2022
Use of Recently Vaccinated Individuals to Detect Bias in Test-Negative Case–Control Studies of COVID-19 Vaccine Effectiveness
Hitchings MDT, Lewnard JA, Dean NE, Ko AI, Ranzani OT, Andrews JR, Cummings DAT. Use of Recently Vaccinated Individuals to Detect Bias in Test-Negative Case–Control Studies of COVID-19 Vaccine Effectiveness. Epidemiology 2022, 33: 450-456. PMID: 35384900, PMCID: PMC9148635, DOI: 10.1097/ede.0000000000001484.Peer-Reviewed Original ResearchConceptsCOVID-19 vaccine effectivenessVaccine effectivenessNegative control exposureObservational studyControl exposurePhase III trialsTest-negative studiesTest-negative casesVaccine effectiveness estimatesCOVID-19 vaccineDemonstration of efficacyCOVID-19 riskIII trialsUnvaccinated individualsClinical trialsControl studyStudy designEffectiveness estimatesCareful study designUnmeasured confoundingSelection biasTrialsConfoundingExposureIndividuals
2021
Effectiveness of CoronaVac among healthcare workers in the setting of high SARS-CoV-2 Gamma variant transmission in Manaus, Brazil: A test-negative case-control study
Hitchings MDT, Ranzani OT, Torres MSS, de Oliveira SB, Almiron M, Said R, Borg R, Schulz WL, de Oliveira RD, da Silva PV, de Castro DB, de Souza Sampaio V, de Albuquerque BC, Ramos TCA, Fraxe SHH, da Costa CF, Naveca FG, Siqueira AM, de Araújo WN, Andrews JR, Cummings DAT, Ko AI, Croda J. Effectiveness of CoronaVac among healthcare workers in the setting of high SARS-CoV-2 Gamma variant transmission in Manaus, Brazil: A test-negative case-control study. The Lancet Regional Health - Americas 2021, 1: 100025. PMID: 34386791, PMCID: PMC8310555, DOI: 10.1016/j.lana.2021.100025.Peer-Reviewed Original ResearchSymptomatic SARS-CoV-2 infectionSARS-CoV-2 infectionTwo-dose scheduleTest-negative case-control studyEffectiveness of CoronaVacCase-control studyHealthcare workersVariant transmissionVaccine doseFirst doseSecond doseSample collection dateSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variantsDose of CoronaVacTest-negative studiesVaccine effectiveness estimatesEffectiveness of vaccinesRT-PCR testingCase-control pairsRT-PCR testMunicipal Health SecretarySARS-CoV-2 samplesNon-pharmaceutical interventionsPeriod 14 daysUnvaccinated individuals