1895. Impact of PCV7 and PCV13 on the Serotype Distribution of Invasive Pneumococcal Disease in Adults in Kansas City
Session: Poster Abstract Session: Vaccines: PCV
Saturday, October 10, 2015
Room: Poster Hall
  • 2015 IDWeek Adult Serotype IPD Kansas.pdf (514.4 kB)
  • Background: Routine pediatric pneumococcal conjugate vaccine (PCV7) use reduced IPD due to PCV7 types in both vaccinated children and unvaccinated adults. We examined the seroepidemiology of adult IPD in metropolitan Kansas City, KS pre- and post-PCV13 release.

    Methods: To assess the impact of PCV13 on adult IPD, we compared serotypes and patient risk factors in 2003-2006 (pre-PCV13) and 2010-2013 (post PCV13). We analyzed demographic/clinical data, serotypes, and antimicrobial susceptibility.

    Results: A total of 116 pneumococcal isolates were serotyped. IPD due to PCV7-only serotypes significantly decreased. Of 16 PCV7-only isolates, 13 (35%) were seen in 2003-2006, vs. 3 (4%) in 2010-2013 (p<0.0001). PCV13-related adult IPD cases decreased somewhat in 2010-13. Of the 57 PCV13-related isolates, 23 (63%) were seen in 2003-2006 vs. 34 (43%) in 2010-2013 (p=0.07). A larger proportion of isolates were nonvaccine serotypes (N-VT) post-PCV13. (Table)

    Serotype Distribution

    N (% of column)





    P value per row






    PCV7 only

    16 (14%)

    13 (35%)

    3 (4%)

    p <0.0001


    57 (49%)

    23 (62%)

    34 (43%)

    p = 0.07


    59 (51%)

    14 (37%)

    45 (57%)

    p = 0.07

    In 2003-2006, 29 (78%) of isolates were penicillin-susceptible vs.  61 (77%) in 2010-2013 (NS). Serotype prevalence for select serotypes increased in 2010-13 (7F from 8% to 16%; 19A from 5% to 12%). The median ages and risk factors for IPD did not change significantly between study periods.  

    Conclusion: A significant decline in PCV7-type IPD was observed. The decline in IPD cases related to the added 6 types in PCV13 declined, but did not reach statistical significance. This may indicate that herd immunity requires a longer post-PCV13 period of time to significantly reduce IPD in any one region. Continued surveillance of the seroepidemiology of adult IPD is warranted as direct PCV13 adult immunization is expanded.

    Fernando Merino, MD, Infectious Diseases, University of Kansas Medical Center, Kansas City, KS, Erin Atwood, BS, University of Kansas School of Medicine, Kansas City, KS, Rebecca Horvat, PhD, Pathology and Laboratory Medicine, University of Kansas, Kansas City, KS, Douglas Swanson, MD, Children's Mercy Hospital & UMKC School of Medicine, Kansas City, MO, Christopher Harrison, M.D., FSHEA, FPIDS, Pediatrics, Children's Mercy Hospitals and Clinics, Kansas City, MO, R. Scott Duncan, Ph.D., Infectious Diseases, Children's Mercy Hospital, Kansas City, MO, Maria J Tort, PhD, Pfizer Inc, Collegeville, PA and Angee Mcdaniel, PharmD, Pfizer, Inc., Collegeville, PA


    F. Merino, Pfizer: Grant Investigator , Research grant

    E. Atwood, None

    R. Horvat, IBT Laboratory: Consultant and Speaker's Bureau , Consulting fee

    D. Swanson, Pfizer Inc: Grant Investigator , Research grant

    C. Harrison, Pfizer: Grant Investigator , Research support
    Actavis: Grant Investigator , Research grant
    GSK: Grant Investigator , Research grant

    R. S. Duncan, Pfizer: Investigator , Research grant

    M. J. Tort, Pfizer: Employee , Salary

    A. Mcdaniel, Pfizer: Employee , Salary

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