Had sore or strep throat for a week. how soon could i get strep throat again?

Any Time: We build very little natural immunity to strep, so once the antibiotic is out of your system, you can be infected again.

Anytime: As soon as you come off antibiotics & they clear your system, you become available for a new infection. Most acquire strep though active or passive exposure to infected saliva, either at home, school or workplace. Exposure and disease is somewhat random unless you have a strep carrier in your extended household.