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Dive into the research topics where Ryan Gierke is active.

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Featured researches published by Ryan Gierke.


Morbidity and Mortality Weekly Report | 2015

Intervals Between PCV13 and PPSV23 Vaccines: Recommendations of the Advisory Committee on Immunization Practices (ACIP).

Miwako Kobayashi; Nancy M. Bennett; Ryan Gierke; Olivia M. Almendares; Matthew R. Moore; Cynthia G. Whitney; Tamara Pilishvili

Two pneumococcal vaccines are currently licensed for use in the United States: the 13-valent pneumococcal conjugate vaccine (PCV13 [Prevnar 13, Wyeth Pharmaceuticals, Inc., a subsidiary of Pfizer Inc.]) and the 23-valent pneumococcal polysaccharide vaccine (PPSV23 [Pneumovax 23, Merck and Co., Inc.]). The Advisory Committee on Immunization Practices (ACIP) currently recommends that a dose of PCV13 be followed by a dose of PPSV23 in all adults aged ≥65 years who have not previously received pneumococcal vaccine and in persons aged ≥2 years who are at high risk for pneumococcal disease because of underlying medical conditions (Table) (1-4). The recommended intervals between PCV13 and PPSV23 given in series differ by age and risk group and the order in which the two vaccines are given (1-4).


Journal of General Internal Medicine | 2016

Incremental Cost-Effectiveness of 13-valent Pneumococcal Conjugate Vaccine for Adults Age 50 Years and Older in the United States

Charles Stoecker; Lindsay Kim; Ryan Gierke; Tamara Pilishvili

ABSTRACTBACKGROUNDRecently released results from a randomized controlled trial have shown that 13-valent pneumococcal conjugate vaccine (PCV13) is efficacious against vaccine-type nonbacteremic pneumonia in adults.OBJECTIVEWe examined the incremental cost-effectiveness of adding PCV13 to the Advisory Committee on Immunization Practices (ACIP) adult immunization schedule.METHODSWe used a probabilistic model following cohorts of 50-, 60-, or 65-year-olds. We used separate vaccination coverage and disease incidence data for healthy and high-risk adults. Incremental cost-effectiveness ratios were determined for each potential vaccination strategy.RESULTSIn the base case scenario, our model indicated that adding PCV13 at age 65 or replacing 23-valent pneumococcal polysaccharide vaccine (PPSV23) at age 65 with PCV13 provided more value for money than adding PCV13 at ages 50 or 60. After projections of six additional years of herd protection from the childhood immunization program were incorporated, we found adding PCV13 dominated replacing PPSV23. For a cohort of 65-year-olds in 2013, the cost of adding PCV13 at age 65 to the schedule was


Clinical Infectious Diseases | 2016

Prevention of Antibiotic-Nonsusceptible Invasive Pneumococcal Disease With the 13-Valent Pneumococcal Conjugate Vaccine

Sara Tomczyk; Ruth Lynfield; William Schaffner; Arthur Reingold; Lisa Miller; Susan Petit; Corinne Holtzman; Shelly Zansky; Ann Thomas; Joan Baumbach; Lee H. Harrison; Monica M. Farley; Bernard Beall; Lesley McGee; Ryan Gierke; Tracy Pondo; Lindsay Kim

62,065 per quality-adjusted life year (QALY) gained, which rose to


Clinical Infectious Diseases | 2016

Multistate Outbreak of Respiratory Infections Among Unaccompanied Children, June 2014–July 2014

Sara Tomczyk; Carmen S. Arriola; Bernard Beall; Alvaro J. Benitez; Stephen R. Benoit; LaShondra Berman; Joseph S. Bresee; Maria da Gloria Carvalho; Amanda C. Cohn; Kristen E. Cross; Maureen H. Diaz; Louise Francois Watkins; Ryan Gierke; José E. Hagan; Aaron M. Harris; Seema Jain; Lindsay Kim; Miwako Kobayashi; Stephen Lindstrom; Lesley McGee; Meredith McMorrow; Benjamin L. Metcalf; Matthew R. Moore; Iaci N. S. Moura; W. Allan Nix; Edith Nyangoma; M. Steven Oberste; Sonja J. Olsen; Fabiana Cristina Pimenta; Christina Socias

272,621 after 6 years of projected herd protection.CONCLUSIONThe addition of one dose of PCV13 for adults appears to have a cost-effectiveness ratio comparable to other vaccination interventions in the short run, though anticipated herd protection from the childhood immunization program may dramatically increase the cost per QALY after only a few years.


Emerging Infectious Diseases | 2017

Penicillin Resistance of Nonvaccine Type Pneumococcus before and after PCV13 Introduction, United States

Cheryl P. Andam; Colin J. Worby; Ryan Gierke; Lesley McGee; Tamara Pilishvili; William P. Hanage

BACKGROUND Antibiotic-nonsusceptible invasive pneumococcal disease (IPD) decreased substantially after the US introduction of the pediatric 7-valent pneumococcal conjugate vaccine (PCV7) in 2000. However, rates of antibiotic-nonsusceptible non-PCV7-type IPD increased during 2004-2009. In 2010, the 13-valent pneumococcal conjugate vaccine (PCV13) replaced PCV7. We assessed the impact of PCV13 on antibiotic-nonsusceptible IPD rates. METHODS We defined IPD as pneumococcal isolation from a normally sterile site in a resident from 10 US surveillance sites. Antibiotic-nonsusceptible isolates were those intermediate or resistant to ≥1 antibiotic classes according to 2012 Clinical and Laboratory Standards Institute breakpoints. We examined rates of antibiotic nonsusceptibility and estimated cases prevented between observed cases of antibiotic-nonsusceptible IPD and cases that would have occurred if PCV13 had not been introduced. RESULTS From 2009 to 2013, rates of antibiotic-nonsusceptible IPD caused by serotypes included in PCV13 but not in PCV7 decreased from 6.5 to 0.5 per 100 000 in children aged <5 years and from 4.4 to 1.4 per 100 000 in adults aged ≥65 years. During 2010-2013, we estimated that 1636 and 1327 cases of antibiotic-nonsusceptible IPD caused by serotypes included in PCV13 but not PCV7 were prevented among children aged <5 years (-97% difference) and among adults aged ≥65 years (-64% difference), respectively. Although we observed small increases in antibiotic-nonsusceptible IPD caused by non-PCV13 serotypes, no non-PCV13 serotype dominated among antibiotic-nonsusceptible strains. CONCLUSIONS After PCV13 introduction, antibiotic-nonsusceptible IPD decreased in multiple age groups. Continued surveillance is needed to monitor trends of nonvaccine serotypes. Pneumococcal conjugate vaccines are important tools in the approach to combat antibiotic resistance.


Pediatric Infectious Disease Journal | 2017

PNEUMOCOCCAL SEROTYPE 5 COLONIZATION PREVALENCE AMONG NEWLY ARRIVED UNACCOMPANIED CHILDREN 1 YEAR AFTER AN OUTBREAK—TEXAS, 2015

Miwako Kobayashi; Lara Misegades; Katherine E. Fleming-Dutra; Sana Ahmed; Ryan Gierke; Srinivas Nanduri; Jessica M. Healy; Duong T. Nguyen; Maria da Gloria Carvalho; Fabiana Cristina Pimenta; Stephen H. Waterman; Matthew R. Moore; Curi Kim; Cynthia G. Whitney

BACKGROUND From January 2014-July 2014, more than 46 000 unaccompanied children (UC) from Central America crossed the US-Mexico border. In June-July, UC aged 9-17 years in 4 shelters and 1 processing center in 4 states were hospitalized with acute respiratory illness. We conducted a multistate investigation to interrupt disease transmission. METHODS Medical charts were abstracted for hospitalized UC. Nonhospitalized UC with influenza-like illness were interviewed, and nasopharyngeal and oropharyngeal swabs were collected to detect respiratory pathogens. Nasopharyngeal swabs were used to assess pneumococcal colonization in symptomatic and asymptomatic UC. Pneumococcal blood isolates from hospitalized UC and nasopharyngeal isolates were characterized by serotyping and whole-genome sequencing. RESULTS Among 15 hospitalized UC, 4 (44%) of 9 tested positive for influenza viruses, and 6 (43%) of 14 with blood cultures grew pneumococcus, all serotype 5. Among 48 nonhospitalized children with influenza-like illness, 1 or more respiratory pathogens were identified in 46 (96%). Among 774 nonhospitalized UC, 185 (24%) yielded pneumococcus, and 70 (38%) were serotype 5. UC transferring through the processing center were more likely to be colonized with serotype 5 (odds ratio, 3.8; 95% confidence interval, 2.1-6.9). Analysis of core pneumococcal genomes detected 2 related, yet independent, clusters. No pneumococcus cases were reported after pneumococcal and influenza immunization campaigns. CONCLUSIONS This respiratory disease outbreak was due to multiple pathogens, including Streptococcus pneumoniae serotype 5 and influenza viruses. Pneumococcal and influenza vaccinations prevented further transmission. Future efforts to prevent similar outbreaks will benefit from use of both vaccines.


Open Forum Infectious Diseases | 2017

Changes in invasive pneumococcal disease among adults living with HIV following introduction of 13-valent pneumococcal conjugate vaccine, 2008–2014

Miwako Kobayashi; William K. Adih; Jianmin Li; Ryan Gierke; Olivia M. Almendares; James Watt; Nisha Alden; Susan Petit; Monica M. Farley; Lee H. Harrison; Ruth Lynfield; Joan Baumbach; Ann Thomas; William Schaffner; Tamara Pilishvili

Introduction of 13-valent pneumococcal conjugate vaccine in the United States was not associated with a significant change in prevalence of penicillin resistance in nonvaccine type serotypes because of the variable success of highly resistant serotypes. Differences in regional serotype distribution and serotype-specific resistance contributed to geographic heterogeneity of penicillin resistance.


Journal of Vaccines and Vaccination | 2017

Simplified Pneumococcal Vaccination Schedules for Adults Age 50 and Over Lead to Worse Health

Charles Stoecker; Lindsay Kim; Ryan Gierke; Tamara Pilishvili

In 2014, an acute respiratory illness outbreak affected unaccompanied children from Central America entering the United States; 9% of 774 surveyed children were colonized with Streptococcus pneumoniae serotype 5. In our 2015 follow-up survey of 475 children, serotype 5 was not detected, and an interim recommendation to administer 13-valent pneumococcal conjugate vaccine to all unaccompanied children was discontinued.


Morbidity and Mortality Weekly Report | 2014

Use of 13-valent pneumococcal conjugate vaccine and 23-valent pneumococcal polysaccharide vaccine among adults aged ≥65 years: recommendations of the Advisory Committee on Immunization Practices (ACIP).

Tomczyk S; Nancy M. Bennett; Stoecker C; Ryan Gierke; Moore Mr; Cynthia G. Whitney; Hadler S; Tamara Pilishvili

Abstract Background People living with HIV (PLHIV) are at increased risk of invasive pneumococcal disease (IPD). Introduction of 13-valent pneumococcal conjugate vaccine (PCV13) in children in 2010 reduced adult IPD burden (indirect effects). In 2012, PCV13 was recommended in series with 23-valent polysaccharide vaccine (PPSV23) for adults with immunocompromising conditions, including PLHIV. We evaluated changes in IPD incidence in adults ≥19 years old with and without HIV after PCV13 introduction for children in 2010 and for immunocompromised adults in 2012. PCV13 coverage for adults 19–64 years old with indications was 6% in 2014. Methods IPD cases, defined as pneumococcal isolation from sterile sites, were identified through CDC’s Active Bacterial Core surveillance, with counts projected nationally. HIV status was obtained from medical records. Isolates were serotyped by Quellung reaction or PCR and grouped into PCV13-types, PPV11-types (unique to PPSV23), or non-vaccine types. We estimated IPD incidence (cases per 100,000 people) using national case-based HIV surveillance (for PLHIV) or US Census data (for non-PLHIV) as denominators. We compared IPD incidence in 2011–12 and 2013–14 to the pre-PCV13 baseline (2008–09) by serotype groups. Results Overall IPD incidence at baseline was 354.0 for PLHIV and 15.5 for non-PLHIV. From baseline to 2013–14, IPD rates declined in both PLHIV (-36.3%; 95% CI: -38.8, -33.7%) and non-PLHIV (-27.3%; 95% CI: -28.2, -26.5%). The largest reductions were noted in PCV13-type IPD in both PLHIV (Figure 1) and non-PLHIV (Figure 2) for both periods (-46.8% for PLHIV and -45.9% for non-PLHIV in 2011–12; -60.3% for PLHIV and -65.8% for non-PLHIV in 2013–14). Overall IPD rates were 22.8 (95% CI: 22.2, 23.4) times as high in PLHIV compared with non-PLHIV at baseline, and 19.4 (95% CI: 18.8, 20.0) times as high in 2013–2014. Conclusion IPD rates declined significantly in both PLHIV and non-PLHIV during the study period due to reductions in PCV13-type IPD; however, IPD rates remained 20-fold in PLHIV compared with non-PLHIV. Similar magnitude reductions in PCV13-type IPD in both groups and low PCV13 coverage in immunocompromised adults suggest that most of the observed decline is due to PCV13 indirect effects from childhood immunization. Disclosures L. Harrison, GSK: Scientific Advisor, Consulting fee; W. Schaffner, Pfizer: Scientific Advisor, Consulting fee; Merck: Scientific Advisor, Consulting fee; Novavax: Consultant, Consulting fee; Dynavax: Consultant, Consulting fee; Sanofi-pasteur: Consultant, Consulting fee; GSK: Consultant, Consulting fee; Seqirus: Consultant, Consulting fee


Archive | 2013

Use of 13-Valent Pneumococcal Conjugate Vaccine and 23-Valent Pneumococcal Polysaccharide Vaccine Among Children Aged 6–18 Years with Immunocompromising Conditions: Recommendations of the Advisory Committee on Immunization Practices (ACIP)

Nancy M. Bennett; Tamara Pilishvili; Cynthia G. Whitney; Matthew R. Moore; Ryan Gierke; Aaron M. Harris

Background: In 2014 the Advisory Committee on Immunization Practices (ACIP) approved a dose of 13-valent pneumococcal conjugate vaccine (PCV13) for all adults at age 65 years. This further complicated the pneumococcal vaccination schedule, which was already one of the most complicated schedules. Objective: This study documents simplified schedules that were considered and discarded by the pneumococcal working group before making the most recent recommendation. We examined the marginal cost-effectiveness of several simplified schedules for older adults (age 50+ years) when compared with current recommendations. Our primary outcome was the cost-effectiveness ratio of quality-adjusted life years to cost. Methods: We used a probabilistic model following a cohort of 50 year-olds with separate vaccination coverage and disease incidence data for healthy adults and adults at increased risk of pneumococcal disease. We compared incremental cost-effectiveness ratios from the schedule that was ultimately recommended with each potential simplified vaccination strategy. Results: Most schedules analyzed resulted in several hundred additional deaths. While several possible schedules resulted in cost savings, these cost savings were modest compared to the health costs associated with them. Conclusion: The schedule recommended by the ACIP in 2014, while complex, is the most health promoting compared to the modeled alternative schedules. The incremental cost-effectiveness ratio of the current schedule when compared to simplified alternatives is comparable to other vaccine-related interventions.

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Tamara Pilishvili

Centers for Disease Control and Prevention

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Lindsay Kim

Centers for Disease Control and Prevention

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Cynthia G. Whitney

Centers for Disease Control and Prevention

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Matthew R. Moore

Centers for Disease Control and Prevention

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Miwako Kobayashi

Centers for Disease Control and Prevention

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Lesley McGee

Centers for Disease Control and Prevention

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Ann Thomas

Brigham and Women's Hospital

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Bernard Beall

National Center for Immunization and Respiratory Diseases

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