1. Influenza vaccination coverage among pregnant women National 2009 H1N1 Flu Survey (NHFS) season
Helen Ding, MD, MS,MSPH
Epidemiologist, Chenega Government Consulting , LLC
Contractor, Assessment Branch, Immunization Services Division,
NCIRD, CDC
National Immunization Conference Washington D. C.
March 2011
National Center for Immunization & Respiratory Diseases
Assessment Branch, Immunization Services Division

2. Acknowledgement CDC/NCIRD/Immunization Service Division
Tammy A. Santibanez
Gary L. Euler
Peng-jun Lu
James A. Singleton
Cindy Weinbaum
CDC/NCCDPHP/Division of reproductive health
Denise J. Jamieson
CDC/NCIRD/Influenza Division
Lisa A. Grohskopf
The whole talk is based on the paper that just been accepted for publication by American journal of Obstetrics and Gynecology. I would like acknowledge all our co-authors from AB, Influenza division and Division from Reproductive Health.

3. Background
Pregnant women are at increased risk of morbidity and mortality from influenza because of physiological changes during pregnancy
(Rasmussen, Jamieson and Bresee, Emerg Infect Dis 14:95-100, 2008)
Influenza vaccination protects both pregnant women and their newborns from influenza and its complications
(Zaman et al., N Engl J Med 359: , 2008; Eick A. et al, Arch Pediatri Adolesc Med 2010; DOI: /archpediatrics )

4. Vaccination recommendations
Seasonal influenza vaccination was first recommended for pregnant women by the Surgeon General in the 1960s
Since 2004, the Advisory Committee of Immunization Practice (ACIP) and American College of Ob/Gyn (ACOG) have recommended that all women who are or will be pregnant during the influenza season be vaccinated regardless of trimester
For season, ACIP recommended all pregnant women should receive both H1N1 monovalent and seasonal trivalent vaccines.
The recommendation for pregnant women has evolved with some variation over time regarding the strength and timing of the recommendation

5. Behavioral Risk Factor Surveillance Systems (BRFSS)
Surveillance systems for vaccination pregnant women Influenza Season
Behavioral Risk Factor Surveillance Systems (BRFSS)
National Health Interview Survey (NHIS)
Pregnancy Risk Assessment Monitoring System (PRAMS)
National 2009 H1N1 Flu Survey (NHFS)
As a response to pandemic, several surveillance systems were established or adapted to monitor influenza vaccination .
Here I listed those that related to pregnant women.
BRFSS is a state-based RDD household telephone survey. The pregnancy status were measured for all women yrs old by a question asking whether they were currently pregnant during the interview. As pregnant women is a dynamic cohort, it didn’t capture the women that were pregnant during the flu season.
NHIS is a national representative cross-sectional household survey. The pregnancy is also measured by the currently pregnancy status during interview. Because of the interview were conducted face-to face, it is considered as a gold standard for the estimates. But the data won’t available until at least a year post the influenza season.
PRAMS is a mail-in survey that sampled from pregnant women who had a live birth. It contains birth certificate data. About 30 states participated the flu supplement survey in the season. It is the largest survey on pregnant women. However the data won’t available until at least 16 months post influenza season.
National 2009 H1N1 flu survey

6. NHFS survey Random digit dial telephone survey
October 2009 through June 2010
Landline
Cell-phone only or mainly
Collected both seasonal (trivalent) and 2009 H1N1 (monovalent) vaccination
Measurement for pregnant women
Women currently pregnant during interview
Women that were pregnant any time October 2009 through January 2010

7. Influenza vaccination coverage estimates among pregnant women in years prior to 2009-10
: Annual coverage estimates among currently pregnant women of NHIS* were 8%-19%
Levels among other high-risk adults the same age were not even as low—18%-30%.
National Health Interview Survey: 75% of interviews conducted in-person in the home. Women (n~ ) were asked if they had received influenza vaccination in past 12 months . Interviews conducted Jan –Dec.

8. Objectives
To assess influenza vaccination coverage among pregnant women for the pandemic season
To compare vaccination coverage to non-pregnant women with high-risk conditions
To examine factors associated with vaccination coverage

9. Methods Dataset : NHFS Interviews conducted April –June 2010
Study population: women yrs old
Pregnant women with other high-risk
conditions (HRC)
Pregnant women without other HRC
Non-pregnant women with HRC
Non-pregnant women without HRC
High-risk conditions (HRC) refers to conditions included in the ACIP influenza recommendations that are associated with serious complications following influenza infection
Pregnancy : Pregnant anytime October 2009-January 2010
Vaccination period: October January 2010

10. Analyses
Distributions of selected characteristics of the three groups of women
Demographic characteristics
Medical care utilization
Personal opinions on infection and vaccines
Univariate: vaccination coverage by above characteristics
Multivariable analysis:
Multiple logistic regression models for all women yrs old
Adjusted prevalence ratios based on adjusted coverage
SAS 9.2 and SAS callable SUDDAN 10.0 used for analyses to take into account the complex survey design

11. Sample size 3,839 women 18-49 years old were selected for this study
Pregnant women: 244 (6%) (50 with HRC, 194 without HRC)
Non-pregnant women with HRC: 832 (21%)
Non-pregnant women without HRC: 2,763 (73%)

12. SELECT RESULTS

13. Influneza vaccination coverage pregnant women

14. Vaccination coverage by three women groups

15. High-risk conditions: Influenza vaccination coverage among pregnant women

16. Race/ethnicity: Influenza vaccination coverage among pregnant women

17. Doctor’s recommendation: 2009 H1N1 vaccination coverage among three groups of women

18. Place of vaccination: among pregnant women

19. Reasons for not getting H1N1 vaccination: among pregnant women

20. Multivariable Analyses

21. Factors associated with 2009 H1N1 vaccination among all women 18-49 yrs

22. Factors associated with seasonal vaccination among all women 18-49 yrs
*Adjusted for other covariates included n the model :HRC, income, and number of children in the household.

23. Summary
About half of pregnant women received influenza vaccination in the season,
much higher than coverages reported in previous seasons
Pregnant women achieved higher vaccination level for H1N1 vaccine compared to non-pregnant women with/without HRC.

24. Summary
Receipt of a health care provider’s recommendation for vaccination, perceived effectiveness of influenza vaccination, and perceived high chance of influenza infection were independently associated with higher H1N1 and seasonal vaccination.

25. Commentary
The relative high coverage among pregnant women than the other two groups may due to the following reasons
The effectiveness of public health massaging on the importance of influenza vaccination among pregnant women
Extensive vaccination campaign and outreach efforts toward pregnant women care providers through new partnerships between CDC and provider communities
The more exposure of pregnant women to health care providers because of prenatal care visits schedule

26. Commentary(con’t)
In addition, compared to prior seasons, the dramatic increase of the coverage estimates among pregnant women for the season may in part due to the improvement of the measure of the pregnant women cohort that exposed to influenza season

27. Recommendations
We achieved relatively higher vaccination coverage among pregnant women for the season, however it is still well below Healthy People 2020 goal of 90%, so
Continued effort should be made to effectively deliver the message to pregnant women about the safety and effectiveness of the vaccines and the risk of flu to both themselves and their babies.
The newly developed partnership with provider communities need to be strengthened to maintain and increase vaccination coverage among pregnant women.

28. Questions? Thanks! Helen Ding Hding@cdc.gov

29. Extra slides

30. Sample size Women 18-49 yrs Sample size Wgt'd % Total women 18-49 yrs
Sample size
Wgt'd %
Total women yrs
3,839
100%
Pregnant women
244 6%
with HRC 50
Without HRC
194
Non-pregnant with HRC
832
21%
Non-pregnant without HRC
2,763
73%

32. High-risk conditions: Influenza vaccination coverage among pregnant women-NHFS-2009-10 season

33. Education: Influenza vaccination coverage among pregnant women NHFS 2009-10 season%

34. Race/ethnicity: Influenza vaccination coverage among pregnant women NHFS 2009-10 season

35. Doctor’s recommendation: Influenza vaccination coverage among three groups of women

37. Influenza vaccination among three groups of women

38. Commentary (cont’)
During the season new partnerships in the provider community serving pregnant women were developed.
Extensive vaccination campaign and outreach efforts were conducted toward care providers for pregnant women through such partnerships to assure patient vaccination.
Tailored communication messages based on focus groups conducted among pregnant women were utilized to develop posters and flyers.
More accurate coverage measures were utilized such as asking women who were pregnant during the season about their vaccination during the season.

39. Limitations
Sample size was relative small, which limited the abilities to run the multivariable model for pregnant women only
Still we were not sure whether the vaccination was given before, during or after the pregnancy, though the vaccination period and the pregnancy period coincided

40. Attitudes toward influenza vaccination among pregnant women

41. Historically vaccination coverage repor