Evaluation of Silverlab Healthcare’s ionic⁺ Colloidal Silver Disinfectant Effectiveness Against SARS-CoV-2  

In late 2019 several individuals were hospitalized in Wuhan in China with what appeared to be cases of severe respiratory illnesses (Kannan et al., 2020). The disease was called the 2019 coronavirus disease (COVID-19) and the etiological agent was the coronavirus2 or SARS-CoV-2 (Nie et al., 2020; van Doremalen et al., 2020). One of the main routes of transmission of this virus is through contaminated aerosols resulting from coughing or sneezing for example (Kannan et al., 2020).  

The virus incubation time in an infected individual is 2 to 14 days. However, even asymptomatic infected people can effectively spread SARS-CoV-2. Most COVID-19 cases or 80% is either asymptomatic or have only mild symptoms. However, 20% of all those infected will develop severe illness with the mortality rate standing at about 5% across the globe. So far globally there are over 219 million individuals infected with SARS-CoV-2 and nearly 4.55 million deaths (WHO, 2021).  

Early 2020 the World Health Organization (WHO) declared COVID-19 a global pandemic. COVID-19 has affected millions of people and caused many deaths in the world, most developed and industrialized countries; as well as taking many economies into recessions or at the brink of collapse. 

Since the start of the pandemic, scientists around the world instigated research in the quest to finding vaccines that can be used to prevent the spread of the virus. Late 2020 and early 2021, several vaccines were approved, namely, Johnson & Johnson, Pfizer and AstraZeneca vaccines to name only few.  

They are currently being administered around the world as a way of controlling the virus. Other ways of preventing SARS-CoV-2 infection is by disinfecting all exposed surfaces with detergents, sanitizers, soaps and so on. However, there are many products in the market that are claimed to be active against SARS-CoV-2 without any proof of such. It is in this context that Silverlab Healthcare contacted the CSIR with a disinfectant for evaluation against SARS-CoV-2.  

The virus used in the evaluation was generated in 293- T cells by co-transfection of a construct carrying the SARS-CoV-2 envelope and a plasmid encoding the luciferase reporter gene. This was followed by the determination of the virus tissue culture infectious dose 50 (TCID50) before treatment with the disinfectant. In summary the Silverlab Healthcare disinfectant achieved log 3 and 4 reductions against SARS-CoV-2 in 293T-ACE cells when exposed for 30 and 60 seconds respectively, see Table 1. Figure 1 shows the plot of SARS-CoV-2 infectivity in the absence of the disinfectant, while Figures 2 and 3 show the virus infectivity in the presence of Silverlab Healthcare disinfectant for 30 and 60 seconds, respectively.