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

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

The pharmacist said on Monday that he would instead focus on studying two possible treatments for the virus that have not yet been approved by regulators. The company said its potential vaccines were well tolerated by patients, but caused a lower immune response compared to other vaccines.

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

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

He said in the fall of last year that he had begun early research on volunteers about possible vaccines that required a single dose. The vaccines developed by Pfizer and Moderna were already at an advanced stage of research at the time.

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

Five potential vaccines have reached the advanced stage of testing in the United States, the final stage before a drugmaker 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 given to people across the country, according to the Centers for Disease Control and Prevention. Almost 6% of the population received at least one dose.

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