Merck cancels the development of two possible COVID-19 vaccines due to poor initial results

Merck will stop developing two possible COVID-19 vaccines after poor results in initial studies.

The pharmaceutical company said on Monday that it will instead focus on studying two possible treatments for the virus that have not yet been approved by regulators. The company said its possible vaccines were well tolerated by patients, but generated a lower immune system response compared to other vaccines.

Merck was developing one of the possible vaccines with the Institut Pasteur in France based on an existing measles vaccine. The French institute said it will continue to work on two other vaccine projects using different methods.

Merck entered the race to fight COVID-19 later than other major drug manufacturers.

He said last fall that he had begun early-stage research into volunteers on possible vaccines that require just one dose. The vaccines developed by Pfizer and Moderna were already at an advanced stage of research at this time.

The Food and Drug Administration allowed emergency use of the Pfizer and Moderna vaccines late last year. Each requires two doses.

Five possible vaccines have reached the advanced stage of testing in the United States, the final phase before a drug manufacturer seeks regulatory approval. The results of a single-dose candidate developed by Johnson & Johnson are expected soon.

Since vaccines began in December, nearly 22 million doses have been delivered to people across the country, according to the Centers for Disease Control and Prevention. Almost 6% of the population has received at least one dose.

A total of 3.2 million people, or 1% of the population, have received the two doses needed for these vaccines.