• 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 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 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 ...
    • 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 ...
    • One Year of SARS-CoV-2: Genomic Characterization of COVID-19 Outbreak in Qatar 

      Benslimane, Fatiha M; Al Khatib, Hebah A; Al-Jamal, Ola; Albatesh, Dana; Boughattas, Sonia; ... more authors ( Frontiers , 2021 , Article)
      Qatar, a country with a strong health system and a diverse population consisting mainly of expatriate residents, has experienced two large waves of COVID-19 outbreak. In this study, we report on 2634 SARS-CoV-2 whole-genome ...
    • Population immunity of natural infection, primary-series vaccination, and booster vaccination in Qatar during the COVID-19 pandemic: an observational study 

      Suelen H., Qassim; Chemaitelly, Hiam; Ayoub, Houssein H.; Coyle, Peter; Tang, Patrick; ... more authors ( Elsevier , 2023 , Article)
      BackgroundWaning of natural infection protection and vaccine protection highlight the need to evaluate changes in population immunity over time. Population immunity of previous SARS-CoV-2 infection or of COVID-19 vaccination ...
    • Protection against Reinfection with the Omicron BA.2.75 Subvariant 

      Chemaitelly, Hiam; Tang, Patrick; Coyle, Peter; Yassine, Hadi M.; Al-Khatib, Hebah A.; ... more authors ( Massachusetts Medical Society , 2023 , Other)
      The BA.2.75 sublineage of the B.1.1.529 (omicron) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may escape neutralizing antibodies. The BA.2.75 sublineage (primarily the BA.2.75.2 subvariant) ...
    • Protection from previous natural infection compared with mRNA vaccination against SARS-CoV-2 infection and severe COVID-19 in Qatar: a retrospective cohort study 

      Hiam, Chemaitelly; Ayoub, Houssein H; AlMukdad, Sawsan; Coyle, Peter; Tang, Patrick; ... more authors ( Elsevier , 2022 , Article)
      BackgroundUnderstanding protection conferred by natural SARS-CoV-2 infection versus COVID-19 vaccination is important for informing vaccine mandate decisions. We compared protection conferred by natural infection versus ...
    • Protective Effect of Previous SARS-CoV-2 Infection against Omicron BA.4 and BA.5 Subvariants. 

      Altarawneh, Heba N; Chemaitelly, Hiam; Ayoub, Houssein H; Hasan, Mohammad R; Coyle, Peter; ... more authors ( Massachusetts Medical Society , 2022 , Article)
      The BA.4 and BA.5 subvariants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.1.529 (omicron) variant have shown the capacity of escaping from neutralizing antibodies.1 These subvariants had an ...
    • Short- and longer-term all-cause mortality among SARS-CoV-2- infected individuals and the pull-forward phenomenon in Qatar: a national cohort study 

      Hiam, Chemaitelly; Faust, Jeremy Samuel; Krumholz, Harlan M.; Ayoub, Houssein H.; Tang, Patrick; ... more authors ( Elsevier , 2023 , Article)
      ObjectivesWe assessed short-, medium-, and long-term all-cause mortality risks after a primary SARS-CoV-2 infection. MethodsA national, matched, retrospective cohort study was conducted in Qatar to assess risk of all-cause ...