U.S. Food and Drug Administration panel's endorsement of Moderna's coronavirus vaccine on Thursday had special significance for Sen. Steve Daines, R-Mont. 

Daines, a chemical engineer with experience launching FDA-regulated products, championed an effort in March for $10 billion in federal funding to accelerate the development and manufacturing of the coronavirus vaccines. The funding jumpstarted Operation Warp Speed, the unprecedented effort to develop and distribute vaccines at a record pace. 

"It will be the best $10 billion we've ever spent," Daines told Fox News Thursday shortly after an FDA advisory panel voted to endorse the Moderna vaccine, which got $483 million in federal funds in April. 

FDA PANEL ENDORSES MODERNA’S CORONAVIRUS VACCINE

"If you think about return on investment ... this will have the highest ROI we've ever done in terms of investment from the federal government."

GOP Sen. Steve Daines, center, speaks at a campaign stop in Clancy, Mont. Daines won re-election, beating out Gov. Steve Bullock in one of the most expensive contests of the election season. (Thom Bridge/Independent Record via AP)

In the early days of the pandemic, Daines was concerned the federal government response was too focused on treating the symptoms of the problem and not trying to stop the pandemic. He started talking to federal health leaders on funding vaccine development and manufacturing at the same time so millions of doses would be ready for mass distribution as soon as the product is approved. The dual-track approach shaved about six months off the process, Daines said.

WHO IS STEVE DAINES? 4 THINGS TO KNOW ABOUT THE US SENATOR FROM MONTANA

His $10 billion vaccine proposal was ultimately included in the $2.2 trillion CARES Act relief legislation signed into law in March. And just nine months later, that effort is paying off, Daines said, as the FDA is moving forward with a second vaccine. 

"I kind of see this as an early Christmas present for the American people," Daines told Fox News.

The first vaccine approved came from Pfizer. Unlike Moderna, Pfizer didn't take government funding in the spring for research and development. But the U.S. did sign a $1.95 billion contract with the drugmaker in July to secure 100 million doses for distribution. 

HOW DO THE MODERNA AND PFIZER CORONAVIRUS VACCINES COMPARE?

Daines said these federal government and private sector partnerships will solve the global health crisis. Daines is mindful that of all the actions he's taken as a lawmaker, his $10 billion vaccine effort may be the most consequential. 

"I'll look back at this as one of the most rewarding experiences I've had in my time in Congress," Daines said.