An infectious disease expert is warning that there may be grave consequences for states that begin easing pandemic lockdown restrictions too early.

Michael Osterholm, the director of the Center for Infectious Disease Research and Policy at the University of Minnesota, said that states who insist on opening "will pay a big price later on," and likened easing restrictions to "putting gasoline on fire."

Mr Osterholm's comments were made during an interview with Jake Tapper on CNN.

"I think right now, this is one of the things we've learned, if we're going to learn to live with this, then you just don't walk in the face of it and spit in its eye, because it will hit you," he said. "And that's a really important issue right now. When we have transmission increasing, when our hospitals are not able to take care of it and we don't have enough testing to even know what's going on, then that's not the time to loosen up."

States like Georgia, Florida and Nevada have considered or have begun lifting stay-at-home orders, allowing people back into the public to shop and work, and - potentially - catch and spread the virus.

Mr Osterholm said that the American public - and its officials - have to start considering how they will deal with a long-lingering virus.

"We have to have, as a population, the same discussions about not just how we're going to die with this virus, but how we're going to live with it for the next 16 or 18 months," Mr Osterholm said. "This is not a battle, this is a war."

Mr Osterholm pointed to a recent study highlighted by New York Governor Andrew Cuomo during a press briefing that suggested 13.9 per cent of New Yorkers had coronavirus antibodies.

The infectious disease expert said that the low number was indicative of how much further the US had to go before the population reached any kind of herd immunity.

"Think of all [New Yorkers] have been through, and yet how far we have to go, because this virus will keep marching until we hit 60, 70 per cent positive for antibody, which means you either got it through disease or you get it through a vaccine, and a vaccine isn't coming soon," he said.

Researchers are still uncovering new information about the origin of the US coronavirus outbreak.

As more information becomes available, experts now believe a woman in Los Angeles was the first to die in the US from the virus in early February.

According to experts, she did not become infected as a result of travel, but was infected through her community, suggesting the virus was already circulating in the US prior to her early February death.

Mr Osterholm said that while the virus has been spreading for longer than initially thought, the US still needs to be ready for a much longer fight.