A Swiss International Airlines Airbus A321-200, registration HB-IOC performing flight LX-1077 from Frankfurt/Main (Germany) to Zurich (Switzerland), was intercepting the ILS for Zurich's runway 28 when the crew declared Mayday reporting one of the pilots was incapacitated possibly due to food poisoning. The aircraft continued for a safe landing on runway 28, the aircraft taxied to the gate with emergency services in trail.