Browsing by Author "Chemaitelly, Hiam"

Now showing items 1-20 of 50

    • Addressing bias in the definition of SARS-CoV-2 reinfection: implications for underestimation 

      Chemaitelly, Hiam; Ayoub, Houssein H.; Tang, Patrick; Yassine, Hadi M.; Al Thani, Asmaa A.; ... more authors ( Frontiers Media , 2024 , Article)
      Introduction: Reinfections are increasingly becoming a feature in the epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, accurately defining reinfection poses methodological ...

    • All-cause and COVID-19 mortality in Qatar during the COVID-19 pandemic 

      Alnuaimi, Asma A.; Chemaitelly, Hiam; Semaan, Sandy; Almukdad, Sawsan; Al-Kanaani, Zaina; ... more authors ( BMJ Publishing Group , 2023 , Article)
      Objective To investigate all-cause mortality, COVID-19 mortality and all-cause non-COVID-19 mortality in Qatar during the COVID-19 pandemic. Methods A national, retrospective cohort analysis and national, matched, retrospective ...

    • Analyzing inherent biases in SARS-CoV-2 PCR and serological epidemiologic metrics 

      Makhoul, Monia; Abou-Hijleh, Farah; Seedat, Shaheen; Mumtaz, Ghina R.; Chemaitelly, Hiam; ... more authors ( springer nature , 2022 , Article)
      Background: Prospective observational data show that infected persons with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remain polymerase chain reaction (PCR) positive for a prolonged duration, and that ...

    • Assessment of the Risk of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Reinfection in an Intense Reexposure Setting 

      Abu-Raddad, Laith J.; Chemaitelly, Hiam; Malek, Joel A.; Ahmed, Ayeda A.; Mohamoud, Yasmin A.; ... more authors ( NLM (Medline) , 2021 , Article)
      BACKGROUND: Risk of reinfection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unknown. We assessed the risk and incidence rate of documented SARS-CoV-2 reinfection in a cohort of laboratory-confirmed ...

    • Associations of Vaccination and of Prior Infection with Positive PCR Test Results for SARS-CoV-2 in Airline Passengers Arriving in Qatar 

      Bertollini, Roberto; Chemaitelly, Hiam; Yassine, Hadi M.; Al-Thani, Mohamed H.; Al-Khal, Abdullatif; ... more authors ( American Medical Association , 2021 , Article)
      The SARS-CoV-2 pandemic has severely affected international travel. With efficacious COVID-19 vaccines available, Qatar implemented a pilot program between February 18 and April 26, 2021, to ease travel restrictions by ...

    • Bivalent mRNA-1273.214 vaccine effectiveness against SARS-CoV-2 omicron XBB* infections 

      Chemaitelly, Hiam; Ayoub, Houssein H.; AlMukdad, Sawsan; Faust, Jeremy S.; Tang, Patrick; ... more authors (2023 , Article)
      In October of 2022, Qatar introduced COVID-19 bivalent vaccination for persons ≥ 12 years using the 50-μg mRNA-1273.214 vaccine combining SARS-CoV-2 ancestral and omicron BA.1 strains.1 We estimated this vaccine’s effectiveness ...

    • 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 ...

    • BNT162b2 Versus mRNA-1273 Vaccines: Comparative Analysis of Long-Term Protection Against SARS-CoV-2 Infection and Severe COVID-19 in Qatar 

      Chemaitelly, Hiam; Ayoub, Houssein H; Coyle, Peter; Tang, Patrick; Hasan, Mohammad R; ... more authors ( Wiley , 2024 , Article)
      Background: This study provides a head-to-head comparison of the protection provided by the BNT162b2 and mRNA-1273 vaccines against SARS-CoV-2 infection and against severe COVID-19, covering primary series and third ...

    • 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 ( Edinburgh University Global Health Society , 2022 , Article)
      Background The effective reproduction number, Rt, is a tool to track and understand pandemic dynamics. This investigation of Rt estimations was conducted to guide the national COVID-19 response in Qatar, from the onset of ...

    • Characterizing the Qatar advanced-phase SARS-CoV-2 epidemic 

      Abu-Raddad, Laith J.; Chemaitelly, Hiam; Ayoub, Houssein H.; Al Kanaani, Zaina; Al Khal, Abdullatif; ... more authors ( springer nature , 2021 , Article)
      The overarching objective of this study was to provide the descriptive epidemiology of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic in Qatar by addressing specific research questions through a ...

    • Characterizing trends and associations for hepatitis C virus antibody prevalence in the Middle East and North Africa: meta-regression analyses 

      Mahmud, Sarwat; Chemaitelly, Hiam; Alaama, Ahmed S.; Hermez, Joumana G.; Abu-Raddad, Laith J. ( Springer Nature , 2022 , Article)
      This study characterized population-level trends and associations with hepatitis C virus (HCV) antibody (Ab) prevalence in the Middle East and North Africa (MENA). Data source was the standardized and systematically gathered ...

    • Comparative analysis and evolution of civilian versus combatant mortality ratios in Israel-Gaza conflicts, 2008–2023 

      Ayoub, Houssein H.; Chemaitelly, Hiam; Abu-Raddad, Laith J. ( Frontiers Media SA , 2024 , Article)
      Background: There is a need for statistical methodologies that scrutinize civilian casualties in conflicts, evaluating the degree to which the conduct of war affects civilians and breaches the laws of war. Employing an ...

    • Coronavirus Disease 2019 Disease Severity in Children Infected With the Omicron Variant 

      Butt, A.A.; Butt, Adeel A.; Dargham, Soha R.; Loka, Srusvin; Shaik, Riyazuddin M.; ... more authors ( NLM (Medline) , 2022 , Article)
      SHORT SUMMARY: Severe acute respiratory syndrome coronavirus 2 infection from the Omicron variant in children/adolescents is less severe than infection from the Delta variant. Those 6 to <18 years also have less severe ...

    • Covid-19 Vaccine Protection among Children and Adolescents in Qatar. 

      Chemaitelly, Hiam; AlMukdad, Sawsan; Ayoub, Houssein H; Altarawneh, Heba N; Coyle, Peter; ... more authors ( Massachusetts Medical Society , 2022 , Article)
      The BNT162b2 vaccine against coronavirus disease 2019 (Covid-19) has been authorized for use in children 5 to 11 years of age and adolescents 12 to 17 years of age but in different antigen doses. We assessed the real-world ...

    • Differential protection against SARS-CoV-2 reinfection pre- and post-Omicron 

      Chemaitelly, Hiam; Ayoub, Houssein H.; Coyle, Peter; Tang, Patrick; Hasan, Mohammad R.; ... more authors ( Springer Nature , 2025 , Article)
      The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly evolved over short timescales, leading to the emergence of more transmissible variants such as Alpha and Delta1, 2–3. The arrival of the Omicron ...

    • 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 ...

    • Dynamics of Neisseria gonorrhoeae transmission among female sex workers and clients: A mathematical modeling study 

      Houssein H., Ayoub; Tomy, Milan; Chemaitelly, Hiam; Omori, Ryosuke; Buse, Kent; ... more authors ( Elsevier , 2024 , Article)
      BackgroundThis study aimed to examine the transmission dynamics of Neisseria gonorrhoeae (NG) in heterosexual sex work networks (HSWNs) and the impact of variation in sexual behavior and interventions on NG epidemiology. ...

    • 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 ...

    • Effectiveness of influenza vaccination against SARS-CoV-2 infection among healthcare workers in Qatar 

      Elias, Tayar; Abdeen, Sami; Abed Alah, Muna; Chemaitelly, Hiam; Bougmiza, Iheb; ... more authors ( Elsevier , 2023 , Article)
      BackgroundSome studies have reported that influenza vaccination is associated with lower risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and/or coronavirus disease 2019 (COVID-19) morbidity ...