CureVac said its COVID-19 vaccine was 48 percent effective in the final analysis of its pivotal mass trial, only marginally better than the 47 percent reported after an initial read-out two weeks ago. The German biotech firm said that efficacy, measured by preventing symptomatic disease, was slightly better at 53 percent when excluding trial participants older than 60 years, an age group that is by far the most severely affected. CureVac said on June 16 its COVID-19 vaccine, known as CVnCoV, proved 47 percent effective in an initial trial read-out and that new variants had proved a headwind, denting investor confidence in its ability to take on rival shots. That wiped billions of euros from its market value. Wednesday’s news sent U.S.-listed shares of the company 10.2 percent lower to $66 after the bell. Late-stage trials of BioNTech/Pfizer and Moderna vaccines, which like CureVac’s are based on mRNA technology, had …