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Protection from previous natural infection compared with mRNA vaccination against SARS-CoV-2 infection and severe COVID-19 in Qatar: a retrospective cohort study
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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 ...
Effects of SARS-CoV-2 Alpha, Beta, and Delta variants, age, vaccination, and prior infection on infectiousness of SARS-CoV-2 infections
(
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 ...
Effects of BA.1/BA.2 subvariant, vaccination, and prior infection on infectiousness of SARS-CoV-2 omicron infections.
(
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 ...
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 ...
Effects of Previous Infection and Vaccination on Symptomatic Omicron Infections.
(
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) ...
Duration of immune protection of SARS-CoV-2 natural infection against reinfection.
(
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 ...
Effects of previous infection, vaccination, and hybrid immunity against symptomatic Alpha, Beta, and Delta SARS-CoV-2 infections: an observational study
(
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 ...
Short- and longer-term all-cause mortality among SARS-CoV-2- infected individuals and the pull-forward phenomenon in Qatar: a national cohort study
(
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 ...