Molly is a 4 year old girl who is seen in the urgent care centre with her mother as she is refusing to eat as she says her mouth is sore. Despite this she is still drinking plenty of fluids. This morning she felt hot to touch but no formal temperature was checked. Observations and systems review is unremarkable. On examination you observe a crop of vesicles on her hard palate and 2 shallow ulcers on her tongue.
Based on her likely diagnosis, which virus is usually implicated?