1. Chief, Assessment Branch 44th National Immunization Conference
Who got H1N1 vaccine? Findings from the U.S Influenza Vaccination Surveillance Systems
James A. Singleton, MS
Chief, Assessment Branch
ISD/NCIRD/CDC
44th National Immunization Conference
April 22, 2010
Atlanta, GA
Any one have conference fatigue? H1N1 fatigue? Conference H1N1 fatigue? Thanks for coming to this session. During this talk I will show you the systems we set up to monitor influenza vaccination, present selected findings, and let you know how we plan to monitor this coming fall season.
The findings and conclusions in this presentation are those of the author and
do not necessarily represent the official position of the Centers for Disease Control and Prevention.

2. May 2009: Start Developing Systems to Monitor 2009 H1N1 Influenza Vaccination by October
I got the first from Dr. Schuchat in mid-May to start planning how we would assess H1N1 vaccination during the campaign. This was my first experience in “emergency response”, and I learned I could work a lot harder than I thought. I also learned what a dedicated and talented workforce CDC has, and at this conference had a chance to see the same from local and state staff who conducted the vaccination campaign. The experience also reaffirmed how incredibly patient and supportive my wife is.
5/10/2018 2 2

3. Goals for Monitoring H1N1 Vaccination
Initial assessment
Dose administered reporting
Surveys when coverage high enough
Weekly estimates
Coverage, intent, reasons, opinions, place
Target groups
Children, high-risk, pregnancy, health-care personnel, contacts of infants <6 months
National and State-level

4. 4

5. BRFSS NHFS Internet Panel NHIS NHFS BRFSS SDI NHIS BRFSS NHFS PRAMS
(Rand/Knowledge Networks)
NHIS
NHFS
BRFSS
SDI
NHIS
BRFSS
NHFS
PRAMS
SDI
NHIS
NHFS

6. National 2009 H1N1 Flu Survey (NHFS)
Conducted October 2009 – June 2010 by National Opinion Research Center (NORC)
Random-digit-dialed telephone survey of 6,000 households / month
18% from cell phone-only or mainly households
Additional children from NIS sample frame
~8,000 per month
Weekly national H1N1 & seasonal estimates
Coverage, intent, reasons, opinions, place of vaccination
New system developed for 2009 H1N1 vaccination monitoring *

7. Behavioral Risk Factor Surveillance System (BRFSS)
Conducted October 2009 – June 2010
State-based random-digit-dialed telephone survey of >29,000 households per month
Landline only for influenza-related questions
Children: 46 states, DC, PR, USVI
Adults: states, DC, PR, USVI
Monthly H1N1 & seasonal coverage
Primary source of state-level data
Aggregate “national” estimates
Modification of existing system

8. Other Systems
SDI
Vaccinations administered in provider offices
Rand/Knowledge Networks Internet Panel Surveys of Health-care Personnel (HCP)
Monthly national estimates of H1N1 and seasonal coverage and behavioral factors
Harvard School of Public Health Flu Polls
Eight national polls conducted April 2009 – January 2010
Pregnancy Risk Assessment Monitoring System (PRAMS)
~30,000 women with live births to be surveyed in 31 states
National Health Interview Survey (NHIS)
National in-person survey

10. MMWR Early Release January 15, 2010

12. Enhanced Estimation Approach Improving Precision
Interview Month
Nov Dec Jan Feb
Oct Nov Dec Jan
Vaccination Month

14. Green line = doses shipped per population – maximum possible coverage.
Kept up with doses shipped until demand tanked by end of January

15. Percentage of Cumulative Doses Received by Initial Target and Other Groups by Week, NHFS
The proportion of estimated cumulative doses received by persons in the initial target group was initially over 85%, and had declined to 72% by February 13. By December 19, 39 programs had expanded their H1N1 vaccination effort to the general population.
Based on NHFS interviews from Dec. 27 – Jan. 30, an estimated 166 million persons (95% CI 158 to 174) were in the initial target group, or 56% (95% CI 53% to 58%) of the U.S. civilian, non-institutionalized population aged 6 months or older.
This graph shows cumulative doses; a more direct approach for evaluating change over time in relation to program changes would look at proportion of doses given during a month.
By December 19, 39 programs had expanded
H1N1 vaccination to general population

16. By February, few reported they will definitely get H1N1 vaccination by June for themselves or their child, though some continued to report they will probably get vaccinated.
Proportion saying they definitely will get vaccinated turned out to be good predictor of later vaccination rates, in most groups. Those saying “probably” will get may be those who want the choice but not committed to getting vaccinated.

18. New Analytic Approaches Improving Precision
Kaplan-Meier survival estimates –
Improving the “enhanced” approach
Interview Month
Nov Dec Jan Feb
Oct Nov Dec Jan
Vaccination Month

19. New Analytic Approaches Improving Precision, Filling Gaps
Combining Surveys
Fill in with NHFS for states missing BRFSS data
Improve precision for state-level child estimates
Wc*(0.5*BRFSS child state A NHFS child state A) +
Wa*(0.8*BRFSS adult state A + 0.2*NHFS adult state A)
Wc*(NHFS child state B) +
Wa*(0.9*BRFSS adult state B + 0.1*NHFS adult state B)

20. 72 to 81 million persons vaccinated
How many people received 2009 H1N1 vaccination? How many doses were administered?
72 to 81 million persons vaccinated
81 to 91 million doses administered
(by end of February 2010)
Lower estimates based on combined BRFSS and NHFS
Upper estimates based on NHFS alone
BRFSS estimates < NHFS estimates
Still collecting and analyzing data
Source: MMWR 2010;59:363-8

21. H1N1 Vaccination Coverage as of end of January 2010, BRFSS and NHFS
Source: MMWR 2010;59:363-8

22. Rand study37. 1% H1N1 coverage and 61
Rand study37.1% H1N1 coverage and 61.9% seasonal coverage by mid-January
H1N1 Coverage
Among HCP by
Mid-January
Rand/KN 37%
NHFS %
BRFSS %

23. H1N1 Vaccination Coverage Pregnant Women, BRFSS
As reported in the January 15, 2010 MMWR article, based on BRFSS December 1-27 preliminary data, estimated H1N1 coverage before mid-December was: 38.0% ( ) for pregnant women. Final December estimate was 44.5%.
Each month, H1N1 vaccination rates among currently pregnant women were higher than rates typically achieved (15-25%).
More definitive data from PRAMS forthcoming in >30 states.
Sample sizes were 218, 161, 136, and 185 currently pregnant women in Nov, Dec, Jan and Feb, respectively.
States not included: VT in Nov and Dec; AZ, CT, DC, RI, UT, VT in Jan; DC, VT in Feb.

24. Second H1N1 Dose Receipt, Children 6mo – 9 yrs NHFS, February 28 – March 27 2010
40% (95% CI 35-44) received ≥1 dose
20% (95% CI 17-23) received ≥ 2 doses
Among children receiving at least one dose, 50% received a second dose
By comparison, from the NIS estimates for children 6-23 months, season, 23.4% were fully vaccinated and 40.7% had at least dose of seasonal vaccination, a ratio of 57%.

25. Children -4.2 -5.6 5.5 -2.6 Adults -9.8* -16.5* -11.5* -21.7* All
Racial/Ethnic Disparities in H1N1 and Seasonal Vaccination Coverage by mid-March, NHFS, February 28 – March 27, 2010
Difference in
coverage rate,
Black – White
Hispanic – White
H1N1
Seasonal
Children
-4.2
-5.6
5.5
-2.6
Adults
-9.8*
-16.5*
-11.5*
-21.7*
All
-7.6*
-13.7*
-6.3*
This table shows the difference in H1N1 and seasonal influenza vaccination coverage by mid-March between non-Hispanic blacks and Hispanics compare to non-Hispanic whites.
As is seen for seasonal influenza vaccination, some racial and ethnic disparities in coverage occurred with H1N 1. These differences were significant among adults, but not children, and these differences were of lower magnitude than for seasonal vaccination.
Significant disparities were also observed by levels of income and education, with higher coverage among persons living above the poverty threshold with annual incomes of over $75,000, and for college graduates.
Sample size not sufficient in NHFS monthly samples to reliably estimate disparities among HR or HCP; January BRFSS data are not complete yet to allow update of disparity estimates based on December BRFSS published in the MMWR.
* Coverage rate difference statistically significant, p<0.05

26. NHFS – Opinions

27. NHFS – Place of Vaccination

28. State-specific Influenza Vaccination Coverage Estimates Shared with States
Estimates using December data sent mid-January
Estimates using January data sent mid-February
Detailed tables by age and target group
H1N1 and seasonal rates
seasonal for comparison
Regional and national estimates
Child BRFSS and NHFS estimates combined to provide child data in all states and improve precision

29. Source: MMWR 2010;59:363-8
5/10/2018

30. Are H1N1 and seasonal vaccination coverage by state correlated, this season?
States with higher seasonal coverage during tended to have higher H1N1 coverage, for both children and adults.

31. Is H1N1 coverage by state correlated with past seasonal coverage?
Past season coverage also was predictive of H1N1 coverage in by state. This slide shows a correlation of 51% between season fully vaccinated coverage for children 6-23 months with H1N1 coverage among children of all age groups.
The next slide shows a correlation of 60% between season coverage and H1N1 coverage among adults.
What do these correlations imply? There are many factors that affected H1N1 coverage achieved by state, including but not limited to:
Health care infrastructure, community demand in general and as influenced by timing of influenza activity this year, existing vaccination program, strategies, tactics, efforts and resources for the H1N1 vaccination campaign, and so on. I invite you to give your ideas during the discussion period. These findings do suggest the opportunity to identify best practices and lessons learned to improve influenza vaccination campaigns this fall and during future pandemics.

32. MMWR Article Scheduled for April 30, 2010
State-specific seasonal vaccination
Same methods as April 2 H1N1 article
Kaplan-Meier survival estimates of vaccinations through January using interview data collected through February
Combine BRFSS and NHFS state-level estimates

33. Summary of H1N1 Vaccine Coverage
By end of February, >70 million people had received >80 million doses of H1N1 vaccine
Most doses went to target groups
Coverage was higher in children than adults
An estimated 31-39% of health care workers vaccinated
An estimated 30-45% of pregnant women vaccinated
Of children <10 years who were vaccinated, half received their 2nd dose
H1N1 vaccine coverage in adults was significantly higher in whites than blacks or Hispanics
H1N1 coverage did not differ significantly by race or ethnicity among children

34. Summary of H1N1 Vaccine Coverage
Perceived effectiveness and safety of H1N1 vaccine was lower than seasonal initially but improved during the campaign
Demand apparently dropped with perception of risk
School was location of vaccination for 30% of children
Large variation in H1N1 coverage by state, particularly for children
High levels of childhood coverage achieved in some states
and past seasonal coverage by state was predictive of coverage for 2009 H1N1 monovalent vaccine

35. Caveats
Vaccination status and target group status based on self or parental report
Respondents may have confused H1N1 and seasonal vaccinations
Non-response bias may remain after weighing adjustments
NHFS estimates > BRFSS estimates
Survey estimates of coverage consistent with vaccination patterns observed with SDI data
In past seasons, self/parental report tends to overestimate seasonal influenza vaccination coverage.
This season, it is also possible that some respondents confused H1N1 and seasonal vaccinations.
NHFS is a survey specifically about influenza and may be some selective participation among those more likely vaccinated as compared to general behavioral health survey such as BRFSS.

36. Post-season Evaluation Using Survey Data
Developing season research agenda
Provide information to improve planning and implementation of next flu season and future pandemics
Implementation – what worked and what didn’t
Collect data from states on their program activities
Relate activities to vaccination coverage
Number and type of providers enrolled as H1N1 vaccinators
Proportion of vaccine given through public venues
School-located vaccination
Case studies based on states with high and low coverage
Provide BRFSS data analysis assistance to states
Team of 8+ full time staff
5/10/2018

38. Plans for 2010-2011 Season Influenza Vaccination Surveillance
BRFSS adult data monthly
Children from NIS sample frame
Sample size ~8,000 per month
National weekly estimates
State-level estimates after accumulate several months of data
“Snapshot” surveys, n~1,400
National and in 10 selected metro areas
Mid-season and March snapshots
Vaccination, opinions, behaviors
Special population surveys, mid-season & March
Health care personnel
Pregnant women
PRAMS, SDI, College Health Database
After this season, the status quo of having influenza vaccination estimates from BRFSS, NHIS and NIS 12 to 18 months after the end of the season is no longer adequate. Based on what we learned so far implementing the expanded systems this season, we have planned the system for this season.

39. Intent for 2010-11 Influenza Vaccination April 3-10, 2010, NHFS
Please think ahead to the upcoming flu season, that is, the flu season that will begin in the fall of 2010.  How likely are you to get a seasonal flu vaccination during the upcoming flu season?  Would you say you: (1) will definitely get one (2) will probably get one (3) will probably not get one (4) or, will definitely not get one (77) DON’T KNOW (99) REFUSED

40. Intent for 2010-11 Influenza Vaccination April 3-10, 2010, NHFS
H1N1 and seasonal vaccination coverage among the NHFS weekly sample April 3-10 shown here for reference. Among this sample, over 40% of parents report their child will definitely get seasonal vaccination for the season, similar to the season, and another 24% report they probably will have their child vaccinated. We found from NHFS that definite is predictive of behavior but probably is not. Also there are many caveats with trying to predict demand, e.g., several months before campaign, communications not yet widespread about 2009 H1N1 component in upcoming vaccine, what happens with influenza activity, and so on.
For adults, 34% in this week’s sample report intending to definitely get influenza vaccination this upcoming season, less than reported seasonal vaccination.
6m-18y ± ±7.1
19-24y ± ±17.6
25-49y ± ±7.2
50-64y ± ±4.9
65+y ± ±5.3
All (6m+) 36.5± ±3.7
Children
Adults

41. Conclusions
CDC established a comprehensive vaccine coverage monitoring system for 2009 H1N1
Results from this system helped CDC and possibly states manage the campaign
Further analysis of data aimed at providing useful information for future seasons
Lessons learned from assessment this season already applied to plans for
States should consider use of BRFSS to collect additional influenza vaccination data
Children (got vaccinated, place of vaccination)
Adult health-care personnel

42. 5/10/2018

43. Acknowledgements 2009 H1N1 Vaccine Coverage Monitoring Team
CDC/NCIRD – Barbara Bardenheier, Carla Black, Daoling Bi, Leah Bryan, Helen Ding, Gary Euler, Carolyn Furlow, Amparo Gonzalez-Feliciano, Charles LeBaron, Pengjun Lu, Elizabeth Luman, Liz Monsell, Rachel Patzer, Tammy Santibanez, Rosana Setse, Jim Singleton, Phil Smith, Larry Wilkinson, Carla Winston, Karen Wooten, David Yankey, Surasak Youngpairoj, Fan Zhang, John Zhang, Zhen Zhao
CDC/BRFSS -- Lena Balluz, Machell Town
CDC/NCBDDD – C. J. Alverson
CDC/NCCDPHP – Lawrence Barker
CDC/NCHS – Marcie Cynamon, Kathleen O’Connor
NORC – Ken Copeland, Nick Davis, Margrethe Montgomery, Kirk Wolter
SDI -- Laurel Edelman, Joel Greenspan
Members of the team please stand and be recognized! 43

44. Jim Singleton JSingleton@cdc.gov
Thank you
Jim Singleton

45. CRA: An early monitoring tool in the H1N1 event
Each Project Area responsible for
Sending data to CRA for each reporting period
Aggregating all doses administered by age group and dose number for all clinics in the jurisdiction
Reporting based on the MMWR week
Sunday – Saturday
Reporting required weekly to CDC by Tuesday 11:59 pm of respective time zone
14,788,795 H1N1 doses were reported to the CRA system
As an early monitor technique for the H1N1 response. CDC stood up the Countermeasure and Response Administration (CRA) system. This system was activated as an initial way to monitor uptake of the vaccine in select age groups. Each state was required to collect aggregate levels of vaccine information and report the aggregate counts to the CRA systems in various different options. Once the amount of vaccine reached a certain threshold ~40 million doses distributed. After the this threshold was hit the required reporting to CDC was stopped. A more in-depth presentation on doses administered monitoring was presented at 9am session this morning 45

47. Receipt of H1N1, Seasonal, or Both Types of Influenza Vaccination by mid-March, NHFS, February 28 – March
Children were more likely than adults to get both H1N1 and seasonal vaccination by mid-January, while adults were more likely to get seasonal vaccination only. Overall, 53% of children and 47% of adults had received an influenza vaccination of either type.
The ACIP is working on dosage recommendations for this fall, e.g. for children who need only one “seasonal” dose this upcoming fall and did not receive any doses of monvalent 2009 H1N1 vaccine.

48. MMWR Early Release January 15, 2010

49. MMWR Early Release January 15, 2010

50. Within-Season Uses of Influenza Vaccination Data
At state level
Promote vaccination for National Influenza Vaccination Week Jan
Local briefings with state government officials
Evaluate progress of state vaccination campaign
Some states using their BRFSS data on their own
At federal level
Weekly slide set to H1N1 Vaccine Task Force
Brief CDC leadership and HHS on progress
Identify states doing very well or lagging behind
Estimate number of persons vaccinated in Emerging Infection Program sites conducting active surveillance of Guillian Barré Syndrome 50 50

51. Cumulative doses administered in physician offices for seasonal vaccine and H1N1 vaccine through April 10, 2010, SDI

52. Weekly uptake of seasonal and H1N1 influenza vaccines through April 10, 2010, SDI

53. H1N1 Influenza Vaccine Uptake in Physician Offices, through April 10, 2010, SDI53 53

54. NIS Frame Special survey BRFSS (optional) NHIS Snapshots BRFSS SDI
(child optional)
SDI
NHIS
Special Survey
BRFSS
PRAMS
SDI
NHIS
Snapshots