1. Vaccination coverage of U. S
Vaccination coverage of U.S. adolescents ages years, National Immunization Survey-Teen, 2006
March 17, 2008
Nidhi Jain MD MPH
Immunization Services Division
National Center for Immunization and Respiratory Diseases
Centers for Disease Control and Prevention

3. Adolescent vaccine assessment
In the past, adolescent vaccines have been assessed from:
National Health Interview Survey (NHIS)
Local surveys
NIS-Teen is the first national survey to assess adolescent vaccines with provider-reported vaccinations
In the past, assessment of adolescents vaccines has been from:
NHIS using parental recall of immunizations or looking at immunization cards during household surveys
Local surveys in certain states doing their own methods
NIS-Teen is first national survey to assess adolescent vaccines with vaccinations reported from providers

4. Adolescent vaccination schedule
Here is the proposed 2008 adolescent vaccine schedule.
The first three vaccines are the new vaccines, Tdap, meningococcal vaccine and HPV, which are recommended for routine administration to adolescents aged year with catch up recommended at years at the earliest opportunity.
Next we have the vaccines recommended for children with high risk conditions, such as pneumoccal vaccine, influenza, and hepatitis A.
On the bottom are the infant and childhood vaccines or catch up vaccines from childhood which providers should review to make sure adolescents had completed the series in childhood. And that includes hepatitis B, polio, MMR and varicella

5. Health care visit
MMWR published with recommendations for an adolescent visit at age years
Supported by ACIP, AAP, AMA, AAFP
Visit is a time to “catch-up” childhood vaccines and to administer new adolescent vaccines
Visit is a time to deliver other preventive services, ie. behavioral counseling
One important point to note from this schedule is that the best time for adolescents to receive these vaccines are at the year old visit and this visit has been recommended by the ACIP, AMA, AAP, and AAFP.
This is a visit that should happen for all adolescents when providers can review and administer the catch up vaccines as needed and administer the new vaccines. It is also a time for other preventive services to be given to adolescents, such as behavioral counseling.
Of course, if a teen did not get the vaccines at age then they should get the vaccines at the earliest opportunity.

6. Healthy People 2010 objectives
For adolescents age years 90% coverage of:
3+ doses of HepB
2+ doses of MMR
1+ dose of Td or Tdap
1+ dose of varicella (among those without prior history of disease)
And lastly, I would like to mention The Healthy People 2010 objectives that have been established for adolescent vaccinations which is 90% coverage of
3+ doses of HepB
2+ doses of MMR
1+ dose of Td/Tdap
1+ dose of varicella (among those without prior history of disease) and for years olds

7. Methods

8. NIS-Teen methodology
Uses National Immunization Survey (NIS) sample frame methodology
Random digit dial telephone survey
National sample of parents/guardians of adolescents years old
Consent obtained to contact providers
Provider record check for provider reported immunizations
The NIS-Teen uses the sample frame methodology as the infant NIS which you just heard about for months old
This is a Random digit dial telephone survey
For the NIS- Teen we interviewed a National sample of parents/guardians of adolescents years old to obtain their immunization histories from either immunization cards or recall
We also obtained Consent from parents to contact immunization providers of the teens
This is so that we could send a Provider record check to the provider to collect their documented vaccination information

9. NIS-Teen 2006 Conducted Oct 2006 - Feb 2007
Collected information for adolescents born between Oct 7, 1988 to Feb 7, 1994
5,468 household interviews conducted
56.2% household response rate
2,882 teens had adequate provider records to determine vaccination coverage
52.7% of the adolescents with completed household interviews
the NIS-Teen was conducted Oct Feb 2007
information was collected for adolescents born between Oct 7, 1988 to Feb 7, 1994
A total 5468 households were interviewed giving us a household response rate of 56.2%
And out of those households, 2882 teens had adequate provider records returned to determine vaccination Coverage estimates which is 52.7% of adolescents with completed household interviews

10. NIS-Teen 2006 Sample Total sample released 341,512 Resolved sample
281, (82%)
Households identified
79, (28%)
Households screened
64, (81%)
Eligible households
6, (10%)
Completed interviews
5, (84%) ,468 adolescents
Gave consent
4, (77%)
Adolescents with adequate provider records returned
(53%)
Just to show you how large this survey is and how we got our sample,
We had an initial sample of about 340,000 telephone numbers
281,000 telephone numbers or 82% were determined to be working numbers.
From that 79,000 or 28% were identified to be actual households and
we were able to screen 64,000 households or 81%.
After screening, it was determined that, 6500 or 10% had an age eligible teen and from that 5481 or 84% completed the household teen survey.
Removing some teens because of ineligible birthdates, we had a
total 5468 households interviewed and
only 77% gave consent to contact their providers leaving us with 4192 that did.
And out of that number, 2882 teens had adequate provider records returned to determine vaccination Coverage estimates which is 52.7% of adolescents with completed household interviews

11. Adequate provider records
Defined similarly to infant NIS using key indicators (match HH to provider)
Need to make sure all potential vaccine providers have been contacted
Average number of providers to teen = 1.8 (infant NIS is 1.3)
Defined similarly to the infant NIS looking at key indicators such as whether the household reported immunizations match with the provider reported immunizations and other factors
This was looked at to make sure that all potential vaccination providers had been contacted
What we found from the survey was that the average number of providers per teen was 1.8, compared to 1.3 with the infant NIS

12. Vaccines Evaluated “Catch-up” infant vaccines
Hepatitis B
MMR
Varicella (vaccine and disease)
“New” adolescent vaccines
Td/Tdap
MCV4
HPV
The vaccines we evaluated from the survey included all the vaccines mentioned in the adolescent schedule, except for polio.
Today I will talk about the Catch-up’ vaccines
Hepatitis B, MMR, Varicella (vaccine and disease)
And the new recommended Adolescent vaccines
Td/Tdap, MCV4, and HPV
As well as influenza

13. Analysis
Used SUDAAN software because of complex weighting of survey data
Determined point estimates and 95% confidence intervals
Statistical tests used:
Used chi-square and t-tests for differences
To conduct the analysis, we used SUDAAN software because of the complex weighting of the survey data
We determined point estimates and 95% confidence intervals
And we used chi square and t-tests to test differences

14. Results

15. Estimated vaccination coverage among adolescents 13-17 years of age, NIS-Teen, 2006
This slide shows overall vaccination coverage among adolescents years of age for the vaccines I mentioned.
Overall vaccination coverage was 86.9% for 2+ doses of MMR, 81.3% for 3+ doses of Hepatitis B, 65.5% coverage for varicella vaccine among adolescents without any previous history of disease.
Only 60.1% of adolescents in our sample had received either a Td or Tdap vaccine since age 10 years and
11.7% of adolescents had received the meningococcal vaccine.
*Varicella coverage is among teens without a reported history of disease. Td/Tdap is since age 10 years
MMWR ;56:

16. Estimated vaccination coverage for 2+ MMR by age, NIS-Teen
Going into more detail by vaccine type, This slide shows coverage for 2 or more doses of MMR by age and Coverage did not differ significantly by age
MMWR ;56:

17. Estimated vaccination coverage for 3+ HepB by age, NIS-Teen
Here is coverage for hepatitis B vaccine by age where we see that coverage is higher among the younger teens years old compared to the older teens 16 and 17 years old. This is somewhat expected since the younger teens were likely vaccinated at birth when universal recommendations were made for hepatitis B vaccine in 1991 and the older teens were born after that year. However, the older teens should be receiving hep B vaccine in catch-up campaigns for adolescents and also through middle school requirements in some states.
MMWR ;56:

18. Estimated varicella protection (by disease or 1+ vaccine) by age, NIS-Teen
89.5
89.3
90.5
88.3
90.4
89.6
Here are the results about varicella disease and vaccination. We had a question for the parents and the providers to indicate whether the child had a previous history of varicella disease. So here you can see that about 90% of adolescents are protected from varicella - either through having had the disease or from receiving at least one dose of the vaccine. The orange portion of the bar represents the proportion of teens who have had varicella disease, and the blue portion represents the proportion of teens who had received at least one dose of the vaccine.
You can see among the older teens, more of them have had the disease compared to the younger teens.
MMWR ;56:

19. Estimated vaccination coverage of 1+ Td or Tdap since age 10 yrs by age, NIS-Teen
48.3
57.1
64.2
62.7
68.6
60.1
In an earlier slide I showed coverage for receipt of either Td or Tdap vaccine since age 10 year. Here coverage has been broken down by vaccine type and by age.
Coverage with Td vaccine is in orange and with Tdap vaccine is in blue.
Coverage with either Td or Tdap is higher among the older teens – this is expected since they have had more time to get vaccinated however the older teens are more likely to have received Td while the younger teens received
Tdap which is also not surprising since Tdap has only been out since 2005.
One reason why older teens may not have received Tdap vaccine is that a 5 year interval is routinely recommended after receiving Td vaccine, however a shorter interval may be appropriate under certain circumstances. Maybe providers are waiting the interval out before giving Tdap. We are conducting additional analysis to look at this issue.
MMWR ;56:

20. Estimated vaccination coverage of meningococcal vaccine (MCV4) by age, NIS-Teen
Here is coverage of meningococcal vaccine by age. Coverage did not differ significantly among year olds, however, coverage was significantly lower among 17 year olds.
MMWR ;56:

21. HPV vaccine coverage
1.0% among female adolescents

22. Progress toward HP2010 objectives among adolescents aged 13-15 years, NIS-Teen
We also assessed progress towards achieving HP2010 objectives of 90% coverage among adolescents years of age. As you can see, we are below the objectives for the 4 specified vaccines in the 2010 objectives.
*Varicella coverage is among teens without a reported history of disease. 1+Td/Tdap is booster dose
MMWR ;56:

23. Estimated Td or Tdap vaccination coverage by year in which adolescent reached 13th birthday
To assess whether teens are receiving vaccinations during the pre-teen years or at ages years, we looked at vaccination coverage of Td or Tdap by age 13 years. On the x axis is the year the teen turned 13 and on the y axis is the % vaccinated by age 13 years.
So looking at the cohort of teens who turned 13 in 2002 or our 17 years olds in the survey, only 22.7% of them had received the Td booster by the time they turned 13. However, you can see an increase in each cohort where of teens who turned 13 in 2006, 41.7% of them had already received a Td or Tdap booster which shows that there has been improvement in the number of teens who are receiving shots during the pre-teen years.
Td or Tdap since age 10 years. MMWR ;56:

24. Limitations
Bias may remain due to non-response and missing households without landline phones
Assumes coverage among adolescents with adequate provider data is the same among adolescents without adequate provider data
May have missed some vaccinations if provider records are not complete (i.e. missing vaccinations given in non-traditional settings)
Low response rates for households, getting consent, getting adequate provider records
Bias may remain due to survey non-response and missing households without landline phones
Also by Assuming that coverage among adolescents with adequate provider data is the same as coverage among adolescents without adequate provider data may either underestimate or overestimate the rates
We May also have missed some vaccinations if some of the provider records that we have and assume to be complete are not complete (such as they can be missing vaccinations that were given in non-traditional settings like emergency rooms)
And lastly, we had low response rates for the total households, households who gave consent, and the number of adolescents who we got adequate provider data

25. Conclusions
NIS-Teen is able to give national estimates of vaccination coverage using provider reported vaccination histories
Vaccination coverage of adolescents
High for catch up infant vaccines (MMR, HepB)
Low for Td/Tdap and varicella
Very low for new vaccines (Tdap, MCV4, and HPV)
HP 2010 objectives have not been met for any of the specified vaccines
In conclusion, we have found from this analysis of the NIS-Teen that
Coverage of “catch-up” infant vaccines (MMR, HepB) are high
Coverage of Td/Tdap and varicella vaccine is low
Coverage of new vaccines are low, but it is not surprising since vaccines were only licensed 2 years ago
HP 2010 objectives have not been met for 4 vaccines, hep B, MMR, Td, and varicella vaccines

26. Plans
Additional analyses are being conducted with the 2006 NIS-Teen, including:
Age of receiving vaccinations
Comparison of parent and provider reported immunization histories
Vaccine specific papers
The NIS-Teen is now an annual survey
2007: 4th quarter only, national estimates
2008 and beyond: all 4 quarters, national and state-specific estimates
Additional analyses are being conducted with the 2006 NIS-Teen, including:
An analysis of the Age of receiving vaccinations
Comparison of parent and provider reported immunization histories
Vaccine specific papers
The NIS-Teen is now an annual survey
2007: 4th quarter only, national estimates
2008 and beyond: all 4 quarters, national and state-specific estimates

27. Thank you Jim Singleton Shannon Stokley Abby Shefer Larry Wilkinson
NORC
Adolescent vaccination implementation workgroup