Summary
The startlingly poor performance revealed last week for a COVID-19 vaccine made by the German company CureVac isn’t just a disappointment, it’s a scientific puzzle. The company blames the rapidly changing pandemic virus. But several outside researchers suspect the vaccine’s design is at fault.┬аMany scientists and investors alike had expected CureVac’s candidate, which uses messenger RNA (mRNA) to code for the spike surface protein of SARS-CoV-2, had a good chance of becoming one of the most powerful new weapons against the pandemic. It relies on essentially the same novel mRNA technology as vaccines from the Pfizer-BioNTech collaboration and Moderna, which demonstrated more than 90% efficacy in their trials, and it holds some practical transportation and storage advantages over those rival shots. But interim results from a large clinical trial found it only offered 47% efficacy.
