The German company CureVac announced on Wednesday the final results of its late-stage vaccine trial, confirming earlier data showing that its shot is far less protective than other vaccines.
Overall, the CureVac vaccine had an efficacy of just 48 percent against Covid-19. The Moderna and Pfizer-BioNTech vaccines, which use the same mRNA technology as CureVac’s, delivered efficacy rates around 95 percent in clinical trials.
CureVac’s vaccine proved somewhat better for younger volunteers: For those between the ages of 18 and 60, the efficacy rose to 53 percent. In that group, the researchers also found the vaccine provided 100 percent protection against hospitalization and death.
Forty thousand people participated in the company’s trial in Europe and Latin America. By the end of the study, 288 volunteers had gotten Covid-19.
CureVac had to contend with 15 different variants of the coronavirus. Genetic testing showed that only 3 percent of the cases were caused by the original version of the coronavirus. It’s possible that some of the variants were able to evade the immunity provoked by the CureVac vaccine. (No variants had become widespread in 2020 when Moderna and Pfizer-BioNTech ran their trials.)
But vaccine experts have also questioned whether part of CureVac’s problem was with the design of the vaccine itself. The precise recipe that CureVac used to build its vaccine may have blunted its effectiveness.
The European Medicines Agency opened a rolling review of CureVac’s vaccine in February, and the company said it would continue its submission with these data. The vaccine “will be an important contribution to help manage the Covid-19 pandemic and the dynamic variant spread,” Franz-Werner Haas, the chief executive of CureVac, said in the announcement.