In another sign of the changing state of the pandemic, an invaluable source of information about the virus over the last three years is shutting down, NPR has learned.

The Johns Hopkins Coronavirus Resource Center plans to cease operations March 10, officials told NPR.

"It's bittersweet," says Lauren Gardner, an engineering professor who launched the project with one of her students on March 3, 2020. "But it's an appropriate time to move on."

When the pandemic erupted, no one knew much of anything about the virus and how to respond. Was it safe to go grocery shopping? How easily could someone get infected on a bus or train? Could runners get sick just by passing another jogger in the park?

"As everyone can remember, there was very little information, particularly at the beginning of the pandemic," says Beth Blauer, an associate vice provost at Johns Hopkins who has helped run the center.

"And when we started to see the cases move out of China and in through Europe and headed toward our shores, we knew that there were going to be a series of public policy decisions that would have to be made," Blauer says.

Those decisions included where to impose dramatic but crucial public health measures. Should mayors close schools? Should governors mandate masks? Should CEOs shut down factories? Should heads of state seal borders?

But there was no good data available to make those decisions. Neither the Centers for Disease Control and Prevention nor the World Health Organization were providing enough useful numbers in real time. So journalists and academic researchers at places like Johns Hopkins jumped in to fill the void.

NPR launched its own tracker in March, 2020, drawing data from Johns Hopkins. It was viewed over 52 million times over the last three years as readers sought to stay updated on COVID metrics. On Feb. 1, NPR ceased updating the page, recognizing that Americans can find the information they need on the CDC's COVID website. This was not the case early in the pandemic.

"I know CDC has the ability to do this and has done it numerous occasions in the past," says Dr. Ali Khan, a former CDC official who is now dean of the College of Public Health at the University of Nebraska Medical Center. "So it was unusual that at the beginning of this COVID pandemic that they did not collect this data and put it out in a timely manor. Extremely unusual and very surprising."

Johns Hopkins "essentially filled the vacuum," Khan says, "That was invaluable to understand what was going on."

After Johns Hopkins launched the project, the website quickly became crucial for deciding everything from where drug companies should test vaccines to where Hollywood should film movies. Even the White House and the British prime minister were relying on Hopkins data.

Gardner recalls many conversations "with people that were just out about doing their job — traveling in Japan, here and there — who would tell me the dashboard was the driving force in decision-making for them ... about quitting their job and then coming home so that they wouldn't get stuck."

The site's maps of the world and individual countries became an iconic way of tracking the virus's inexorable spread.

"I would refresh my computer screen over and over again over the course of the work day looking to see what the latest numbers were," says Dr. Celine Gounder from the Kaiser Family Foundation, who was working as an infectious disease specialist at the Bellevue Hospital in New York when the pandemic began.

"It was really startling to see even over the course of the day how the numbers were evolving. I think my colleagues thought I was a little obsessive," Gounder says. "But it was also watching history unfold in real time on your screen."

The site, which Blauer and Gardner note was created and run largely by women, cost $13 million and eventually drew more than 2.5 billion views, Blauer says.

"It is a staggering amount of traffic," she says. "These are numbers I don't think I'll ever see again in my professional career."

But now that the threat of the pandemic is receding, states are reporting data less frequently and the CDC has ramped up the agency's data reporting, the university decided it was time to shut it down.

"There's definitely a bitter sweetness about the end," Blauer says. "But we are at an inflection point."

Both Blauer and Gardner say they hope the CDC and the public health system will continue to invest in data collection so the nation will be better prepared in the future. But they're prepared to step back in if necessary.

"There will be another pandemic," Gardner says. "And, so we'll have to see."