Research purpose: The research aims to estimate the prevalence of detectable SARS-CoV-2 antibodies, T and B memory cells after recovery, to determine the prevalence of SARS-CoV-2 reinfection, and to investigate the protective ...

We aimed to estimate, albeit crudely and provisionally, national, regional, and global proportions of respective populations that have been infected with SARS-CoV-2 in the first year after the introduction of this virus ...

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 ...

We read with interest the work of COCOREC (Collaborative study COvid RECurrences) study group.1 Recurrent positive rt-PCR results for SARS-CoV-2 infection were reported from early in the epidemic.1 , 2 , 3 , 4 , ...

ObjectivesTo estimate the real-world effectiveness of sotrovimab against severe, critical, or fatal COVID-19 in Qatar at a time in which most SARS-CoV-2 incidences occurred due to the BA.2 Omicron subvariant. MethodsWe ...

Different COVID-19 treatment candidates are under development, and some are becoming available including two promising drugs from Merck and Pfizer. This study provides conceptual frameworks for the effects of three types ...

Background Statins up-regulate angiotensin converting enzyme-2, the receptor of SARS-CoV-2, while also exhibiting pleiotropic antiviral, antithrombotic and anti-inflammatory properties. Uncertainties exist about their ...

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 ...

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 ...

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 ...