The ability to rapidly and accurately determine the viral infectivity and oncolytic effects of drug candidates could help improve the speed of oncolytic vaccine R&D, product development, manufacturing, and efficacy monitoring. Here we present the results from monitoring T-VEC infection in melanoma cancer cells using Laser Force Cytology™. LumaCyte’s Radiance® instrument develops an infection metric that correlates well with the initial virus concentration, demonstrating the potential for rapid infectivity and oncolytic measurements using LFC ™.  In addition, through the use of multivariate analysis using LFC ™ data, cells infected with T-VEC and treated with a MEK inhibitor can be differentiated from cells treated with only T-VEC, demonstrating the ability of LFC ™ to capture subtle cellular changes.