Featured Publications
Pneumococcal infections in children with sickle cell disease before and after pneumococcal conjugate vaccines
Adamkiewicz T, Yee M, Thomas S, Tunali A, Lai K, Omole F, Lane P, Yildirim I. Pneumococcal infections in children with sickle cell disease before and after pneumococcal conjugate vaccines. Blood Advances 2023, 7: 6751-6761. PMID: 37698500, PMCID: PMC10660014, DOI: 10.1182/bloodadvances.2022009643.Peer-Reviewed Original ResearchConceptsInvasive pneumococcal diseaseSickle cell diseaseCell diseasePCV13-serotype invasive pneumococcal diseaseSerotype invasive pneumococcal diseaseNon-PCV13 serotypesPneumococcal polysaccharide vaccinePneumococcal conjugate vaccineIncidence rate ratiosYears of vaccinationReference populationLife-threatening risksIPD episodesIPD serotypesPneumococcal diseasePneumococcal infectionPolysaccharide vaccineConjugate vaccineHemoglobin SSVaccine licensureEffective vaccinePenicillin resistanceDisease controlVaccineAfrican American childrenInvasive Pneumococcal Disease After 2 Decades of Pneumococcal Conjugate Vaccine Use.
Yildirim I, Lapidot R, Shaik-Dasthagirisaheb Y, Hinderstein S, Lee H, Klevens M, Grant L, Arguedas Mohs A, Cane A, Madoff L, Johnson H, Ivanof C, Burns M, Pelton S. Invasive Pneumococcal Disease After 2 Decades of Pneumococcal Conjugate Vaccine Use. Pediatrics 2023, 153 PMID: 38087952, DOI: 10.1542/peds.2023-063039.Peer-Reviewed Original ResearchConceptsInvasive pneumococcal diseaseIPD casesPCV13 eraPneumococcal diseaseCases of IPDIncidence of IPDRates of IPDPneumococcal conjugate vaccine useSerotype 15B/CImplementation of PCV13Non-PCV13 serotypesPneumococcal conjugate vaccineConfidence intervalsStatewide surveillance systemIPD incidence ratesIPD ratesPenicillin nonsusceptibilityConjugate vaccineVaccine serotypesSerotype 19ASterile sitesIncidence rateVaccine useLower incidenceVaccine formulations
2024
Immunogenicity of Current and Next-Generation Pneumococcal Conjugate Vaccines in Children: Current Challenges and Upcoming Opportunities
Feemster K, Buchwald U, Banniettis N, Joyce J, Velentgas P, Chapman T, Yildirim I. Immunogenicity of Current and Next-Generation Pneumococcal Conjugate Vaccines in Children: Current Challenges and Upcoming Opportunities. Open Forum Infectious Diseases 2024, 11: ofae220. PMID: 38770212, PMCID: PMC11103622, DOI: 10.1093/ofid/ofae220.Peer-Reviewed Original Research
2021
Changes in Invasive Pneumococcal Disease Caused by Streptococcus pneumoniae Serotype 1 following Introduction of PCV10 and PCV13: Findings from the PSERENADE Project
Bennett JC, Hetrich MK, Garcia Quesada M, Sinkevitch JN, Deloria Knoll M, Feikin DR, Zeger SL, Kagucia EW, Cohen AL, Ampofo K, Brandileone MC, Bruden D, Camilli R, Castilla J, Chan G, Cook H, Cornick JE, Dagan R, Dalby T, Danis K, de Miguel S, De Wals P, Desmet S, Georgakopoulou T, Gilkison C, Grgic-Vitek M, Hammitt LL, Hilty M, Ho PL, Jayasinghe S, Kellner JD, Kleynhans J, Knol MJ, Kozakova J, Kristinsson KG, Ladhani SN, MacDonald L, Mackenzie GA, Mad’arová L, McGeer A, Mereckiene J, Morfeldt E, Mungun T, Muñoz-Almagro C, Nuorti JP, Paragi M, Pilishvili T, Puentes R, Saha SK, Sahu Khan A, Savrasova L, Scott JA, Skoczyńska A, Suga S, van der Linden M, Verani JR, von Gottberg A, Winje BA, Yildirim I, Zerouali K, Hayford K, . Changes in Invasive Pneumococcal Disease Caused by Streptococcus pneumoniae Serotype 1 following Introduction of PCV10 and PCV13: Findings from the PSERENADE Project. Microorganisms 2021, 9: 696. PMID: 33801760, PMCID: PMC8066231, DOI: 10.3390/microorganisms9040696.Peer-Reviewed Original ResearchInvasive pneumococcal diseasePneumococcal conjugate vaccinePneumococcal diseaseIncidence rateSerotype 1Streptococcus pneumoniae serotype 1Mixed-effects Poisson regressionInfant immunization programIntroduction of PCV10Pneumococcal serotype replacementIncidence rate ratiosIPD surveillance dataYears of ageIPD incidenceSerotype replacementLinear mixed-effects regressionConjugate vaccineBurden countriesImmunization programsMixed-effects regressionImportant causePoisson regressionSurveillance dataRate ratioPCV10/13
2020
Recognition and Outcomes of Pneumococcal Meningitis in 2 Tertiary Pediatric Hospitals Since the Introduction of the 13-Valent Pneumococcal Conjugate Vaccine
Stevens JP, Lively A, Jerris R, Yildirim I, Lantis P. Recognition and Outcomes of Pneumococcal Meningitis in 2 Tertiary Pediatric Hospitals Since the Introduction of the 13-Valent Pneumococcal Conjugate Vaccine. Pediatric Emergency Care 2020, 38: e354-e359. PMID: 33181795, DOI: 10.1097/pec.0000000000002288.Peer-Reviewed Original ResearchConceptsPneumococcal conjugate vaccineLumbar puncturePneumococcal meningitisConjugate vaccineMeningeal signsLow suspicionMental statusPositive cerebrospinal fluid culturesLonger hospital lengthStreptococcus pneumoniae meningitisCerebrospinal fluid culturesCranial nerve palsyHours of admissionTertiary pediatric hospitalPoor clinical outcomeTertiary healthcare systemPneumococcal meningitis casesPneumococcal immunizationPneumoniae meningitisHospital lengthNerve palsyPrimary outcomeAntibiotic administrationClinical outcomesPediatric hospitalCharacteristics of Serotype 3 Invasive Pneumococcal Disease before and after Universal Childhood Immunization with PCV13 in Massachusetts
Lapidot R, Shea KM, Yildirim I, Cabral HJ, Pelton SI, Health T. Characteristics of Serotype 3 Invasive Pneumococcal Disease before and after Universal Childhood Immunization with PCV13 in Massachusetts. Pathogens 2020, 9: 396. PMID: 32455770, PMCID: PMC7281000, DOI: 10.3390/pathogens9050396.Peer-Reviewed Original ResearchPneumococcal conjugate vaccineIPD casesIncidence rate ratiosIPD incidencePCV-13Disease characteristicsSerotype 3 invasive pneumococcal diseaseInvasive pneumococcal disease incidenceImpact of PCV13Presence of comorbiditiesInvasive pneumococcal diseasePneumococcal disease incidenceUniversal childhood immunizationWaning of immunityPassive surveillance systemPCV13 dosePCV13 introductionVaccine effectivenessConjugate vaccineMassachusetts childrenPneumococcal diseaseClinical syndromeChildhood immunizationIncidence ratePCV13Who is at risk of 13-valent conjugated pneumococcal vaccine failure?
Yildirim M, Keskinocak P, Pelton S, Pickering L, Yildirim I. Who is at risk of 13-valent conjugated pneumococcal vaccine failure? Vaccine 2020, 38: 1671-1677. PMID: 31974018, DOI: 10.1016/j.vaccine.2019.12.060.Peer-Reviewed Original ResearchConceptsInvasive pneumococcal diseaseVaccine failureIPD casesVaccine serotypesDiagnosis of IPDHigh vaccine coverage ratesPneumococcal conjugate vaccineVaccine coverage ratesUnderlying risk factorsYears of ageMonths of agePneumococcal pneumoniaImmunization PracticesVaccine scheduleConjugate vaccinePneumococcal diseasePrimary dosesClinical presentationImmunization scheduleSerotype 19ACourse of immunisationRisk factorsComorbiditiesStudy periodPassive surveillance
2018
1430. Evolving Impact of 13-Valent Pneumococcal Conjugate Vaccine on Invasive Pneumococcal Disease
Yildirim I, Little B, Shea K, Pelton S, Massachusetts M. 1430. Evolving Impact of 13-Valent Pneumococcal Conjugate Vaccine on Invasive Pneumococcal Disease. Open Forum Infectious Diseases 2018, 5: s441-s442. PMCID: PMC6253418, DOI: 10.1093/ofid/ofy210.1261.Peer-Reviewed Original ResearchInvasive pneumococcal diseaseStreptococcus pneumoniaeIPD casesPneumococcal diseaseVaccine serotypesIncidence of IPDCommon clinical presentationIntroduction of PCV13Pneumococcal conjugate vaccineOverall mortality rateChildhood immunization scheduleSickle cell diseaseYears of ageEnhanced surveillance systemIPD incidenceCommon comorbiditiesConjugate vaccineMassachusetts childrenClinical presentationImmunization scheduleCurrent epidemiologyCNS diseaseHematologic malignanciesCell diseaseClinical data2555. Predicting Risk of Breakthrough Invasive Pneumococcal Disease in Children After 13-Valent Pneumococcal Conjugate Vaccination
Yildirim M, Pelton S, Keskinocak P, Yildirim I. 2555. Predicting Risk of Breakthrough Invasive Pneumococcal Disease in Children After 13-Valent Pneumococcal Conjugate Vaccination. Open Forum Infectious Diseases 2018, 5: s68-s69. PMCID: PMC6252819, DOI: 10.1093/ofid/ofy209.163.Peer-Reviewed Original ResearchPCV13 vaccinationNonvaccine serotypesIncomplete vaccinationThirteen-valent pneumococcal conjugate vaccineDose of PCV7Pneumococcal conjugate vaccinationInvasive pneumococcal diseaseChildhood immunization scheduleCases of IPDStreptococcus pneumoniae isolatesYears of ageEnhanced surveillance systemConjugate vaccinationPCV13 immunizationVT-IPDPneumococcal pneumoniaIPD casesConjugate vaccineIncomplete immunizationPneumococcal diseasePneumococcal infectionComorbid conditionsImmunization scheduleComplete immunizationClinical dataThe relative invasive disease potential of Streptococcus pneumoniae among children after PCV introduction: A systematic review and meta-analysis
Balsells E, Dagan R, Yildirim I, Gounder PP, Steens A, Muñoz-Almagro C, Mameli C, Kandasamy R, Lavi N, Daprai L, van der Ende A, Trzciński K, Nzenze SA, Meiring S, Foster D, Bulkow LR, Rudolph K, Valero-Rello A, Ducker S, Vestrheim DF, von Gottberg A, Pelton SI, Zuccotti G, Pollard AJ, Sanders EAM, Campbell H, Madhi SA, Nair H, Kyaw MH. The relative invasive disease potential of Streptococcus pneumoniae among children after PCV introduction: A systematic review and meta-analysis. Journal Of Infection 2018, 77: 368-378. PMID: 29964140, DOI: 10.1016/j.jinf.2018.06.004.Peer-Reviewed Original ResearchConceptsInvasive pneumococcal diseaseInvasive disease potentialPneumococcal conjugate vaccineNon-vaccine typesPCV introductionPneumococcal diseaseClinical syndromePneumococcal serotypesSurveillance of IPDDisease potentialSystematic reviewCurrent pneumococcal conjugate vaccinesYears of ageRandom-effects modelConjugate vaccineRoutine immunisationDisease presentationFuture vaccinesStreptococcus pneumoniaeSerotype 1SerotypesSyndromeCarriageChildrenVaccine
2017
Invasive Pneumococcal Disease in Massachusetts Children 6 Years Following Introduction of PCV13
Yildirim I, Little B, Pelton S. Invasive Pneumococcal Disease in Massachusetts Children 6 Years Following Introduction of PCV13. Open Forum Infectious Diseases 2017, 4: s67-s67. DOI: 10.1093/ofid/ofx162.159.Peer-Reviewed Original ResearchInvasive pneumococcal diseaseYears of ageNonvaccine serotypesSpeaker honorariaStreptococcus pneumoniaePneumococcal diseaseVaccine serotypesIncidence of IPDImplementation of PCV13Common clinical presentationIntroduction of PCV13Overall mortality rateChildhood immunization scheduleChildren 6 yearsProportion of casesMA childrenEnhanced surveillance systemIPD incidenceMerck vaccineIPD casesConjugate vaccinePCV13 eraClinical presentationComorbid conditionsImmunization scheduleSurveillance of pneumococcal colonization and invasive pneumococcal disease reveals shift in prevalent carriage serotypes in Massachusetts’ children to relatively low invasiveness
Yildirim I, Little BA, Finkelstein J, Lee G, Hanage WP, Shea K, Pelton SI, T, Health H. Surveillance of pneumococcal colonization and invasive pneumococcal disease reveals shift in prevalent carriage serotypes in Massachusetts’ children to relatively low invasiveness. Vaccine 2017, 35: 4002-4009. PMID: 28645717, DOI: 10.1016/j.vaccine.2017.05.077.Peer-Reviewed Original ResearchConceptsInvasive pneumococcal diseasePneumococcal conjugate vaccineInvasive disease potentialPneumococcal diseaseLow invasive capacityInvasive capacityPCV13 eraCommon serotypesIncidence of IPDNasopharyngeal colonization ratePost-vaccine eraDisease potentialCarriage serotypesPCV eraConjugate vaccineNasopharyngeal carriageCarriage prevalencePneumococcal colonizationEnhanced surveillanceDynamic epidemiologyAge groupsSerotype 3Serotype XOlder childrenLow invasiveness
2015
Pneumococcal Disease in the Era of Pneumococcal Conjugate Vaccine
Yildirim I, Shea KM, Pelton SI. Pneumococcal Disease in the Era of Pneumococcal Conjugate Vaccine. Infectious Disease Clinics Of North America 2015, 29: 679-697. PMID: 26610421, PMCID: PMC4662776, DOI: 10.1016/j.idc.2015.07.009.Peer-Reviewed Original ResearchConceptsPneumococcal conjugate vaccinePneumococcal diseaseConjugate vaccineOtitis mediaUniversal immunizationAcute otitis mediaInvasive pneumococcal diseaseCase fatality rateVulnerable pediatric patientsSpectrum of serotypesCause pneumoniaPediatric patientsComorbid conditionsHealthy childrenFatality rateDiseaseHost susceptibilityImmunizationVaccineHigh rateChildrenEmpyemaMastoiditisPneumoniaPatientsVaccination, Underlying Comorbidities, and Risk of Invasive Pneumococcal Disease
Yildirim I, Shea KM, Little BA, Silverio AL, Pelton SI. Vaccination, Underlying Comorbidities, and Risk of Invasive Pneumococcal Disease. Pediatrics 2015, 135: 495-503. PMID: 25647674, DOI: 10.1542/peds.2014-2426.Peer-Reviewed Original ResearchMeSH KeywordsBacterial CapsulesChildChild, PreschoolComorbidityFemaleFollow-Up StudiesHumansIncidenceInfantMaleMassachusettsPneumococcal InfectionsPneumococcal VaccinesPopulation SurveillancePrognosisRetrospective StudiesRisk AssessmentRisk FactorsStreptococcus pneumoniaeVaccinationVaccines, ConjugateConceptsInvasive pneumococcal diseasePneumococcal diseaseUnderlying conditionOutcomes of IPDPrevention of IPDChildhood invasive pneumococcal diseasePneumococcal vaccination statusPolysaccharide pneumococcal vaccineYear of diagnosisPrimary care providersCase fatality rateChronic respiratory diseasesImmunocompromising conditionsIPD diagnosisUnderlying comorbiditiesImmunization PracticesIPD casesPneumococcal vaccineVaccination statusConjugate vaccineMassachusetts childrenClinical presentationSerotype distributionHigher hospitalizationClinical data
2012
Evolving Picture of Invasive Pneumococcal Disease in Massachusetts Children
Yildirim I, Stevenson A, Hsu KK, Pelton SI. Evolving Picture of Invasive Pneumococcal Disease in Massachusetts Children. The Pediatric Infectious Disease Journal 2012, 31: 1016-1021. PMID: 22673142, DOI: 10.1097/inf.0b013e3182615615.Peer-Reviewed Original ResearchMeSH KeywordsAdolescentAnti-Bacterial AgentsChildChild, PreschoolCluster AnalysisFemaleHeptavalent Pneumococcal Conjugate VaccineHumansIncidenceInfantMaleMassachusettsMeningitis, PneumococcalMicrobial Sensitivity TestsMultilocus Sequence TypingPneumococcal VaccinesProspective StudiesSepsisSerotypingStreptococcus pneumoniaeConceptsInvasive pneumococcal diseasePneumococcal conjugate vaccine serotypesPneumococcal conjugate vaccineIPD incidence ratesMassachusetts childrenPCV7 eraIPD casesPneumococcal diseaseConjugate vaccineVaccine serotypesSerotype 19AIncidence rateCases of IPDChildhood invasive pneumococcal diseaseHeptavalent pneumococcal conjugate vaccinePopulation-based surveillanceOverall IPD incidence ratesCeftriaxone-resistant isolatesYears of ageAntimicrobial susceptibility testingBacteremic pneumoniaPCV7 serotypesMultilocus sequence typingNonvaccine serotypesClinical presentation
2010
Serotype specific invasive capacity and persistent reduction in invasive pneumococcal disease
Yildirim I, Hanage WP, Lipsitch M, Shea KM, Stevenson A, Finkelstein J, Huang SS, Lee GM, Kleinman K, Pelton SI. Serotype specific invasive capacity and persistent reduction in invasive pneumococcal disease. Vaccine 2010, 29: 283-288. PMID: 21029807, PMCID: PMC3139683, DOI: 10.1016/j.vaccine.2010.10.032.Peer-Reviewed Original ResearchConceptsInvasive pneumococcal diseaseInvasive capacityPneumococcal diseaseIncidence of IPDNew pneumococcal conjugate vaccinesPneumococcal conjugate vaccineSterile body sitesStreptococcus pneumoniae serotypesCarriage serotypesNasopharyngeal acquisitionNP carriagePCV eraReplacement serotypesIPD incidenceRespiratory seasonsConjugate vaccineMassachusetts childrenCarriage prevalenceCommon serotypesPneumoniae serotypesOngoing surveillanceEnhanced surveillanceBody sitesPersistent reductionSerotype XPneumococcal serotypes causing pediatric meningitis in Turkey: application of a new technology in the investigation of cases negative by conventional culture
Ceyhan M, Yildirim I, Sheppard C, George R. Pneumococcal serotypes causing pediatric meningitis in Turkey: application of a new technology in the investigation of cases negative by conventional culture. European Journal Of Clinical Microbiology & Infectious Diseases 2010, 29: 289-293. PMID: 20087750, DOI: 10.1007/s10096-009-0853-y.Peer-Reviewed Original ResearchConceptsInvasive pneumococcal diseasePolymerase chain reactionPneumococcal diseasePneumococcal serotypesCSF samplesAntigen detectionSurveillance of serotypesPneumococcal conjugate vaccinePrior antibiotic useSerotypes/groupsCerebrospinal fluid samplesYears of agePediatric meningitisBacterial meningitisVaccine impactConjugate vaccineActive surveillanceAntibiotic useCommon serotypesQuellung reactionStreptococcus pneumoniaeAge groupsInvestigation of casesSerotype 5Ply gene