Merck discontinuing development of two COVID-19 vaccine candidates 

Merck has halted its development of two potential vaccines for the coronavirus, citing data that showed a lack of immune response.

The two vaccine candidates, which derive from technology used to develop Merck’s Ebola and measles vaccines respectively, generated fewer antibodies than existing vaccines, according to interim trial data.

“We are grateful to our collaborators who worked with us on these vaccine candidates and to the volunteers in the trials,” said Dean Y. Li, president of Merck Research Laboratories. “We are resolute in our commitment to contribute to the global effort to relieve the burden of this pandemic on patients, health care systems and communities.”

Merck said it remains committed to research on COVID-19 and will focus on two treatments it is developing.

Although the news comes as vaccines by Pfizer and Moderna have begun distribution, the rollout of those vaccines has lagged behind initial goals and new, more aggressive, strains of the virus have emerged whose resilience against those vaccines remains unclear.