871. Safety of the 2009 H1N1 Influenza Vaccine in Pregnant Women
Session: Abstracts: Oral Abstract Session: Influenza Vaccination: Safety and Policy; Health Care Workers
Saturday, October 23, 2010: 11:30 AM
118-120

Background:

Pregnant women were a top priority to receive the 2009 H1N1 influenza vaccine due to the high rate of complications after influenza infection in that population. We conducted an observational, longitudinal study of pregnant women to assess short-term adverse events after H1N1 vaccination.

Methods:

Women were recruited over four months at two sites and enrolled just before or after a prenatal visit.  Eligibility criteria included: age ≥18 years old, <38 weeks gestation, and no prior H1N1 vaccination. Participants chose to receive H1N1 vaccine only, seasonal influenza vaccine only, both seasonal and H1N1 vaccines, or no vaccine. Women recorded temperatures for ≥7 days and symptoms (headache, nausea, muscle aches, chills, diarrhea, rash, sore arm) for 14 days after enrollment; symptom severity was scored as 0 (absent), 1 (mild), 2 (moderate), or 3 (severe).

Results:

Of 717 participants, 33% received H1N1 vaccine, seasonal vaccine, or both.  Of the women vaccinated, 77% received H1N1 vaccine only (Group 1), 18% received both H1N1 and seasonal vaccine (Group 2), and 5% received seasonal vaccine only (Group 3). The mean temperature was similar for vaccinated (97.4˚F) and unvaccinated (97.3˚F) women, and between Groups 1-3 of vaccinated women; only 1 vaccinated woman had a temperature ≥100˚F.  At least one symptom was reported by 85% of the vaccinated; the most frequent symptoms were sore arm (66%), headache (61%), nausea (47%), and muscle aches (31%).  The overall mean symptom severity score was 0.76 in vaccinated and 0.71 in unvaccinated women. Among the vaccinated, the mean severity score was 0.76 for Group 1, 0.70 for Group 2, and 1.06 for Group 3.  Except for arm soreness, the mean severity scores for specific symptoms were similar between the vaccinated and unvaccinated.

Conclusion:

Pregnant women who received the 2009 H1N1 vaccine were not substantially more likely than non-vaccinated women to report fever or short-term side effects (except for arm soreness).  The short-term adverse effects of the 2009 H1N1 vaccine were minimal.


Subject Category: I. Adult and Pediatric Vaccines

Speakers:
James Donahue, PhD , Epidemiology, Marshfield Clinic Research Foundation, Marshfield, WI
Allison Naleway, PhD , Kaiser Permanente- Northwest, Portland, OR
Michelle Henninger, PhD , Kaiser Permanente- Northwest, Portland, OR
Stephanie Irving, MHS , Epidemiology Research Center, Marshfield Clinic Research Foundation, Marshfield, WI
Burney Kieke, MS , Epidemiology Research Center, Marshfield Clinic Research Foundation, Marshfield, WI
Bradley Crane, MS , Kaiser Permanente- Northwest, Portland, OR
Deanna Cole , Epidemiology, Marshfield Clinic Research Foundation, Marshfield, WI
Eric Weintraub, MPH , Immunization Safety Office, Centers for Disease Control and Prevention, Atlanta, GA
Edward Belongia, MD , Marshfield Clinic Research Foundation, Marshfield, WI

Disclosures:

J. Donahue, None

A. Naleway, None

M. Henninger, None

S. Irving, None

B. Kieke, None

B. Crane, None

D. Cole, None

E. Weintraub, None

E. Belongia, None


Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 21 with the exception of research findings presented at IDSA press conferences.

 
 
   
 

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