Development and evaluation of a Novel RT‐PCR system for reliable and rapid SARS‐CoV‐2 screening of blood donations

Abstract

Background The ongoing outbreak of SARS‐CoV‐2 has caused great global concerns. In contrast to SARS, some SARS‐CoV‐2 infected people can be asymptomatic or only have mild non‐specific symptoms. Furthermore, there is evidence that SARS‐CoV‐2 may be infectious during an asymptomatic incubation period. With the discovery that SARS‐CoV‐2 can be detected in plasma or serum, blood safety is worthy of consideration. Study design and Methods We developed a NAT screening system for SARS‐CoV‐2 targeting nucleocapsid protein (N) and open reading frame 1ab (ORF 1ab) gene which could screen 5076 samples every 24 hours. 2019‐nCoV RNA standard was used to evaluate linearity of standard curves. Diagnostic sensitivity and reproducibility were evaluated using artificial SARS‐CoV‐2 virus. Specificity was evaluated with 61 other respiratory pathogens. Diagnostic performance was evaluated by testing 2 sputum and 9 oropharyngeal swab specimens. The RT‐PCR assay was used to screen SARS‐CoV‐2 RNA in blood donors specimens collected during the outbreak of SARS‐CoV‐2 in Chengdu. Results LOD of the SARS‐CoV‐2 RT‐PCR assay for N and ORF 1ab gene were 12.5 and 27.58 copies/mL, respectively. Intra‐assay and inter‐assay for SARS‐CoV‐2 RT‐PCR assay based on Ct were acceptably low. No cross‐reactivity was observed with other respiratory virus and bacterial isolates. The overall agreement value between SARS‐CoV‐2 RT‐PCR assay and clinical diagnostic results were 100%. A total of 16 287 blood specimens collected from blood donors during SARS‐CoV‐2 surveillance were tested negative. Conclusions A high throughput NAT screening system was developed for SARS‐CoV‐2 screening of blood donations during the outbreak of SARS‐CoV‐2.

Validation of a SARS‐CoV‐2 RNA RT‐PCR assay for high‐throughput testing in blood of COVID‐19 convalescent plasma donors and patients

“…The higher frequency of SARS‐CoV‐2 RNA detection in the study of the Wuhan Blood Center could be related to differences in the sensitivity of pooled‐sample testing and in the time period of donation testing, which was performed closer to height of the outbreak of SARS‐CoV‐2 in Wuhan compared to the multicenter study in Hubei province 13 . However, another study in over 16 000 blood donors during the outbreak in Chengdu did not detect SARS‐CoV‐2 RNA in blood by testing in minipools of six samples (LOD for the N region, 12.5 copies/mL for single‐ and 75 copies/mL for pooled‐sample testing) 14 …”

Novel neutralizing chicken IgY antibodies targeting 17 potent conserved peptides identified by SARS-CoV-2 proteome microarray, and future prospects

“…The results from the FRNT assay confirmed the RT-PCR assay. The novel N-IgY-pAb “intranasal spray” at 3 μg/mL (2x dilution, Figures 4A, B ) responded against the wild type of the SARS-CoV-2 virus, the variants of Delta and Omicron, corresponding to the neutralizing rate of ≥ 95% ( 22 ). It implied that the “intranasal spray” containing 6μg/ml of N-IgY-pAb could be adequate to neutralize the virus effectively.…”

“…The data were plotted after background subtraction and normalized to the controls. The virus-neutralizing effect was accepted when the neutralizing rate was ≥ 95% ( 22 ).…”

“…The neutralizing ratio = (1-the spots in well with N-IgY-Ab/the spots in well without N-IgY-Ab) x100%. The virus-neutralizing effect was accepted when the neutralizing rate was ≥ 95% ( 22 ).…”

Blood scarcity at the blood banks during COVID-19 pandemic and strategies to promote blood donations: current knowledge and futuristic vision

“…Screening tests have some limitations and are not fully met at the donor or blood donation level. More recently, a novel RT-PCR system targeting SARS-CoV-2 nucleocapsid protein (N) and open reading frame 1ab (ORF 1ab) has been reported to be developed for confirmatory and quick screening of SARS-CoV-2 in blood donor specimens [31,32]. Optimum safety checkpoints need to be followed to ensure that the transfused blood is not contaminated with SARS-CoV-2.…”