# Presentation: 660114

##   Influenza Vaccination Coverage Among Children Aged    6-23 Months - United States, 2002-03 Influenza Season

**Stephen L. Cochi, M.D., M.P.H.**
**National Immunization Program**
**National Vaccine Advisory Committee Meeting**
**October 5, 2004**

## Introduction

- Children aged < 2 years are at increased risk for influenza-related hospitalizations.
- Beginning with the 2002-03 influenza season ACIP encouraged vaccination of
- all children aged 6-23 months
- household contacts and out-of-home caregivers for children aged < 2 years.
- CDC published on 9/24/04 influenza vaccination coverage estimates among children aged 6-23 months for the 2002-03 season. (MMWR 23[37]:863-866)

## Methods

- Data from the 2003 National Immunization Survey (NIS) were analyzed.
- Beginning with the 2003 NIS, children’s entire influenza vaccination histories were obtained from their immunization providers.
- Coverage for the 2002-03 season was reported—the first year of the ACIP encouragement.
- Analyses included only those children who were aged 6-23 months during the entire span of September-December 2002.

## Two Measures of Influenza Vaccination Coverage

- Two measures of influenza-vaccination coverage among 6-23 year olds:
- 1+FLU:
- received ≥1 dose during 9/1/02-12/31/02
- Fully Vaccinated:
- Received no doses before 9/1/02 then received 2 doses during 9/1/02-(earlier of 1/31/03 or interview date)  or
- Received ≥1 dose before 9/1/02 then received ≥1 dose during 9/1/02-12/31/02.

## Results

- 7.4% (±0.7) of children aged 6-23 months received one or more influenza vaccinations.
- 4.4% (±0.5) were fully vaccinated.

## Influenza Vaccination Coverage Among Children Aged 6-23 months during the 2002-2003 Influenza Season

## Variability Among States/Urban Areas

- Substantial variability in influenza coverage was observed among states and selected urban areas.
- The percentage of children 6-23 months receiving one or more influenza vaccinations ranged from 2.2% (±2.1) in El Paso County, Texas to 26.6% (±8.0) in Rhode Island.
- The percentage fully vaccinated ranged from 0.3 (±0.4) in Detroit, Michigan to 19.2 (±7.3) in Rhode Island.

## Variability Among States/Urban Areas in 1+Flu Coverage 

## Variability Among States/Urban Areas in Fully Vaccinated Influenza Coverage

## Discussion

- Important baseline for ongoing assessment of influenza vaccination coverage among children aged 6-23 months.
- The NIS will be used for this ongoing assessment.
- During the 2002-03 influenza season, influenza vaccination of healthy children aged 6-23 months was not yet covered by the VFC program or majority of private health plans.
- Beginning with 2003-04 season, VFC now covers influenza vaccination of healthy children aged 6-23 months and household contacts of children aged < 2 years.
- Vaccine supply issue not a factor -- no influenza vaccination shortages or delays in the 2002-03 season.

## Limitations

- Analyses were limited to vaccinations obtained between September-December 2002 (because 2003 NIS interviewing began January 2003) thus vaccinations received later in the season are not counted -- likely to decrease coverage estimates.
- Analyses were restricted to children 6-23 months during the entire period of September-December -- likely to increase coverage estimates.
- Usual NIS limitations: telephone survey, reliance on provider-reported vaccination histories, and larger sampling uncertainty for state and urban area estimates.

## Conclusions

- Influenza-vaccination coverage among children aged 6-23 months was very low during the first year of the ACIP encouragement.
- For the 2004-2005 influenza season, an ACIP recommendation should result in increased coverage.
- Substantial work is needed to fully implement this new recommendation for children aged 6-23 months and household contacts of children < 2 years and to reduce the number of preventable influenza-related hospitalizations among young children.

## Coordinating Center for Infectious Diseases Influenza Operations Plan

- The Coordinating Center for Infectious Diseases convened a workgroup to develop an operations plan for the 2004-2005 influenza season.
- The plan is a guide for an integrated approach to activities that will improve coordination among participating programs to foster a seamless response.
- The plan relies on a core strategy of partnerships with all participating centers and CDC’s partners.

## Activities

- The activities outlined in the plan are not new.
- The activities are listed as “functional operation elements” to provide an internal ‘road map’ for seamless implementation.

## Functional Operations

- Surveillance
- Monitor virus activity, morbidity (ILI), and mortality; provide weekly report
- Monitor pediatric hospitalizations; provide biweekly report
- Vaccine Supply
- Monitor vaccine supply among manufacturers & distributors; provide weekly report
-  Vaccine Safety
- Monitor vaccine adverse events; provide daily reports
- Policy Coordination
- Consult with experts such as ACIP, CSTE, ASTHO, NACCHO, APHL, etc.

## Functional Operations                        (continued)

- Healthcare Impact
- Conduct rapid assessments of impact of influenza on health care delivery
- Strategic National Stockpile
- Heightened alert posture
- Communications
- Will provide timely, accurate, comprehensive, and audience-tailored information about influenza activity, vaccine supply and other topics of importance to the public.