Monoclonal antibodies binding UL16 and UL141, two viral proteins that are expressed early after infection and before vFcγR levels rise, mediated ADCC against Merlin-infected cells when the Fc domain was modified with S239D and I332E changes to increase CD16A affinity to 2 nM62 without impacting vFcγR capture. Here, FCGR3A is linked to infection.