Boost for Covid testing

RESEARCH: FASTER, LOCALLY PRODUCED KITS ON THE CARDS – CSIR

New method will cut two-step nasal and throat swab into a single step.

Faster and locally produced Covid-19 test kits could be ready for rollout within the next few months, the Council for Scientific and Industrial Research (CSIR) announced.

CSIR senior researcher Dr Lusisizwe Kwazi has been working on a one-step kit, which could be ready for “national roll-out within six months”, depending on approval from the SA Health Products Regulatory Authority.

The current two-step nasal and throat swab tests for Covid-19 test, for the presence of severe acute respiratory syndrome coronavirus 2 (Sars-CoV-2) through polymerase chain reaction testing, take longer to get results.

CSIR said the virus’ first genetic material – its RNA – has to be converted to DNA using an enzyme called reverse transcriptase, in a reaction called RT-PCR.

PCR was then used to make thousands of copies of the DNA until there was enough of the tiny molecules to detect.

“If the test detects the targeted DNA copies, there must have been viral RNA in the sample, hence the test is positive.”

The research council said it had already established highly efficient technology to produce the enzyme, which was necessary for the second step.

“This enzyme is known as DNA Tag polymerase. Only three grams of the protein produced in

E.coli bacteria in as little as three days, is enough for a billion PCR reactions,” Kwezi said.

He, however, cautioned that it did not equate to Covid-19 tests for a billion people as, among other technical reasons, diagnostic tests had to be repeated several times to ensure the accuracy of the results for each patient. Kwezi added that a three-gram batch was delivered to CapeBio Technologies by the CSIR. The local company had licensed and commercialised the technology. It would be rolled out to support the national testing effort once CapeBio got approval.

“Thanks to funding just awarded through the strategic health innovation partnership – a partnership between the South African Medical Research Council and the department of science and innovation – the CSIR and CapeBio are now working to add the reverse transcriptase enzyme to the mix as well, so that the twostep Covid-19 PCR test can be done in a single step.

“This will reduce the turnaround time of tests.”

Meanwhile, it was announced that South Africa was in the process of finalising a R25-million investment to boost Pan-African Covid-19 vaccine manufacturing capabilities.

Minister of Higher Education, Science and Technology Blade Nzimande revealed that South African researchers were working in collaboration with international vaccine developers around a potential Covid-19 vaccine.

“The South African Medical Research Council and the department of science and innovation have provided R10 million funding for the first South African Covid-19 vaccine trial.

This will reduce the turnaround time of tests