At the beginning of 2018 i was vaccinated which is rabies.2 days ago i was scratched by cat is the rabies vaccine necessary again?

Some basics: The primary series of rabies shots is thought to confer immunity for 2 years after dose. However, due to the severity of the disease, most centers will give a booster after any valid exposure to a rabid animal. Your local health department keeps tabs on whether or not there is rabies active in your region & which animals may be carriers. I would call them & confer with them for this answer.