Background

This in vitro study characterized the efficacy of the Plasma Air 603 at removing aerosolized MS2 Bacteriophage, a surrogate for SARS-CoV-2. The Plasma Air device is designed to reduce airborne bacteria, viruses, and fungal spores in order to decrease infections rates from airborne pathogens.

For this study the Plasma Air device was challenged using aerosolized MS2 bacteriophage which has been historically used as a surrogate for influenza, and is now being considered as a surrogate for coronaviruses such as SARS-CoV-2 due to the size similarity to influenza and RNA genome. This study evaluated the efficacy of the device against aerosolized MS2 bacteriophage in an air duct system installed on the stainless steel bioaerosol chamber. The study consisted of a total of three (3) live bioaerosol trials, and a single (1) bioaerosol control run.

Methods

MS2 bacteriophage was aerosolized into a sealed environmental bioaerosol chamber equipped with an air duct system containing the Plasma Air device. AGI Impinger samples were taken from the chamber in order to quantify the reduction speed and capabilities of the Plasma Air device. AGI impingers were used to sample chamber bioaerosol concentrations, all impinger samples were serially diluted, plated and enumerated in triplicate to yield viable bioaerosol concentration at each sampling point and time. The chamber control trial data was subtracted from the Plasma air trial data to yield net LOG reduction in the chamber for the bioaerosol challenges.

Results

When tested against the MS2 bacteriophage, the Plasma Air 603 device showed a consistent net LOG reduction throughout the testing. The average net LOG reduction went from 0.63 at the 120-minute time point down to 2.24 at the 240-minute time point to end the trial. A net LOG reduction of 2.24 over 240 minutes point indicates the efficacy of this device against the MS2 bacteriophage when compared to a natural reduction rate. A net LOG reduction of 2.24 is equivalent to a 99.39% reduction in viable MS2 bacteriophage. These results indicate that in theory the Plasma Air device would help prevent the spread of airborne infection.