[Actuality of Giuseppe D'Alessandro's contribution to the knowledge of the antigenic structure of Treponema pallidum when syphilis is re-emerging as a public health problem]

The antigenic structure of Treponema pallidum was described in the 1940s and 1950s. The main contributions of Giuseppe D'Alessandro and his collaborators included the description of the external membrane and of the polysaccharide antigen found in the cell wall of the microorganism. Based on new knowledge it has been possible to develop diagnostic tests that are more sensitive and specific than nontreponemal tests, which nevertheless retain their validity in the current re-emergence of syphilis as a public health problem.

How Heidelberger and Avery sweetened immunology

In 1923, a young chemist-turned-microbiologist and his mentor made the startling discovery that bacterial sugars could be targeted by the immune system--a groundbreaking finding that helped launch the field of immunochemistry.

Pneumococcal otitis media and pneumococcal vaccines, a historical perspective

Although pneumococcal otitis media was recognized in the 19th century, the illness stimulated little interest in prophylaxis until recently. Whole cell vaccines of killed pneumococci, developed to prevent pneumonia, were replaced by vaccines of capsular polysaccharides following demonstration of their antigenicity in adults. Failure of the latter to stimulate antibodies in infants and young children and demonstration of the efficacy of capsular polysaccharide-protein conjugate vaccines in preventing infection with Hemophilus influenzae type b has led to the development of polyvalent pneumococcal polysaccharide-protein conjugate vaccines. Preliminary studies have shown them to be highly effective in preventing invasive pneumococcal disease in the first 2 years of life, and studies of their impact on otitis media are currently in progress.