Cellmid Limited (ASX:CDY) has released results from independent testing of the Wondfo SARS-CoV-2A point of care tests (POCT) by the National Institute of Virology of the Indian Council of Medical Research.
The National Institute of Virology is also a Collaborating Centre for Emerging Viral Infections by the World Health Organization.
Studies have been completed independently from Wondfo on samples and the results are consistent with Wondfo’s study of 596 patient samples earlier this year - underlining the utility of the test in the management of the COVID-19 pandemic.
The study was conducted on 24 individual samples of COVID-19 patients from day-two to day-13 from the onset of symptoms, following confirmation of viral load using nucleotide testing.
Another 12 samples positive for other related and non-related viruses were used as controls for cross-reactivity.
The POCT has detected SARS-CoV-2 antibodies as early as day three from the onset of symptoms and accuracy improved with disease progression.
It has detected antibodies in all but one sample from day four following the onset of symptoms (6% false negatives).
SARS-CoV-2 antibodies have been detected by the POCT in 100% of the samples from day six following the onset of symptoms, or approximately day 12 from exposure.
The control samples positive for other related and non-related viruses, but not for SARS-CoV-2, showed no cross-reactivity, meaning there were no false positives in the study.
The Wondfo Biotech manufactured SARS-CoV-2 point of care test detects antibodies to SARS-CoV-2, the virus which causes the COVID-19 disease.
In addition to China, the test is used in several countries including Germany, Spain and India.
In Australia PCR (polymerase chain reaction) is used as the current gold standard method for the diagnosis of acute COVID-19.
If there is virus in the collected sample PCR is highly accurate, however, the success of sampling depends on the person taking the sample, the patient’s stage in the disease and their individual manifestation.
A recent study by Zhao et al (funded by the Bill and Melinda Gates Foundation) and published in the journal Clinical Infectious Diseases, 2020, showed that RNA-based sampling only detected the virus successfully 67% of the time in the first week after onset of symptoms, falling to 46% in week two.
The study showed that by combining antibody-based screening methods with PCR, detection rates of COVID-19 were improved, even in very early disease.