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Reporting of RT-PCR cycle threshold (Ct) values during the first wave of COVID-19 in Qatar improved result interpretation in clinical and public health settings
(
Microbiology Society
, 2022 , Article)
Introduction. The cycle threshold (Ct) value in real-time PCR (RT-PCR) is where a target-specific amplification signal becomes detectable and can infer viral load, risk of transmission and recovery. Use of Ct values in ...
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 ...
Introduction and expansion of the SARS-CoV-2 B.1.1.7 variant and reinfections in Qatar: A nationally representative cohort study
(
Public Library of Science
, 2021 , Article)
Background The epidemiology of the SARS-CoV-2 B.1.1.7 (or Alpha) variant is insufficiently understood. This study’s objective was to describe the introduction and expansion of this variant in Qatar and to estimate the ...
Protection against Reinfection with the Omicron BA.2.75 Subvariant
(
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) ...
BNT162b2 antigen dose and SARS-CoV-2 omicron infection in adolescents
(
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 ...
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 ...
Protective Effect of Previous SARS-CoV-2 Infection against Omicron BA.4 and BA.5 Subvariants.
(
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 ...
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 ...
History of primary-series and booster vaccination and protection against Omicron reinfection
(
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 ...
Prevalence of hepatitis B and C viruses among migrant workers in Qatar.
(
Springer Nature
, 2024 , Article)
Limited data exist on viral hepatitis among migrant populations. This study investigated the prevalence of current hepatitis B virus (HBV) infection and lifetime hepatitis C virus (HCV) infection among Qatar's migrant craft ...