US laboratory Merck says halting work on Covid vaccines

NEW YORK: US pharmaceutical giant Merck announced Monday it was halting work on two potential Covid-19 vaccines, but would continue to develop therapeutics to treat the deadly virus.

The two vaccine candidates "were generally well tolerated, but the immune responses were inferior to those seen following natural infection" and compared with other Covid-19 vaccines, Merck said in a press release.

One of the candidates had been pursued in tandem with France's Pasteur Institute, which said it continues to research "two other vaccine candidates which use different methodologies."

The announcement is a setback for the global effort to contain Covid-19, which has accounted for nearly 100 million cases worldwide and more than 2.1 million fatalities.

There are currently seven vaccines circulating around the world.

The vaccines developed by Pfizer-BioNTech (US-German) and Moderna (US) are dominant in North America, Europe, Israel and the Gulf.

Britain's AstraZeneca-Oxford is used in much of the UK and India, with the latter also using a vaccine by Bharat Biotech.

Russia's Sputnik V vaccine and two vaccines from China, Sinopharm and Sinovac, are being used across a dozen countries, but they have yet to be fully approved.

Merck said it plans to continue work on two treatments for the virus.

One of these therapeutics, MK-7110, "modulates the inflammatory response" to the virus; interim clinical results showed a more than 50 percent reduction in the risk of death or respiratory failure in patients with severe Covid-19, Merck said.

Merck expects initial clinical data in the first quarter of 2021 on the other therapeutic, an "oral novel investigational antiviral agent," the company said.

"We are grateful to our collaborators who worked with us on these vaccine candidates and to the volunteers in the trials," said Dean Li, president of Merck 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."