A tale of two experts: thalidomide and political engagement in the United States and West Germany.

The physicians, Widukind Lenz and Frances Kelsey, played crucial roles in the thalidomide drama of the early 1960s. Widespread use of the drug in West Germany was only halted when the paediatrician, Lenz, publicized its association with the birth of nearly 4,000 children exhibiting abnormal limb growth. Few cases were reported in the United States because Kelsey, a medical officer at the US Food and Drug Administration, repeatedly delayed thalidomide's marketing approval. Experts in both countries were expected to demonstrate publicly the professional 'objectivity' of medicine and the institutional 'disinterestedness' of regulatory bodies. These norms were invoked both by industry representatives seeking to undermine the two experts and by critics desiring stronger regulatory controls. Comparing Lenz and Kelsey demonstrates how institutional structures shape an expert's social and scientific roles. While the United States provided important protection from external pressure for Kelsey through her regulatory position at the FDA, Lenz was open to sharp criticism, especially when giving expert testimony during a lengthy court trial. The degree of exposure to politically motivated attacks differed for these two experts; they nevertheless faced similar threats to their professional credibility and personal integrity when they publicized links between thalidomide and birth defects.