The N.I.H. says it is not giving up in patent fight with Moderna.

The National Institutes of Health is prepared to aggressively defend its assertion that its scientists helped invent a crucial component of the Moderna coronavirus vaccine — including taking legal action if government lawyers deem it necessary, the agency’s director, Dr. Francis Collins, said Wednesday.

Moderna’s vaccine, which appears to provide the world’s best defense against Covid-19, grew out of four years of collaboration with research scientists at the N.I.H.’s Vaccine Research Center. The New York Times reported on Tuesday that the company has blocked three N.I.H. researchers from being named on a key patent application.

Much more than scientific recognition is at stake. If federal researchers were named as co-inventors in the patent, the government would have a nearly unfettered right to license the Moderna vaccine to other manufacturers, which could expand access to it in poorer nations and bring the government millions in revenue.

Dr. Collins declined to be interviewed. But speaking to Reuters in advance of a virtual health conference hosted by the news service, he made clear that the N.I.H., the government’s biomedical research agency, was not backing down.

“I think Moderna has made a serious mistake here in not providing the kind of co-inventorship credit to people who played a major role in the development of the vaccine that they’re now making a fair amount of money off of,” he told Reuters. He added: “But we are not done. Clearly this is something that legal authorities are going to have to figure out.”

A spokeswoman for Dr. Collins, Renate Myles, stopped short of saying the dispute was headed to court.

“Dr. Collins simply stated that N.I.H. is not giving up on our claim that N.I.H. is a co-inventor on the mRNA technology use in the Moderna COVID-19 vaccine, but defers to legal authorities on how this might be resolved,” she said. By legal authorities, she said, Dr. Collins meant government lawyers.

The three government researchers that N.I.H. has been trying to get named alongside Moderna employees as co-inventors of the genetic sequence at the core of how the vaccine triggers an immune response.

As the virus began to spread in January 2020, scientists at N.I.H. and Moderna worked in parallel over a single weekend to zero in on the gene for the virus’s spike protein. Both teams independently identified the same gene.

Moderna has so far rebuffed the government’s efforts. In a July filing with the United States Patent and Trademark Office, Moderna said it had “reached the good-faith determination that these individuals did not co-invent” the component.

Moderna’s chief executive, Stéphane Bancel, said Wednesday the company was in confidential discussions with the N.I.H. and would communicate publicly if a resolution to the dispute is reached.

“What we just need to work out with the N.I.H. is who are the inventors. And there are very clear rules set out by the law about inventorship, and they are very important to protect the patent,” Mr. Bancel said at a virtual conference put on by Wired magazine.

Moderna has received $1.4 billion from the federal government to develop its vaccine and another $8.1 billion to provide the country with half a billion doses. It is also earning billions in profits from supply deals.

Biden administration officials have said they lack the legal authority to require the company to share its vaccine recipe and technical know-how with manufacturers who could produce it at a lower cost for poorer countries.

After Dr. Collins’s comments were reported, a Moderna spokeswoman, reiterated that the company has concluded that only Moderna scientists came up with the sequence that powers the vaccine.