Your virgin flight is going to come in to the south satellite, after immigration and customs you will be able to clear security there and then you will likely have to take a train to the A gates in the main terminal for your connecting Delta flight. Depending on the lines at passport control, you might have a little wait but you are definitely going to make it with this window for a connection. In addition since you’re booked on one ticket it doesn’t really matter as they will book you on the next Delta flight if you do you miss it