asked the Secretary of State for Social Services when he expects the new whooping cough vaccine produced at Porton Down to go on to the market; and what tests, and on whom, will be performed beforehand.

The vaccine is currently undergoing laboratory tests at the National Institute for Biological Standards and Control. Clinical trials will then be carried out initially on adults and, if satisfactory, on children. It is not possible to say at this stage when the new vaccine will be marketed.