Merck is terminating the Covid vaccine program, citing weaker immune responses

Merck, a pharmaceutical company, announced on Monday that it will complete the development of two Covid-19 vaccines and focus pandemic research on treatments, with initial efficacy data expected by the end of March for an experimental oral antiviral drug.

Merck said it will record a fourth-quarter waiver fee for the V591 vaccine candidate in the fourth quarter, which it acquired with the Austrian vaccine manufacturer Themis Bioscience and the VAV90 vaccine manufacturer, developed with the nonprofit research organization IAVI.

In early studies, both vaccines generated immune responses that were worse than those seen in people who recovered from Covid-19, as well as those reported with other Covid-19 vaccines, the company said.

Merck joined the race to develop a vaccine against the coronavirus, which has so far killed more than 2 million people and is growing steadily in many parts of the world, including the United States.

U.S. regulators approved Covid-19 vaccines from Moderna and its partners, Pfizer and BioNTech, in December, and tens of millions of doses of both have been administered worldwide to date. Rivals Johnson & Johnson, AstraZeneca and others are competing to develop safe and effective vaccines to protect against the virus.

Merck says Covid-19 will focus its research and manufacturing efforts on two investigational drugs: MK-7110 and MK-4482, which it now calls molnupiravir.

Molnupiravir, developed in collaboration with Ridgeback Bio, is an oral antiviral agent that is being tested in both hospital and outpatient settings. Merck said the phase 2/3 trial of the drug should be completed in May, but initial efficacy results are due in the first quarter and will be clinically significant.

Merck said the results of a phase 3 study of MK-7110, an immunomodulator, are expected in the first quarter to treat patients hospitalized with severe Covid-19. In December, the company announced the delivery of the MK-7110 to the U.S. government for about $ 356 million.