Browsing by Author "Latif, Ali Nizar"

Now showing items 1-20 of 25

    • 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 ...

    • 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 ...

    • 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 ...

    • 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 ...

    • 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 ...

    • Duration of COVID-19 mRNA Vaccine Effectiveness against Severe Disease 

      Bansal, Devendra; Abdulmajeed, Jazeel; Al-Shamali, Maha H.M.A.; Albayat, Soha S.A.; Himatt, Sayed M.; ... more authors ( MDPI , 2022 , Article)
      Waning immunity following administration of mRNA-based COVID-19 vaccines remains a concern for many health systems. We undertook a study to determine if recent reports of waning for severe disease could have been attributed ...

    • 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 ...

    • 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 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 ...

    • Mathematical modeling of the SARSCoV-2 epidemic in Qatar and its impact on the national response to COVID-19 

      Ayoub, Houssein H.; Chemaitelly, Hiam; Seedat, Shaheen; Makhoul, Monia; Kanaani, Zaina Al; ... more authors ( University of Edinburgh , 2021 , Article)
      Background Mathematical modeling constitutes an important tool for planning robust responses to epidemics. This study was conducted to guide the Qatari national response to the severe acute respiratory syndrome coronavirus ...

    • 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 ...

    • Pfizer-BioNTech mRNA BNT162b2 Covid-19 vaccine protection against variants of concern after one versus two doses. 

      Abu-Raddad, Laith J; Chemaitelly, Hiam; Yassine, Hadi M; Benslimane, Fatiha M; Al Khatib, Hebah A; ... more authors ( Oxford University Press , 2021 , Article)
      Strategies for rolling out vaccination against Coronavirus Disease 2019 (Covid-19) varied across countries. A key question is whether delaying administration of the second vaccine dose to vaccinate the largest number of ...

    • 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 ...

    • Protection of Omicron sub-lineage infection against reinfection with another Omicron sub-lineage 

      Chemaitelly, Hiam; Ayoub, Houssein H.; Coyle, Peter; Tang, Patrick; Yassine, Hadi M.; ... more authors ( Nature Research , 2022 , Article)
      There is significant genetic distance between SARS-CoV-2 Omicron (B.1.1.529) variant BA.1 and BA.2 sub-lineages. This study investigates immune protection of infection with one sub-lineage against reinfection with the other ...

    • Relative infectiousness of SARS-CoV-2 vaccine breakthrough infections, reinfections, and primary infections. 

      Abu-Raddad, Laith J; Chemaitelly, Hiam; Ayoub, Houssein H; Tang, Patrick; Coyle, Peter; ... more authors ( Springer , 2022 , Article)
      SARS-CoV-2 breakthrough infections in vaccinated individuals and in those who had a prior infection have been observed globally, but the transmission potential of these infections is unknown. The RT-qPCR cycle threshold ...

    • SARS-CoV-2 antibody-positivity protects against reinfection for at least seven months with 95% efficacy 

      Laith J., Abu-Raddad; Chemaitelly, Hiam; Coyle, Peter; Malek, Joel A.; Ahmed, Ayeda A.; ... more authors ( Elsevier , 2021 , Article)
      Background Reinfection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been documented, raising public health concerns. SARS-CoV-2 reinfections were assessed in a cohort of antibody-positive persons ...

    • SARS-CoV-2 infection hospitalization, severity, criticality, and fatality rates in Qatar 

      Seedat, Shaheen; Chemaitelly, Hiam; Ayoub, Houssein H.; Makhoul, Monia; Mumtaz, Ghina R.; ... more authors ( Nature Research , 2021 , Article)
      The SARS-CoV-2 pandemic resulted in considerable morbidity and mortality as well as severe economic and societal disruptions. Despite scientific progress, true infection severity, factoring both diagnosed and undiagnosed ...