CureVac NV’s vaccine disappointment shows that not every messenger-RNA project will live up to hopes.The German biotech firm made some crucial choices that set its candidate apart.
Although the trial results it published earlier this week aren’t directly comparable, and the proliferation of viral variants has complicated studies since the other shots were tested last year, experts say key differences between the vaccines probably played a major role in CureVac’s weak results.One key element was dosage.
CureVac executives said they probably weren’t using enough mRNA to elicit strong immunity. The low dosing was necessary because the company was using a different type of mRNA from the kind in rival shots, and higher amounts would have raised.