Merck ends its COVID-19 vaccine programme after disappointing early trial results

Merck & Co (MSD) has ended its COVID-19 vaccine programme after reviewing some disappointing phase 1 results for its candidates V590 and V591. Although both V590 and V591 were generally well-tolerated in the phase 1 trials, immune responses for the candidates were inferior to those observed in recovered COVID-19 patients as well as those reported for other vaccines. Merck did not disclose the exact response levels but the company is planning to submit the results for publication in a peer-reviewed journal.