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Population immunity of natural infection, primary-series vaccination, and booster vaccination in Qatar during the COVID-19 pandemic: an observational study
(
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 ...
Bivalent mRNA-1273.214 vaccine effectiveness against SARS-CoV-2 omicron XBB* infections
(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 ...
Long-term COVID-19 booster effectiveness by infection history and clinical vulnerability and immune imprinting: a retrospective population-based cohort study
(
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 ...
Turning point in COVID-19 severity and fatality during the pandemic: a national cohort study in Qatar
(
BMJ Publishing Group
, 2023 , Article)
Objective To assess the evolution of COVID-19 severity and fatality in a unique setting that consistently applied, throughout the pandemic, rigorous and standardised criteria for defining severe COVID-19 outcomes.
Methods ...
SARS-CoV-2 infection and effects of age, sex, comorbidity, and vaccination among older individuals: A national cohort study
(
Wiley
, 2023 , Article)
Background: We investigated the contribution of age, coexisting medical conditions, sex, and vaccination to incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and of severe, critical, or ...
Effectiveness of two and three doses of COVID-19 mRNA vaccines against infection, symptoms, and severity in the pre-omicron era: A time-dependent gradient
(
Elsevier
, 2024 , Article)
BackgroundVaccines were developed and deployed to combat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aimed to characterize patterns in the protection provided by the BNT162b2 and ...
Waning mRNA-1273 Vaccine Effectiveness against SARS-CoV-2 Infection in Qatar
(
Massachussetts Medical Society
, 2022 , Other)
In early 2021, Qatar launched a mass immunization campaign with the mRNA-1273 (Moderna)1 vaccine against coronavirus disease 2019 (Covid-19).2 We assessed the persistence of real-world vaccine effectiveness against severe ...
Protection of natural infection against reinfection with SARS-CoV-2 JN.1 variant
(
Oxford University Press
, 2024 , Article)
Evidence at the level of neutralizing antibodies suggests that the SARS-CoV-2 JN.1 variant demonstrates increased immune evasion compared to its parent lineage BA.2.86 and to recently circulating variants, such as XBB.1.5 ...
BNT162b2 Versus mRNA-1273 Vaccines: Comparative Analysis of Long-Term Protection Against SARS-CoV-2 Infection and Severe COVID-19 in Qatar
(
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 ...
Protection conferred by SARS-CoV-2 infection across a spectrum of reinfection symptoms and severities
(
BMJ Publishing Group
, 2025 , Article)
Background SARS-CoV-2 infection is associated with protection against reinfection. This study analysed this protection across different reinfection symptoms and severities, comparing the preomicron and omicron eras. Methods ...