Passengers arrive at LAX from Shanghai, China, after a positive case of the coronavirus was announced in the Orange County suburb of Los Angeles, California, January 26, 2020. Ringo Chiu | Reuters

Human trials testing a potential vaccine for the COVID-19 coronavirus are expected to begin in six weeks, U.S. health officials announced Tuesday. "We are on time at least and maybe even a little bit better," Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, an agency within the Department of Health and Human Services, told reporters at a press conference. "Hopefully, no further glitches." The White House reportedly asked Congress on Monday for $1.25 billion in additional funding to bolster its coronavirus response, including money to develop a vaccine and therapeutics to treat the virus. The National Institutes of Health has been working with biotech company Moderna to develop a vaccine using the current strain of the coronavirus.

Hopes to get a vaccine to market are high, but doctors want expectations to be low for how quickly it can happen. Developing, testing and reviewing any potential vaccine is a long, complex and expensive endeavor that could take months or even years, global health experts say. Before researchers can begin human trials, they must have a firm understanding of the pathogen, run safety tests and find enough human volunteers. U.S. health officials are fast-tracking work on a coronavirus vaccine. Fauci said Tuesday that the potential vaccine has so far been put into mice and is "immunogenic," or triggers a response in the immune system, suggesting it could fight the virus. "The gene has been expressed in the platform, in this case, a messenger RNA. The material has been produced, it's been put into mice. It's immunogenic," he said. "It's now getting ready to go through the regulatory issues of getting it to go." Fauci said a vaccine may not solve "problems in the next couple of months but it certainly would be an important tool that we would have." He said it's possible the virus will prove to be seasonal, thus likely to subside in the warmer months like the flu. There are currently no proven therapies for the latest outbreak, which has killed at least 2,704 and sickened more than 80,200 people worldwide since emerging from the Chinese city of Wuhan about two months ago. Local authorities in China have using Gilead Sciences' antiviral drug Remdesivir, which was tested as a possible treatment during the Ebola outbreak, U.S. health officials said last month. Some authorities are also using antiviral drug Kaletra, developed by drugmaker AbbVie, on a "compassionate basis."