Characterisation of T-cell Response to Keyhole Limpet Hemocyanin (KLH) and Tuberculin Purified Protein Derivative (PPD)

KLH will be administered as single ID injection of 0.1 mg as 0.1mL of KLH (1 mg/mL)

KLH will be administered as single SC injection of 5 mg

PBS will be administered in Part A on Day 1 as 3 ID injections and in Part C: Cohort 1 on Day 1 and Day 2 as a single ID injection

Tuberculin PPD will be administered in Part B Cohort 2 on Day 1 as single ID injection of 2TU (0.04 microg/mL) in each forearm. In Part C Cohort 2 PPD will be administered on Day 1 as a single ID injection of 2TU. On day 3, if the induration is 6 mm or more; 2 ID injections of 2 TU will be administered on Day 29 in Part B Cohort 2 and 1injection of 2TU on Day 29 in Part C Cohort 2. On day 3, if the induration is less than 6 mm, subject will be re-challenged with 10 TU (0.04 microg/mL) PPD followed by 2 ID injections of 10 TU on Day 29 in Part B Cohort 2 or 1 ID injection of 10TU on Day 29 in Part C Cohort 2.