2023
Changes in Population Immunity Against Infection and Severe Disease From Severe Acute Respiratory Syndrome Coronavirus 2 Omicron Variants in the United States Between December 2021 and November 2022
Klaassen F, Chitwood M, Cohen T, Pitzer V, Russi M, Swartwood N, Salomon J, Menzies N. Changes in Population Immunity Against Infection and Severe Disease From Severe Acute Respiratory Syndrome Coronavirus 2 Omicron Variants in the United States Between December 2021 and November 2022. Clinical Infectious Diseases 2023, 77: 355-361. PMID: 37074868, PMCID: PMC10425195, DOI: 10.1093/cid/ciad210.Peer-Reviewed Original ResearchConceptsSevere diseasePopulation immunityOmicron infectionOmicron variantUS populationSevere acute respiratory syndrome coronavirus 2Acute respiratory syndrome coronavirus 2SARS-CoV-2 infectionRespiratory syndrome coronavirus 2SARS-CoV-2 Omicron variantRestoration of immunitySyndrome coronavirus 2Bayesian evidence synthesis modelInfection-acquired immunityEvidence synthesis modelSARS-CoV-2Prior immunological exposureCoronavirus 2Additional infectionsImmunological exposureInfectionDiseaseImmunityVaccinationUnited StatesCost-effectiveness analysis of typhoid conjugate vaccines in an outbreak setting: a modeling study
Phillips M, Antillon M, Bilcke J, Bar-Zeev N, Limani F, Debellut F, Pecenka C, Neuzil K, Gordon M, Thindwa D, Paltiel A, Yaesoubi R, Pitzer V. Cost-effectiveness analysis of typhoid conjugate vaccines in an outbreak setting: a modeling study. BMC Infectious Diseases 2023, 23: 143. PMID: 36890448, PMCID: PMC9993384, DOI: 10.1186/s12879-023-08105-2.Peer-Reviewed Original ResearchConceptsTyphoid Conjugate VaccineRoutine vaccinationReactive vaccinationVaccination strategiesOutbreak settingsMultidrug-resistant Salmonella typhiQueen Elizabeth Central HospitalTyphoid fever epidemicYears of ageMonths of ageCost-effectiveness analysisWorld Health OrganizationConjugate vaccineCentral HospitalRoutine immunizationVaccine deploymentPreventive vaccinationVaccinationTyphoid feverCost-effective strategyAge 15Health OrganizationFever epidemicAntimicrobial resistanceOutbreak definitionsPredicting indirect effects of rotavirus vaccination programs on rotavirus mortality among children in 112 countries
Kraay A, Chaney D, Deshpande A, Pitzer V, Lopman B. Predicting indirect effects of rotavirus vaccination programs on rotavirus mortality among children in 112 countries. Npj Vaccines 2023, 8: 32. PMID: 36871093, PMCID: PMC9985632, DOI: 10.1038/s41541-023-00632-y.Peer-Reviewed Original ResearchRotavirus vaccinationVaccine coveragePost-vaccine introductionHigh vaccine coverageRotavirus vaccination programLow vaccine coverageBirth rateWHO European RegionRotavirus deathsRotavirus mortalityRotavirus vaccineMiddle-income countriesVaccine impactDiarrhea deathsVaccination programIndirect protectionVaccinationEffect estimatesMortalityWestern Pacific RegionRegression analysisDirect protectionIncome countriesDeathHigh birth ratePlanning for Mpox on a College Campus: A Model-Based Decision-Support Tool.
Savinkina A, Chitwood M, Kwon J, Pitzer V, Gonsalves G, Paltiel A. Planning for Mpox on a College Campus: A Model-Based Decision-Support Tool. Annals Of Internal Medicine 2023, 176: 340-347. PMID: 36716454, PMCID: PMC10338074, DOI: 10.7326/m22-2734.Peer-Reviewed Original ResearchConceptsSustained transmissionNational InstituteLow-risk groupHigh-risk populationPopulation of MSMHealth-National InstituteResidential college campusSymptomatic casesHypothetical cohortCongregate settingsStudy populationPreemptive vaccinationReactive vaccinationInfectious diseasesVaccinationDrug abuseBasic reproductive numberFuture outbreaksFrequent physical contactMSMReproductive numberOutbreakDaysMenTimely detection
2022
Comparison of model predictions of typhoid conjugate vaccine public health impact and cost-effectiveness
Burrows H, Antillón M, Gauld J, Kim J, Mogasale V, Ryckman T, Andrews J, Lo N, Pitzer V. Comparison of model predictions of typhoid conjugate vaccine public health impact and cost-effectiveness. Vaccine 2022, 41: 965-975. PMID: 36586741, PMCID: PMC9880559, DOI: 10.1016/j.vaccine.2022.12.032.Peer-Reviewed Original ResearchConceptsIncremental cost-effectiveness ratioRoutine vaccinationVaccine impactPublic health impactOne-time catchPotential public health impactHigh-incidence settingsTyphoid fever casesCost-effectiveness ratioMonths of ageHealth impactsModel-predicted outcomesPrimary outcomeChronic carriersIncidence settingsSymptomatic casesVaccine introductionEndemic settingsVaccine deploymentFever casesVaccinationTyphoid casesIncremental costTyphoid transmissionMonthsPredicting the long-term impact of rotavirus vaccination in 112 countries from 2006 to 2034: A transmission modeling analysis
Kraay A, Steele M, Baker J, Hall E, Deshpande A, Saidzosa B, Mukaratirwa A, Boula A, Mpabalwani E, Kiulia N, Tsolenyanu E, Enweronu-Laryea C, Abebe A, Beyene B, Tefera M, Willilo R, Batmunkh N, Pastore R, Mwenda J, Antoni S, Cohen A, Pitzer V, Lopman B. Predicting the long-term impact of rotavirus vaccination in 112 countries from 2006 to 2034: A transmission modeling analysis. Vaccine 2022, 40: 6631-6639. PMID: 36210251, PMCID: PMC10351612, DOI: 10.1016/j.vaccine.2022.09.072.Peer-Reviewed Original ResearchConceptsRotavirus vaccinationRotavirus positivityVaccine introductionOne-dose scheduleTwo-dose seriesRotavirus burdenRotavirus casesRotavirus gastroenteritisHospital admissionMiddle-income countriesVaccine impactVaccinated individualsLong-term impactMortality burdenPercent reductionVaccinationLife yearsIndirect protectionLow-income countriesLong-term magnitudePositivityDeathBurdenYearsIntroduction Data
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 importationIn-season and out-of-season variation of rotavirus genotype distribution and age of infection across 12 European countries before the introduction of routine vaccination, 2007/08 to 2012/13.
Hungerford D, Vivancos R, Read J, Pitzer V, Cunliffe N, French N, Iturriza-Gómara M. In-season and out-of-season variation of rotavirus genotype distribution and age of infection across 12 European countries before the introduction of routine vaccination, 2007/08 to 2012/13. Eurosurveillance 2016, 21 PMID: 26794258, DOI: 10.2807/1560-7917.es.2016.21.2.30106.Peer-Reviewed Original ResearchConceptsGenotype distributionMultinomial multivariate logistic regressionRotavirus gastroenteritis casesRotavirus genotype distributionRoutine rotavirus vaccinationRotavirus vaccination programRotavirus-positive specimensMultivariate logistic regressionOdds of infectionAge of infectionRVGE casesUntypable genotypesRotavirus vaccinationRoutine vaccinationVaccine introductionVaccination programGastroenteritis casesEpidemiological changesGenotype surveillanceLogistic regressionCommon genotypeMicrobiological dataVaccinationSurveillance networkAge
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
2014
Predicting the Impact of Vaccination on the Transmission Dynamics of Typhoid in South Asia: A Mathematical Modeling Study
Pitzer VE, Bowles CC, Baker S, Kang G, Balaji V, Farrar JJ, Grenfell BT. Predicting the Impact of Vaccination on the Transmission Dynamics of Typhoid in South Asia: A Mathematical Modeling Study. PLOS Neglected Tropical Diseases 2014, 8: e2642. PMID: 24416466, PMCID: PMC3886927, DOI: 10.1371/journal.pntd.0002642.Peer-Reviewed Original ResearchConceptsChristian Medical College HospitalSubstantial indirect protectionMedical College HospitalCulture-confirmed casesImpact of vaccinationIncidence of typhoidTransmission dynamicsOne-time campaignChronic carriersCollege HospitalVaccination strategiesEndemic settingsTyphoid feverVaccinationTyphoid infectionTyphoid casesNatural historyIndirect protectionVi polysaccharideBasic reproductive numberTyphoidIncidenceTyphoid incidenceAge distributionReproductive number
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