798. Lack of risk for Aseptic Meningitis after Childhood Immunization: A Case-Centered Analysis
Session: Poster Abstract Session: Vaccines: Safety and Adverse Events
Thursday, October 27, 2016
Room: Poster Hall
Posters
  • ID Week Poster 798.pdf (350.9 kB)
  • BackgroundCase reports of aseptic meningitis (AM) following vaccination in infants and young children have led to concerns that vaccines may rarely be the cause. Due to this concern, we analyzed for an association between aseptic meningitis and childhood vaccines.

    Methods: We identified cases in children aged 8 years and younger by searching Kaiser Permanente Northern California (KPNC) databases from 2007-2014 for all first time AM diagnoses occurring within 9 months of any immunization. We selected exposure intervals of 1-7 and 1-28 days prior to AM diagnoses based on case reports and biologic plausibility. We reviewed all potential cases within 4 weeks of any immunization to verify the diagnosis and onset date.

    Using a case-centered study design, we compared the proportion of cases recently vaccinated (1-7 and 1-28 days prior) with an expected proportion derived from all age-sex matched KPNC members on the anchor onset date for each case (i.e., date AM case began). We included all matched KPNC members who were vaccinated in the 9 months prior to the anchoring onset date. We repeated the analysis for each vaccine type and for "any vaccine" separately using electronic data and using chart confirmed cases only. In addition, we computed risk difference (excess risk) estimates.

    Results: During the study period >10 million vaccines were administered at KPNC within the study population. We identified 28 cases immunized during the prior 4 weeks, of which 25 (89%) were confirmed as AM. In the 1-7 day and 1-28 day exposure intervals we found no statistically significant increased risk of immunization compared with matched controls for any vaccine. The risk difference for “any” immunization and AM per one million doses of vaccine was 0.014 (95% CI -0.93, 1.50) for the 1-7 day exposure interval and -0.444 (95% CI -2.38, 1.97) for the 1-28 day exposure interval. Results for analyses using electronic data only were similar.

    Conclusion: Our large-scale analysis applying a case-centered method did not detect any statistically significant association between cases of AM and previous receipt of any childhood vaccine. If a risk for AM following any vaccine does exist, the risk is less than 2 in 1 million doses.

    Kristin Goddard, MPH, Ned Lewis, MPH, Roger Baxter, MD, FIDSA and Nicola P. Klein, MD, PhD, Kaiser Permanente Vaccine Study Center, Oakland, CA

    Disclosures:

    K. Goddard, None

    N. Lewis, None

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

    N. P. Klein, GlaxoSmithKline: Grant Investigator , Research grant
    Merck & Co: Grant Investigator , Research grant
    Pfizer: Grant Investigator , Research grant
    Sanofi Pasteur: Grant Investigator , Research grant
    MedImmune: Grant Investigator , Research grant
    Novartis (now GSK): Grant Investigator , Research grant
    Protein Science: Grant Investigator , Research grant

    Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.