154. Acute Demyelinating Events Following Immunization
Session: Poster Abstract Session: Adult and Pediatric Vaccines
Thursday, October 3, 2013
Room: The Moscone Center: Poster Hall C
  • IDSA ADE poster final.pdf (339.7 kB)
  • Background: Amid concerns that vaccines might trigger autoimmunity, there is a need to study acute demyelinating events (ADEs) as possible adverse events following immunization.

    Methods: Using data from electronic medical records at Kaiser Permanente Northern California from 2007 through 2012, we identified incident cases of Optic Neuritis (ON), Transverse Myelitis (TM), Acute Disseminated Encephalomyelitis (ADEM), and other myelitis that occurred within 9 months of any type of vaccination. There were 16 types of vaccine that were received within 9 months prior to an ADE. To examine each possible association of one of the four types of outcomes with one of the 16 types of vaccine, we identified a risk set for each outcome event, comprised of all Kaiser members who were in the same age-sex group and were vaccinated within 9 months of the diagnosis date. We compared the observed odds that ADE cases were diagnosed in a risk interval with the odds expected from their risk sets. The primary risk interval, 5-28 days before diagnosis, was specified in advance in consultation with experts and compared with the rest of the 9-month pre-diagnosis period; a secondary risk interval 2-42 days before diagnosis was also assessed. We used logistic regression to estimate odds ratios, confidence intervals, and hypothesis tests (2-sided alpha=0.05).  Only principal inpatient and emergency diagnoses were used to identify ADEM, TM and myelitis; outpatient diagnoses were also used for ON.

    Results: During the primary risk interval, which included 24 (8.8%) of the days in the 9 months observed for each vaccinee, there were 41 (6.7%) of the 612 cases of ON, 1 (0.7%) of the 149 cases of myelitis, and none of the 53 cases of TM and 28 cases of ADEM.   In the adjusted analysis stratified by risk sets, there was no significant evidence of increased risk of any of the 4 outcomes during either the primary or secondary risk interval after any type of vaccine.

    Conclusion: In a population given 18.2 million vaccinations over six years, there was no evidence of any increased risk of four types of acute demyelinating disease after any type of vaccine.

    Roger Baxter, MD1, Edwin Lewis, MPH1, Bruce Fireman, MA1, Julia Mcdonald, MS, MPH1, Shahed Iqbal, PhD, MBBS, MPH2, Frank Destefano, MD, MPH2, Claudia Vellozzi, MD2 and Nicola P. Klein, MD, PhD1, (1)Kaiser Permanente Vaccine Study Center, Oakland, CA, (2)Centers for Disease Control and Prevention, Atlanta, GA


    R. Baxter, Pfizer: Grant Investigator, Grant recipient
    Merck & Co.: Grant Investigator, Research grant
    GlaxoSmithKline: Grant Investigator, Research grant
    Sanofi Pasteur: Grant Investigator, Research grant
    MedImmune: Grant Investigator, Research grant
    Novartis: Grant Investigator, Research grant
    Protein Sciences: Grant Investigator, Research grant

    E. Lewis, None

    B. Fireman, None

    J. Mcdonald, None

    S. Iqbal, None

    F. Destefano, None

    C. Vellozzi, None

    N. P. Klein, Merck & Co: Grant Investigator, Research grant
    GlaxoSmithKline: Grant Investigator, Research grant
    sanofi pasteur: Grant Investigator, Research grant
    Novartis: Grant Investigator, Research grant
    Protein Science: Grant Investigator, Grant recipient
    Pfizer: Grant Investigator, Research grant

    Findings in the abstracts are embargoed until 12:01 a.m. PST, Oct. 2nd with the exception of research findings presented at the IDWeek press conferences.