Merck, the pharmaceutical giant with around 10,000 employees in Montgomery County, has discontinued work on its COVID-19 vaccine candidates and refocused its efforts on the development of its two therapeutic candidates, writes John George for the Philadelphia Business Journal.

According to Merck officials, the decision was made after a review of phase-I clinical studies of the company’s vaccine candidates. The data showed that the vaccine was well tolerated but the immune responses it produced were inferior to those recorded in people who have already overcome natural infection and those reported by other companies for their vaccines.

“We are grateful to our collaborators who worked with us on these vaccine candidates and to the volunteers in the trials,” said Dr. 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.”

The company is now advancing its clinical programs and scaling up manufacturing on its two medicines that are being developed to treat COVID-19 patients.

Merck stock dropped less than one percent following the announcement.

Read more about Merck at the Philadelphia Business Journal by clicking here.