Abstract
With this article by Nobel laureate Rolf Zinkernagel, the Immunology series that began in July 2000 comes to an end. Zinkernagel's thesis concerns the influence of a mother's immunologic memory on the effectiveness of childhood vaccination and the susceptibility of her child to infectious diseases. He reviews how immunity in the entire community (herd immunity) affects immune protection not only in the mother but also in succeeding generations. Zinkernagel warns that lax vaccination programs and complacency produced by improved living standards will have global effects on susceptibility to infection and autoimmune diseases.