… Reinfection was defined as a PCR positive result in … SARS-CoV-2 antibody-positive
persons in Qatar with at least one PCR-positive swab that occurred ≥14 days after the first-positive …

… from SARS CoV2 infection, we found that a positive result on the LFIA used in the REACT
2 antibody prevalence study was associated with a higher titre of neutralising antibody. Sera …

… Likewise, it is possible that seropositive individuals might be less likely to seek
evaluation for subsequent symptoms of COVID-19, but, in fact, we observed that antibody-positive …

… Main Outcomes and Measures SARS-CoV-2 antibody positivity … SARS-CoV-2 IgG level, total
antibody (TAb) level, surrogate … We compared the SARS-CoV-2 IgG levels from 85 positive …

… of subsequent positive SARS-CoV-2 polymerase-chain-reaction (PCR) tests and symptomatic
infections in health care workers who were seropositive for SARS-CoV-2 antibodies and …

… to either nucleocapsid (N) or spike (S) proteins performed on specimens from 39,086
individuals with confirmed positive COVID-19 by reverse transcription-polymerase chain reaction (…

… SARS-CoV-2 PCR-positive study nose/throat swab or anti-spike IgG-positive study antibody
… to have been previously infected with SARS-CoV-2, irrespective of whether they had …

… SARS-CoV-2 PCR testing was available, only 34% of the antibody positive cohort had a
documented positive … maximum positive antibody test rather than time from first positive PCR or …

… that were positive by the qualitative Roche anti-SARS-CoV-2 assay … -SARS-CoV-2 antibody
assay to determine specific antibody titer, it is important to note that the majority of positive …

… recovered from COVID-19 are protected from future SARS-CoV-2 infection is an urgent
requirement. We aimed to investigate whether antibodies against SARS-CoV-2 were associated …