PEDIATRICS Vol. 116 No. 1 July 2005, pp. 153-159 (doi:10.1542/peds.2005-0049)
Effectiveness of the 2003–2004 Influenza Vaccine Among Children 6 Months to 8 Years of Age, With 1 vs 2 Doses
* Clinical Research Unit
Department of Preventive Medicine, Kaiser Permanente Colorado, Denver, Colorado
National Immunization Program, Centers for Disease Control and Prevention, Atlanta, Georgia
Objective. To evaluate the effectiveness of 1 and 2 doses of the 2003–2004 influenza vaccine in preventing medically attended influenza-like illness (ILI) among children 6 to 23 months and 6 months to 8 years of age.
Design and Methods. Outpatient and emergency department visits and immunization records were used to conduct a retrospective cohort study among children 6 months to 8 years of age. ILI and pneumonia and influenza (P&I) outcomes were defined on the basis of International Classification of Diseases, Ninth Revision, codes. Influenza vaccine effectiveness (VE) was calculated as (1 – hazard rate ratio) x 100.
Results. A total of 29726 children were included in the analyses; 17.3% were 6 to 23 months of age. By November 19, 2003, the start of peak influenza activity, 7.5% and 9.9% of children 6 months to 8 years were fully or partially vaccinated against influenza, respectively. For fully vaccinated children 6 to 23 months of age, VE against ILI and P&I was 25% and 49%, respectively. No statistically significant reduction in ILI or P&I rates was observed for partially vaccinated children 6 to 23 months of age (–3% and 22%, respectively). For fully vaccinated children 6 months to 8 years of age, VE against ILI and P&I was 23% and 51%, respectively. For partial vaccination, VE was significant only for P&I (23%).
Conclusions. Despite a suboptimal match between the influenza vaccine and predominant circulating strains, influenza vaccination provided substantial protection for fully vaccinated children and possibly some protection for partially vaccinated children <9 years of age. These findings support vaccinating targeted children even when the vaccine match is suboptimal, and they highlight the need to vaccinate previously unvaccinated children with 2 doses for optimal protection.
Key Words: influenza • vaccine effectiveness • pediatrics • unvaccinated
Abbreviations: ILI, influenza-like illness • P&I, pneumonia and influenza • HRR, hazard rate ratio • VE, vaccine effectiveness • ICD-9, International Classification of Diseases, Ninth Revision • RSV, respiratory syncytial virus • KPCO, Kaiser Permanente Colorado • TCH, the Children’s Hospital • CI, confidence interval • ACIP, Advisory Committee on Immunization Practices
Accepted Mar 15, 2005.
CiteULike 
Connotea 
Del.icio.us 
Digg 
Facebook 
Reddit 
Technorati 
Twitter What's this?
This article has been cited by other articles:
|
|
 |
|
  F.-C. Zhu, H. Wang, H.-H. Fang, J. G. Yang, X. J. Lin, X.-F. Liang, X.-F. Zhang, H.-X. Pan, F.-Y. Meng, Y. M. Hu, et al. A Novel Influenza A (H1N1) Vaccine in Various Age Groups N. Engl. J. Med., October 21, 2009; (2009) NEJMoa0908535v1. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Garcia-Garcia, J. L. Valdespino-Gomez, E. Lazcano-Ponce, A. Jimenez-Corona, A. Higuera-Iglesias, P. Cruz-Hervert, B. Cano-Arellano, A. Garcia-Anaya, E. Ferreira-Guerrero, R. Baez-Saldana, et al. Partial protection of seasonal trivalent inactivated vaccine against novel pandemic influenza A/H1N1 2009: case-control study in Mexico City BMJ, October 6, 2009; 339(oct06_2): b3928 - b3928. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. W. Eisenberg, P. G. Szilagyi, G. Fairbrother, M. R. Griffin, M. Staat, L. P. Shone, G. A. Weinberg, C. B. Hall, K. A. Poehling, K. M. Edwards, et al. Vaccine Effectiveness Against Laboratory-Confirmed Influenza in Children 6 to 59 Months of Age During the 2003-2004 and 2004-2005 Influenza Seasons Pediatrics, November 1, 2008; 122(5): 911 - 919. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. G. Szilagyi, G. Fairbrother, M. R. Griffin, R. W. Hornung, S. Donauer, A. Morrow, M. Altaye, Y. Zhu, S. Ambrose, K. M. Edwards, et al. Influenza Vaccine Effectiveness Among Children 6 to 59 Months of Age During 2 Influenza Seasons: A Case-Cohort Study Arch Pediatr Adolesc Med, October 1, 2008; 162(10): 943 - 951. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. A. Poehling, E. K. Miller, G. A. Weinberg, C. B. Hall, and G. Fairbrother Influenza Virus and Acute Asthma in Children: In Reply Pediatrics, May 1, 2008; 121(5): 1080 - 1080. [Full Text] [PDF]
|
|
|
|
|
|
Committee on Infectious Diseases Prevention of Influenza: Recommendations for Influenza Immunization of Children, 2007-2008 Pediatrics, April 1, 2008; 121(4): e1016 - e1031. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. K. Miller, M. R. Griffin, K. M. Edwards, G. A. Weinberg, P. G. Szilagyi, M. A. Staat, M. K. Iwane, Y. Zhu, C. B. Hall, G. Fairbrother, et al. Influenza Burden for Children With Asthma Pediatrics, January 1, 2008; 121(1): 1 - 8. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. M. Langley MD Release of the statement on influenza for the 2007 2008 season from the National Advisory Committee on Immunization Can. Med. Assoc. J., October 23, 2007; 177(9): 1025 - 1026. [Full Text] [PDF]
|
|
|
|
 |
|
 M. F. Daley, L. A. Crane, V. Chandramouli, B. L. Beaty, J. Barrow, N. Allred, S. Berman, and A. Kempe Misperceptions About Influenza Vaccination Among Parents of Healthy Young Children Clinical Pediatrics, June 1, 2007; 46(5): 408 - 417. [Abstract] [PDF]
|
|
|
|
|
|
D. C. Brousseau, R. G. Hoffmann, A. B. Nattinger, G. Flores, Y. Zhang, and M. Gorelick Quality of Primary Care and Subsequent Pediatric Emergency Department Utilization Pediatrics, June 1, 2007; 119(6): 1131 - 1138. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. M. Shuler, M. Iwamoto, C. B. Bridges, M. Marin, R. Neeman, P. Gargiullo, T. A. Yoder, H. L. Keyserling, and P. D. Terebuh Vaccine Effectiveness Against Medically Attended, Laboratory-Confirmed Influenza Among Children Aged 6 to 59 Months, 2003-2004 Pediatrics, March 1, 2007; 119(3): e587 - e595. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. J. Cox and C. B. Bridges Inactivated and Live Attenuated Influenza Vaccines in Young Children -- How Do They Compare? N. Engl. J. Med., February 15, 2007; 356(7): 729 - 731. [Full Text] [PDF]
|
|
|
|
|
|
L. A. Jackson, K. M. Neuzil, J. Baggs, R. L. Davis, S. Black, K. M. Yamasaki, E. Belongia, K. M. Zangwill, J. Mullooly, J. Nordin, et al. Compliance With the Recommendations for 2 Doses of Trivalent Inactivated Influenza Vaccine in Children Less Than 9 Years of Age Receiving Influenza Vaccine for the First Time: A Vaccine Safety Datalink Study Pediatrics, November 1, 2006; 118(5): 2032 - 2037. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. A. Santibanez, J. M. Santoli, C. B. Bridges, and G. L. Euler Influenza Vaccination Coverage of Children Aged 6 to 23 Months: The 2002-2003 and 2003-2004 Influenza Seasons Pediatrics, September 1, 2006; 118(3): 1167 - 1175. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. B. Walter, K. M. Neuzil, Y. Zhu, M. P. Fairchok, M. E. Gagliano, A. S. Monto, and J. A. Englund Influenza Vaccine Immunogenicity in 6- to 23-Month-Old Children: Are Identical Antigens Necessary for Priming? Pediatrics, September 1, 2006; 118(3): e570 - e578. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. L. Moore, W. Vaudry, D. W. Scheifele, S. A. Halperin, P. Dery, E. Ford-Jones, H. M. Arishi, B. J. Law, M. Lebel, N. Le Saux, et al. Surveillance for Influenza Admissions Among Children Hospitalized in Canadian Immunization Monitoring Program Active Centers, 2003-2004 Pediatrics, September 1, 2006; 118(3): e610 - e619. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. C. Germann, K. Kadau, I. M. Longini Jr., and C. A. Macken From the Cover: Mitigation strategies for pandemic influenza in the United States PNAS, April 11, 2006; 103(15): 5935 - 5940. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Bhat, J. G. Wright, K. R. Broder, E. L. Murray, M. E. Greenberg, M. J. Glover, A. M. Likos, D. L. Posey, A. Klimov, S. E. Lindstrom, et al. Influenza-Associated Deaths among Children in the United States, 2003-2004 N. Engl. J. Med., December 15, 2005; 353(24): 2559 - 2567. [Abstract] [Full Text] [PDF]
|
|
