About a promising new HIV vaccine, hear that the United Arab Emirates will become the first Arab nation to launch a planetary-science mission and discover a plot twist in the tale of the placental microbiome.

Scientists have been trying for decades to develop an effective vaccine against HIV (virus particles shown in blue). (Steve Gschmeissner/SPL)

‘Mosaic’ HIV vaccine trial set to begin An experimental HIV vaccine that promises the longest-lasting protection so far will start a late-stage clinical trial later this year. More than 100 HIV vaccines have been tested in people in the past three decades, but only one has demonstrated any kind of protection, which waned within a year. One of the biggest challenges is the huge diversity of HIV strains circulating in the world. The new vaccine contains a disabled common-cold virus that carries synthetic HIV genes and proteins based on lots of strains from around the globe. Nature | 4 min read