10 July 2015
Vol 349, Issue 6244

About The Cover

Cover image expansion

COVER A goal in HIV research is to design a vaccine that will protect against the rapidly mutating virus. Such a vaccine would elicit B cells to produce broadly neutralizing antibodies with a high affinity for the HIV envelope protein. Pictured here are B cells displaying colored antibodies; B cells in the foreground express unmutated antibodies of varying specificities. Over time, the right mutations take place to create the lineage of the sought-after antibody (lineage depicted by orange-red gradient, with the unmutated ancestor depicted in orange). This happens in some HIV patients naturally, but now scientists have immunized animals with engineered immunogens that prime a first step on the antibody mutation pathway. See pages 139 , 154, and 156.
Illustration: Valerie Altounian/Science