Plz go through all point. Become rabid!

My dog is vaccinated and always being a house dog. 1 stray dog came inside our room after chasing my dog where he managed to hide before it came. That stray dog died after 28days .reason unknown. He never bite anyone not even my dog. Just for mental peace we gave him full 5course vaccination of ARV but after 3months of that incident. After the completion  of course another 3 months has been passed and my dog is still healthy and happy.. my family member are also vaccinated with pre exposure vaccination 3doses. My dog always licks and play scratch us.he never bite us till date for last 2years since he was puppy .Can we simply watch him for 10days to starts PEP if any unfortunate event would happen in future. Cz we think it is absurd to take arv as booster in every 3months without any cause for coming 10years atleast. 1.stray dog died after 28days 2.stray was not drooling biting anyone and was not observed for any bizzare behaviour for 16days. 3. after 7months no other dog become rabid