University of Helsinki has tested the capability of COVIDSAFE to inactivate SARS-coronavirus-2. The testing was performed in a biosafety-level-3 (BSL-3) laboratory with live SARS-CoV-2 from a cultured virus sample. The virus sample was applied on the COVIDSAFE surface as well as control materials, and allowed to air-dry in room temperature for 1 to 30 minutes. After this incubation time, a sample from the virus was added to susceptible cultured cells and the virus viability was tested by allowing virus to infect the cells for the duration of at least 5 days. During this time, if the virus is viable, it will cause a visible cytopathic effect on the cultured cells. Additionally, all samples were checked with qRT-PCR to measure the level of viral RNA copies (relative quantitation). The results are given as qRT-PCR Ct-values (a low value equals high amount of virus RNA). No CPE is observed when the Ct-value is >30 meaning that no infectious particles are present.
Together these findings may be taken to show that in the conditions tested, COVIDSAFE inactivates the virus in less than a one minute contact time.
On a used surface, viral RNA is still detected at 1 minute, but this likely represents noninfectious particles as no CPE was observed in the cell culture.
It should be noted however, that the test result may not be the same if tested using other incubation times or conditions. It should also be noted that the virus concentration tested here is considerably higher than those typically observed in non-laboratory conditions. This was done in order to give the surface material a maximum? challenge in this test.
Tarja Sironen, PhD
Associate Professor of Emerging infections
Faculties of Medicine and Veterinary Medicine
University of Helsinki