Ticks don't thrive in Winters so they go into hibernation mode in cold climate. Ticks and flees thrive well in warmer climatic conditions. The ticks that you see around you are now leaving your dog's body which is a good sign. You don't really have to do anything as these creatures don't really pose a serious threat to human-beings. Whenever, you see any, just get rid off them by killing them.
To ensure your dog is equipped well against ticks as you have a tick-infected dog in your area, you can tie anti-tick collar on his neck. You can buy it from your local Vet. Brush your dog regularly with tick brush and bath him with a good anti-tick shampoo. As your dog is infected you need to shampoo him weekly. Do use warm water and make sure your dog's coat is thoroughly dried up with towel.
Frontline is a tick shampoo. It has good customer reviews and you can go for it. Tick injections is to cure tick-fever and if your Vet suggests it, you can go for that treatment.
Keep your dog in leash and don't allow him to play with infected dogs.