Scientists have for the first time highlighted a new type of antibody called immunoglobulin G3 (IgG3) that stops the immune system's B cells from doing their normal job of fighting pathogens in certain people living with HIV. This phenomenon appears to be one way the body tries to reduce the potentially damaging effects of immune-system hyperactivity caused by the presence of HIV according to the investigators but in so doing it also impairs normal immune function. The investigators made their discovery by analysing blood samples from 83 HIV-uninfected anonymous donors and 108 people who were living with HIV at various