Natural infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) elicits strong protection against reinfection with the B.1.1.7 (alpha),1,2 B.1.351 (beta),1 and B.1.617.2 (delta)3 variants. However, the ...

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 ...

The currently authorized mRNA COVID-19 vaccines, Pfizer-BNT162b2 and Moderna-mRNA-1273, offer great promise for reducing the spread of the COVID-19 by generating protective immunity against SARS-CoV-2. Recently, it was ...

In light of the ongoing coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there remain unanswered questions regarding the humoral immune response and ...

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 ...

Background: Limited commercial LFA assays are available to provide a reliable quantitative measurement of the total binding antibody units (BAU/mL) against the receptor-binding domain of the SARS-CoV-2 spike protein (S-RBD). ...

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 ...

Importance: In the ongoing COVID-19 pandemic, there remain unanswered questions regarding the nature and importance of the humoral immune response against other coronaviruses. Although coinfection of the Middle East ...

Appropriate oral hygiene significantly reduces the possibility of oral infections. However, dental caries and periodontal diseases are major oral health issues causing chronic diseases due to poor oral health. Recently, ...

Background The effective reproduction number, Rt, is a tool to track and understand pandemic dynamics. This investigation of Rt estimations was conducted to guide the national COVID-19 response in Qatar, from the onset of ...