Is My Cat Going to Get Sick?

I have a two-year old male cat that isn't up-to-date on his shots. He is 99% of the time an indoor cat - I let him on my balcony this morning and I heard screeching and here he is with a sparrow in his mouth. I yelled at him and he let the bird go and the bird flew away - is my cat going to get sick. What can I do right now before I get him into the vet this coming week.