• Analytic comparison between three high-throughput commercial SARS-CoV-2 antibody assays reveals minor discrepancies in a high-incidence population 

      Nasrallah, Gheyath K; Dargham, Soha R; Shurrab, Farah; Al-Sadeq, Duaa W; Al-Jighefee, Hadeel; ... more authors ( Nature Research , 2021 , Article)
      Performance of three automated commercial serological IgG-based assays was investigated for assessing SARS-CoV-2 "ever" (past or current) infection in a population-based sample in a high exposure setting. PCR and serological ...
    • Association of Prior SARS-CoV-2 Infection With Risk of Breakthrough Infection Following mRNA Vaccination in Qatar. 

      Abu-Raddad, Laith J; Chemaitelly, Hiam; Ayoub, Houssein H; Yassine, Hadi M; Benslimane, Fatiha M; ... more authors ( American Medical Association , 2021 , Article)
      The effect of prior SARS-CoV-2 infection on vaccine protection remains poorly understood. To assess protection from SARS-CoV-2 breakthrough infection after mRNA vaccination among persons with vs without prior SARS-CoV-2 ...
    • BNT162b2 and mRNA-1273 COVID-19 vaccine effectiveness against the SARS-CoV-2 Delta variant in Qatar. 

      Tang, Patrick; Hasan, Mohammad R; Chemaitelly, Hiam; Yassine, Hadi M; Benslimane, Fatiha M; ... more authors ( Nature Researc , 2021 , Article)
      With the global expansion of the highly transmissible SARS-CoV-2 Delta (B.1.617.2) variant, we conducted a matched test-negative case-control study to assess the real-world effectiveness of COVID-19 messenger RNA vaccines ...
    • BNT162b2 antigen dose and SARS-CoV-2 omicron infection in adolescents 

      Chemaitelly, Hiam; Ayoub, Houssein H.; Coyle, Peter; Tang, Patrick; Yassine, Hadi M.; ... more authors ( Elsevier , 2023 , Other)
      COVID-19 vaccine antigen dose might affect protection against SARS-CoV-2 infection,1, 2 but direct evidence to quantify this effect is absent. We conducted a matched, retrospective, cohort study using a regression ...
    • Characterizing the effective reproduction number during the COVID-19 pandemic: Insights from Qatar’s experience 

      Bsat, Raghid; Chemaitelly, Hiam; Coyle, Peter; Tang, Patrick; Hasan, Mohammad R; ... more authors ( International Society of Global Health , 2022 , Article)
      Background: The effective reproduction number, Rt, is a tool to track and understand epidemic dynamics. This investigation of Rt estimations was conducted to guide the national COVID-19 response in Qatar, from the onset ...
    • COVID-19 risk score as a public health tool to guide targeted testing: A demonstration study in Qatar 

      J. Abu-Raddad, Laith; Dargham, Soha; Chemaitelly, Hiam; Coyle, Peter; Al Kanaani, Zaina; ... more authors ( Public Library of Science , 2022 , Article)
      We developed a Coronavirus Disease 2019 (COVID-19) risk score to guide targeted RTPCR testing in Qatar. The Qatar national COVID-19 testing database, encompassing a total of 2,688,232 RT-PCR tests conducted between February ...
    • Duration of immune protection of SARS-CoV-2 natural infection against reinfection. 

      Chemaitelly, Hiam; Nagelkerke, Nico; Ayoub, Houssein H; Coyle, Peter; Tang, Patrick; ... more authors ( Oxford University Press , 2022 , Article)
      The future of the SARS-CoV-2 pandemic hinges on virus evolution and duration of immune protection of natural infection against reinfection. We investigated duration of protection afforded by natural infection, the effect ...
    • Duration of mRNA vaccine protection against SARS-CoV-2 Omicron BA.1 and BA.2 subvariants in Qatar. 

      Chemaitelly, Hiam; Ayoub, Houssein H; AlMukdad, Sawsan; Coyle, Peter; Tang, Patrick; ... more authors ( Nature Research , 2022 , Article)
      SARS-CoV-2 Omicron BA.1 and BA.2 subvariants are genetically divergent. We conducted a matched, test-negative, case-control study to estimate duration of protection of the second and third/booster doses of mRNA COVID-19 ...
    • Effect of mRNA Vaccine Boosters against SARS-CoV-2 Omicron Infection in Qatar. 

      Abu-Raddad, Laith J; Chemaitelly, Hiam; Ayoub, Houssein H; AlMukdad, Sawsan; Yassine, Hadi M; ... more authors ( Massachusetts Medical Society , 2022 , Article)
      Waning of vaccine protection against coronavirus disease 2019 (Covid-19) and the emergence of the omicron (or B.1.1.529) variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have led to expedited ...
    • Effects of BA.1/BA.2 subvariant, vaccination, and prior infection on infectiousness of SARS-CoV-2 omicron infections. 

      Qassim, Suelen H; Chemaitelly, Hiam; Ayoub, Houssein H; AlMukdad, Sawsan; Tang, Patrick; ... more authors ( Oxford University Press , 2022 , Article)
      Compared to BA.1, BA.2 was associated with lower RT-qPCR cycle threshold (Ct) value-3.53 fewer cycles (95% CI: 3.46-3.60), signifying higher infectiousness. This may reflect higher viral load and/or longer duration of ...
    • Effects of Previous Infection and Vaccination on Symptomatic Omicron Infections. 

      Altarawneh, Heba N; Chemaitelly, Hiam; Ayoub, Houssein H; Tang, Patrick; Hasan, Mohammad R; ... more authors ( Massachusetts Medical Society , 2022 , Article)
      The protection conferred by natural immunity, vaccination, and both against symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with the BA.1 or BA.2 sublineages of the omicron (B.1.1.529) ...
    • Effects of previous infection, vaccination, and hybrid immunity against symptomatic Alpha, Beta, and Delta SARS-CoV-2 infections: an observational study 

      Heba N., Altarawneh; Chemaitelly, Hiam; Ayoub, Houssein H.; Tang, Patrick; Hasan, Mohammad R.; ... more authors ( Elsevier , 2023 , Article)
      BackgroundProtection against SARS-CoV-2 symptomatic infection and severe COVID-19 of previous infection, mRNA two-dose vaccination, mRNA three-dose vaccination, and hybrid immunity of previous infection and vaccination ...
    • Effects of SARS-CoV-2 Alpha, Beta, and Delta variants, age, vaccination, and prior infection on infectiousness of SARS-CoV-2 infections 

      Qassim, Suelen H.; Hasan, Mohammad R.; Tang, Patrick; Chemaitelly, Hiam; Ayoub, Houssein H.; ... more authors ( Frontiers Media , 2022 , Article)
      In 2021, Qatar experienced considerable incidence of SARS-CoV-2 infection that was dominated sequentially by the Alpha, Beta, and Delta variants. Using the cycle threshold (Ct) value of an RT-qPCR-positive test to proxy ...
    • Epidemiological impact of prioritising SARS-CoV-2 vaccination by antibody status: Mathematical modelling analyses 

      Ayoub, H.H.; Ayoub, Houssein H.; Chemaitelly, Hiam; Makhoul, Monia; Al Kanaani, Zaina; ... more authors ( BMJ Publishing Group , 2021 , Article)
      Background Vaccines against SARS-CoV-2 have been developed, but their availability falls far short of global needs. This study aimed to investigate the impact of prioritising available doses on the basis of recipient ...
    • Estimating protection afforded by prior infection in preventing reinfection: Applying the test-negative study design. 

      Ayoub, Houssein H; Tomy, Milan; Chemaitelly, Hiam; Altarawneh, Heba N; Coyle, Peter; ... more authors ( Oxford University Press , 2023 , Article)
      The COVID-19 pandemic has highlighted the need to use infection testing databases to rapidly estimate effectiveness of prior infection in preventing reinfection ($P{E}_S$) by novel SARS-CoV-2 variants. Mathematical modeling ...
    • History of primary-series and booster vaccination and protection against Omicron reinfection 

      Chemaitelly, Hiam; Ayoub, Houssein H.; Tang, Patrick; Coyle, Peter V.; Yassine, Hadi M.; ... more authors ( American Association for the Advancement of Science , 2023 , Article)
      Laboratory evidence suggests a possibility of immune imprinting for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We investigated the differences in the incidence of SARS-CoV-2 reinfection in a ...
    • Introduction and expansion of the SARS-CoV-2 B.1.1.7 variant and reinfections in Qatar: A nationally representative cohort study 

      J. Abu-Raddad, Laith; Chemaitelly, Hiam; H. Ayoub, Houssein; Coyle, Peter; A. Malek, Joel; ... more authors ( Public Library of Science , 2021 , Article)
      Background The epidemiology of the SARS-CoV-2 B.1.1.7 (or Alpha) variant is insufficiently understood. This study’s objective was to describe the introduction and expansion of this variant in Qatar and to estimate the ...
    • Long-term COVID-19 booster effectiveness by infection history and clinical vulnerability and immune imprinting: a retrospective population-based cohort study 

      Hiam, Chemaitelly; Ayoub, Houssein H; Tang, Patrick; Coyle, Peter; Yassine, Hadi M; ... more authors ( Elsevier , 2023 , Article)
      BackgroundLong-term effectiveness of COVID-19 mRNA boosters in populations with different previous infection histories and clinical vulnerability profiles is inadequately understood. We aimed to investigate the effectiveness ...
    • mRNA-1273 COVID-19 vaccine effectiveness against the B.1.1.7 and B.1.351 variants and severe COVID-19 disease in Qatar 

      Chemaitelly, Hiam; Yassine, Hadi M.; Benslimane, Fatiha M.; Al Khatib, Hebah A.; Tang, Patrick; ... more authors (2021 , Article)
      The SARS-CoV-2 pandemic continues to be a global health concern. The mRNA-1273 (Moderna) vaccine was reported to have an efficacy of 94.1% at preventing symptomatic COVID-19 due to infection with ‘wild-type’ variants in a ...
    • A new One Health Framework in Qatar for future emerging and re-emerging zoonotic diseases preparedness and response 

      Devendra, Bansal; Jaffrey, Shariq; Al-Emadi, Noora Abdulla; Hassan, Mahmoud; Islam, Md. Mazharul; ... more authors ( Elsevier , 2023 , Article)
      One Health is increasingly recognized as an optimal approach to address the global risk of health threats originating at the human, animal, and ecosystem interface, and their impact. Qatar has successfully practiced One ...