There is a sick kitty the n my neighborhood. I m allergic. I feed him every day and even had him vaccinated and fixed. He's not putting on any weight. What to do?

If the cat is eating but not gaining needed weight, then something is probably wrong and will need attention. It might just need a higher protein diet. Or it may have a health issue. In either case, I'd get the cat checked out. If there's a financial issue with accomplishing that, I believe BARCs has a list of organizations that offer assistance/grants to pay for any needed care.

Call them and see if they can help you?