Coronavirus vaccine trials have delivered their first results — but their promise is still unclear

Tests of other fast-tracked vaccines show that they have prevented infections in the lungs of monkeys exposed to SARS-CoV-2 — but not in some other parts of the body. One — a vaccine being developed at the University of Oxford, UK, that is also in human trials — protected six monkeys from pneumonia, but the animals’ noses harboured as much virus as did those of unvaccinated monkeys, researchers reported1 last week in a bioRxiv preprint. A Chinese group reported similar caveats about its own vaccine’s early animal tests this month. Nature