Merck stops two Covid-19 vaccine candidates

Pharmaceutical giant Merck said on Monday it was halting development of its two candidate Covid-19 vaccine candidates after initial clinical trial data showed a “lower” immune response.

Merck said in a statement on its website that the decision to withdraw the two vaccine candidates followed its review of the results of Phase 1 clinical studies. The studies showed that both candidates were generally well tolerated, but that the immune responses were lower than those observed following natural infection with Covid-19 and those reported for other Covid-19 vaccines.

Merck was late in joining the race to develop a vaccine to protect against the virus, which has so far killed more than 2 million people worldwide and infected nearly 100 million.

U.S. regulators cleared Covid-19 vaccines from Moderna and its partners Pfizer and BioNTech in December, and tens of millions of doses of both have so far been administered around the world as governments around the world rush to vaccinate as many people as possible to lift damaging locks.

Rivals Johnson & Johnson, AstraZeneca Plc and others are also working to develop safe and effective vaccines to protect against the virus.

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Merck still plans to submit the results of Phase 1 studies for the two discarded vaccine candidates for publication in a peer-reviewed journal, according to its release.

The company will now focus on two investigational drugs Covid-19 and further research on Covid-19, the statement added.

Reuters contributed to this report.