterm children remains uncertain, further study of this highly vulnerable population is warranted.
http://www.sciencedirect.com/science/article/pii/S0264410X13005896