2024
Impact of dosing schedules on performance of rotavirus vaccines in Ghana
Asare E, Al-Mamun M, Armah G, Lopman B, Pitzer V. Impact of dosing schedules on performance of rotavirus vaccines in Ghana. Science Advances 2024, 10: eadn4176. PMID: 39661683, PMCID: PMC11633732, DOI: 10.1126/sciadv.adn4176.Peer-Reviewed Original ResearchConceptsVaccine dosing schedulesDosing scheduleDoses of RV1Median percentage reductionImprove vaccine performanceRotavirus vaccine impactThird doseRotavirus vaccineRotarix vaccineVaccine impactAdditional doseVaccine effectivenessVaccine performanceVaccineRotavirusRV1Percentage reductionChildrenRotarixImpact of rotavirus vaccination in Malawi from 2012 to 2022 compared to model predictions
Pitzer V, Ndeketa L, Asare E, Hungerford D, Lopman B, Jere K, Cunliffe N. Impact of rotavirus vaccination in Malawi from 2012 to 2022 compared to model predictions. Npj Vaccines 2024, 9: 227. PMID: 39562592, PMCID: PMC11576906, DOI: 10.1038/s41541-024-01008-6.Peer-Reviewed Original ResearchRotavirus-associated gastroenteritisRotavirus-negative childrenRotavirus-negative controlsImpact of rotavirus vaccinationVaccination coverageRotavirus vaccine impactAcute gastroenteritis casesNational immunization programPre-vaccination dataVaccine introductionRotavirus vaccineVaccine impactAcute gastroenteritisVaccine effectivenessGastroenteritis casesLow-income settingsImmunization programsVaccine
2023
Assessment of vaccine herd protection in a cluster-randomised trial of Vi conjugate vaccine against typhoid fever: results of further analysis
Khanam F, Kim D, Liu X, Voysey M, Pitzer V, Zaman K, Pollard A, Qadri F, Clemens J. Assessment of vaccine herd protection in a cluster-randomised trial of Vi conjugate vaccine against typhoid fever: results of further analysis. EClinicalMedicine 2023, 58: 101925. PMID: 37090439, PMCID: PMC10114505, DOI: 10.1016/j.eclinm.2023.101925.Peer-Reviewed Original ResearchVaccine herd protectionCluster-randomised trialHerd protectionTransmission of typhoidVi-TTTyphoid feverChildren 9 monthsVi-tetanus toxoidMonths of followJapanese encephalitis vaccineYears of ageTotal vaccine effectivenessUrban Bangladeshi childrenVaccine effectivenessEncephalitis vaccineStudy populationBangladeshi childrenTreatment centersCluster residentsIndirect effectivenessMelinda Gates FoundationTrialsVaccineAnalysis of subpopulationsFever
2017
The Typhoid Vaccine Acceleration Consortium (TyVAC): Vaccine effectiveness study designs: Accelerating the introduction of typhoid conjugate vaccines and reducing the global burden of enteric fever. Report from a meeting held on 26–27 October 2016, Oxford, UK
Meiring J, Gibani M, Group: T, Basnyat, Bentsi-Enchill A, Clemens J, Darton T, Date K, Dougan G, Garrett D, Gessner B, Gordon M, Heyderman R, Hombach J, Kotloff K, Levine M, Luby S, Mohan V, Marfin A, Mulholland K, Neuzil K, Pitzer V, Pollard A, Qadri F, Salisbury D, Zaidi A. The Typhoid Vaccine Acceleration Consortium (TyVAC): Vaccine effectiveness study designs: Accelerating the introduction of typhoid conjugate vaccines and reducing the global burden of enteric fever. Report from a meeting held on 26–27 October 2016, Oxford, UK. Vaccine 2017, 35: 5081-5088. PMID: 28802757, DOI: 10.1016/j.vaccine.2017.08.001.Peer-Reviewed Original ResearchConceptsTyphoid Vaccine Acceleration ConsortiumEffectiveness study designStudy designImportant public health toolIntroduction of TCVsHigh disease burdenStrategic Advisory GroupPublic health toolGAVI-eligible countriesCost-effectiveness analysisIntroduction of typhoidEnteric feverPrevious vaccinesTyphoid vaccineDisease burdenEfficacious vaccineGlobal burdenCountry-level decisionsTyphoid epidemiologyTyphoid feverLatest evidenceVaccineTyphoid surveillanceEffectiveness studiesHealth tools
2016
Strategies to Prevent Cholera Introduction during International Personnel Deployments: A Computational Modeling Analysis Based on the 2010 Haiti Outbreak
Lewnard JA, Antillón M, Gonsalves G, Miller AM, Ko AI, Pitzer VE. Strategies to Prevent Cholera Introduction during International Personnel Deployments: A Computational Modeling Analysis Based on the 2010 Haiti Outbreak. PLOS Medicine 2016, 13: e1001947. PMID: 26812236, PMCID: PMC4727895, DOI: 10.1371/journal.pmed.1001947.Peer-Reviewed Original ResearchConceptsOral cholera vaccineProbability of casesAntimicrobial chemoprophylaxisCholera vaccineOral cholera vaccinationAntimicrobial regimensProphylactic efficacyAsymptomatic carriageCholera vaccinationAsymptomatic carriersIncidence rateLargest cholera epidemicCholera epidemicChemoprophylaxisCholera incidence ratesFalse-positive test outcomesVaccinationFirst weekDiagnostic screeningAntimicrobial chemotherapyHaiti cholera epidemicIntervention strategiesVaccineIndependent panelCholera importation
2015
Did Large-Scale Vaccination Drive Changes in the Circulating Rotavirus Population in Belgium?
Pitzer VE, Bilcke J, Heylen E, Crawford FW, Callens M, De Smet F, Van Ranst M, Zeller M, Matthijnssens J. Did Large-Scale Vaccination Drive Changes in the Circulating Rotavirus Population in Belgium? Scientific Reports 2015, 5: 18585. PMID: 26687288, PMCID: PMC4685644, DOI: 10.1038/srep18585.Peer-Reviewed Original ResearchConceptsVaccine introductionStrain-specific vaccine effectivenessVaccine-derived immunityRotavirus vaccine introductionVaccine-induced immunityAbsence of vaccinationRotavirus populationLarge-scale vaccinationDistribution of genotypesRotavirus gastroenteritisVaccine effectivenessHomotypic strainHospitalization dataPredominant rotavirusStrain replacementVaccinationVaccineImmunityInfectionViral populationsPopulationGastroenteritisYearsIncidenceRotavirus
2012
Understanding Reduced Rotavirus Vaccine Efficacy in Low Socio-Economic Settings
Lopman BA, Pitzer VE, Sarkar R, Gladstone B, Patel M, Glasser J, Gambhir M, Atchison C, Grenfell BT, Edmunds WJ, Kang G, Parashar UD. Understanding Reduced Rotavirus Vaccine Efficacy in Low Socio-Economic Settings. PLOS ONE 2012, 7: e41720. PMID: 22879893, PMCID: PMC3412858, DOI: 10.1371/journal.pone.0041720.Peer-Reviewed Original ResearchConceptsLow socio-economic settingRotavirus vaccine efficacyVaccine efficacyRotavirus vaccineSevere diseaseNatural infectionImmunogenicity of vaccinationReduced vaccine efficacySevere rotavirus gastroenteritisReduced efficacyClinical trial resultsLow SES populationsRotavirus gastroenteritisVaccine performanceVaccination programImmune responseEpidemiological factorsVaccineVaccinationTrial resultsInfectionSES populationsEfficacyReduced protectionEfficacy declines
2011
Modeling rotavirus strain dynamics in developed countries to understand the potential impact of vaccination on genotype distributions
Pitzer VE, Patel MM, Lopman BA, Viboud C, Parashar UD, Grenfell BT. Modeling rotavirus strain dynamics in developed countries to understand the potential impact of vaccination on genotype distributions. Proceedings Of The National Academy Of Sciences Of The United States Of America 2011, 108: 19353-19358. PMID: 22084114, PMCID: PMC3228484, DOI: 10.1073/pnas.1110507108.Peer-Reviewed Original ResearchConceptsHeterotypic immunityCommon rotavirus genotypesPredominance of G1Impact of vaccinationVaccine-type strainsDistribution of genotypesPrevaccination levelsRotavirus incidenceRotavirus genotypesVaccinationGenotype distributionImmunityGenotype patternsRelative prevalenceVaccineIncidenceStrong immunityFrequency of cyclingDisease incidenceGenotypesStrong protectionNew strainG1HomotypicPrevalence