Scientists wаnt tо determine if using pаrticulаr types оf mоuthwash might serve to prevent or reduce transmission of COVID-19. There are different types of mouthwash on the market which contain different active ingredients including: alcohol, povidone-iodine, cetylpyridinium chloride, hydrogen peroxide, and chlorhexidrine. Scientists studied these in vitro (in the lab using a petri dish) and in vivo (in a person's mouth). In the lab (Experiment 1), scientists mixed mouthwash with COVID viral particles as counted the number of viral particles destroyed or degraded. All of the mouthwashes demonstrated some virucidal activity in the lab, likely by disrupting the viral envelope. Scientists then examined (Experiment 2) the effect of the mouthwashes on the viral load (number of viral particles) in the mouth and throat of subjects. The mouthwashes containing povidone-iodine or cetylpyridinium chloride demonstrated reduced viral load in the mouth/throat after use. Larger studies are needed, but these early results suggest that the use of mouthwashes with certain active ingredients might be effective at reducing transmission of the virus by reducing the amount of virus in the mouth that could be shared via droplets or aerosolized during breathing/speaking. Identify the dependent variable for Experiment 2.