Though the news was not entirely unexpected, we regret to report that the breakthrough vaccine promised by CureVac will now not be forthcoming. There are a number of reasons for this, but the main factor was the high demands that CureVac itself placed on the product. The aim was to develop a vaccine that was as natural as possible – ideally the most natural vaccine to date. In the end, it was the much-debated issue of vaccine-induced side-effects and long-term effects that thwarted their endeavor.