LAUSR

Antibody miniaturization leads to a cyclic peptide that neutralizes influenza viruses Influenza virus is one of the largest public health concerns. There is no universal vaccine, and only a few small-molecule drugs are available for therapy and prevention of influenza virus infection. The surface of this virus has two major proteins: neuraminidase and hemagglutinin (HA). These proteins are targets for antivirals. Although antivirals such as oseltamivir exist that bind neuraminidase, a major reason that there is no small-molecule drug against HA is because most of its surface is highly variable, presenting a moving target for drug development. A major breakthrough in developing universal vaccines and broad therapies came almost a decade ago from the identification of a site of vulnerability on influenza HA revealed through analyses of human broadly neutralizing antibodies (antibodies that are able to bind and neutralize many different influenza subtypes) (1). On page 496 of this issue, Kadam et al. (2) present the design and iterative optimization of a cyclic peptide that targets the vulnerable site on HA. This is the first example of such a small peptidic molecule that can be viewed as an antibody surrogate.