How Merck's Vaccine Lost the Covid Race

Merck, which was founded in 1891, has been in the vaccine business for more than 100 years, having developed some of the world’s most well-known vaccines, including those for mumps, hepatitis A and chickenpox. In 2019, it was the first company to win approval from the Food and Drug Administration for an Ebola vaccine.

When the coronavirus began spreading around the world, however, Merck was slow to announce plans for a vaccine. By the time it provided details about two vaccine candidates in late May, most of its major competitors had already announced deals, and Pfizer and Moderna had already begun early clinical trials.

But Merck didn’t have to be first to win. Executives decided to pursue two projects that they felt had advantages over competitors. One vaccine, developed in partnership with the International AIDS Vaccine Initiative, would rely on the same technology, based on a harmless livestock virus, that had yielded their successful Ebola vaccine. The other, acquired through a purchase of Themis Bioscience, was based on an existing measles vaccine.

Both of the experimental Covid vaccines, the company said, would be tested using a single dose, and Merck was also exploring whether the one using the livestock virus could be given orally — two big edges over potential competitors, especially in the developing world.

In July, Merck’s chief executive, Kenneth C. Frazier, warned against moving too quickly. “I think when people tell the public that there’s going to be a vaccine by the end of 2020, for example, I think they do a grave disservice to the public,” Mr. Frazier said in an interview with a Harvard Business School professor. Mr. Frazier recently announced that he would retire as chief executive later this year, a decision that had been long planned.

In an interview in August, Dr. Nicholas Kartsonis, Merck’s senior vice president of clinical research for vaccines and infectious diseases, said the company’s position as leading vaccine maker gave it the luxury of time. “We are a much larger company. We are not as beholden to having to be first,” he said.