Can the Influenza viruses be transmitted through food? Such as eating a takeaway food.

Okay so there is like a magic sentence that gets said when somebody is talking about black holes "it is so dense and its gravity so large not even light can escape it" But if fotons have no mass then how can they be pulled in? If we know that a=mg then if mass is zero then the acceleration of the light towards the black hole should equal 0 no matter what