2024
5-year vaccine protection following a single dose of Vi-tetanus toxoid conjugate vaccine in Bangladeshi children (TyVOID): a cluster randomised trial
Qadri F, Khanam F, Zhang Y, Biswas P, Voysey M, Mujadidi Y, Kelly S, Bhuiyan A, Rajib N, Hossen I, Rahman N, Islam S, Pitzer V, Kim Y, Clemens J, Pollard A, Liu X. 5-year vaccine protection following a single dose of Vi-tetanus toxoid conjugate vaccine in Bangladeshi children (TyVOID): a cluster randomised trial. The Lancet 2024, 404: 1419-1429. PMID: 39396349, DOI: 10.1016/s0140-6736(24)01494-6.Peer-Reviewed Original ResearchConceptsTyphoid conjugate vaccineJapanese encephalitis vaccineVaccine effectivenessRandomised controlled trialsConjugate vaccineFollow-upTyphoid feverControlled trialsVaccine protectionChildren aged 9 monthsIncreased risk of typhoid feverAnti-Vi IgGRisk of typhoid feverVaccine efficacy dataTest-negative designAged 9 monthsUnvaccinated individualsHigh-burden countriesIncidence rate ratiosAnalyses of vaccine effectivenessSingle-doseSingle doseDecay of antibodiesSubgroup analysisBooster dose
2023
Typhoid fever
Meiring J, Khanam F, Basnyat B, Charles R, Crump J, Debellut F, Holt K, Kariuki S, Mugisha E, Neuzil K, Parry C, Pitzer V, Pollard A, Qadri F, Gordon M. Typhoid fever. Nature Reviews Disease Primers 2023, 9: 71. PMID: 38097589, DOI: 10.1038/s41572-023-00480-z.Peer-Reviewed Original ResearchConceptsTyphoid feverUndifferentiated febrile illnessInvasive bacterial diseaseEffective vaccination programsFecal-oral routeNovel diagnostic modalitiesFebrile illnessBloodstream infectionsVaccination programBlood culturesClinical trialsImmunological protectionHigh burdenCausative organismDiagnostic modalitiesGlobal burdenDisease pathogenesisFeverHuman infectionsIntestinal epitheliumYoung adultsCulture testingSalmonella enterica subspSerovar TyphiAntimicrobial resistanceAssessing the global risk of typhoid outbreaks caused by extensively drug resistant Salmonella Typhi
Walker J, Chaguza C, Grubaugh N, Carey M, Baker S, Khan K, Bogoch I, Pitzer V. Assessing the global risk of typhoid outbreaks caused by extensively drug resistant Salmonella Typhi. Nature Communications 2023, 14: 6502. PMID: 37845201, PMCID: PMC10579367, DOI: 10.1038/s41467-023-42353-9.Peer-Reviewed Original ResearchConceptsXDR S. TyphiS. typhiDrug-resistant Salmonella enterica serovar TyphiDrug-resistant Salmonella TyphiTyphoid outbreakMajor public health threatResistant Salmonella typhiPublic health activitiesTyphoid fever incidencePublic health threatSalmonella enterica serovar TyphiXDR typhoidEnterica serovar TyphiH58 haplotypeHigh riskOnward transmissionTyphoid feverSignificant associationHealth activitiesFever incidenceHealth threatFuture outbreaksSerovar TyphiSalmonella typhiTyphiCost-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 definitions
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 ResearchMeSH KeywordsCost-Benefit AnalysisHumansPublic HealthTyphoid FeverTyphoid-Paratyphoid VaccinesVaccines, ConjugateConceptsIncremental 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 transmissionMonths
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 ResearchMeSH KeywordsClinical Trials as TopicCongresses as TopicHumansTyphoid FeverTyphoid-Paratyphoid VaccinesVaccines, ConjugateConceptsTyphoid 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
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