Air carrier flight crew reported a fumes event that was described as 'dirty socks' odor during departure taxi. Flight crew returned to departure gate where paramedics met the aircraft.

Narrative

During taxi to Runway XXR after both engines were running and the APU was off; the AFT Flight Attendant called and said she could smell 'dirty socks'. I asked her how intense the smell was on a scale of 1-10 and she said it was a 6-7. There was no visible smoke. I returned to the Gate immediately after shutting down the number 2 engine and taxiing on only the number 1 engine. I requested paramedics meet us at the Gate. I did not restart the APU and we waited for ground power to be hooked up before shutting number 1 down. The smell dissipated rapidly once we got to the Gate. One Flight Attendant was taken to the hospital with symptoms of nausea; headache; blurry vision and red eyes. Odor was only detected from over wing aft. We did not smell it in the cockpit and were both unaffected. The forward FA was unaffected. The other FA; although smelling the odor was also unaffected. This aircraft had a reported odor event the day prior as well. Dirty Sock Smell throughout the aft cabin. The company and all personnel handled the event professionally and proficiently.