Federal officials are shifting an additional $81 million dollars for anti-Zika efforts, as Congress remains gridlocked over providing extra emergency funds to fight the virus.

Secretary of Health and Human Services Sylvia Burwell is using her transfer authority to reallocate funds from other areas, allowing researchers to move ahead with testing the most promising Zika vaccine, Dr. Anthony Fauci, director of the National Institutes of Health's National Institute of Allergy and Infectious Diseases, told reporters Thursday.

The additional funds will allow Fauci to conduct the first clinical trial of a potential vaccine this fall. But they're not enough to ensure he'll be able to start preparing testing sites for a second trial phase of the vaccine or start trials of alternative Zika vaccines. Without additional funding from Congress this fall, researchers will hit road blocks by year's end, Fauci said.

"I'm actually good now until November or December, [but then] we're going to start getting into trouble," Fauci said.

Congress is fighting over a bill delegating emergency funds for prevention and research efforts to combat the Zika virus, which has been found in 1,825 people in the U.S. including more than 400 pregnant women. While the virus causes only mild symptoms in patients, it can cause severe birth defects for the fetuses of pregnant women infected with it.

Lawmakers left town last month without reaching agreement on a $1.1 billion bill the Republican-led House passed. Democrats blocked the measure in the Senate, objecting to provisions that banned Planned Parenthood from getting any of the funds.

To conduct what NIH officials describe as a "comprehensive approach" to developing a Zika vaccine, the agency has requested $277 million in additional dollars.

To meet some of the need, Burwell is using her authority to transfer money from other areas, although that authority is limited to 1 percent of her agency's total budget. Of the $81 million she's tranferring, $34 million is being shuffled within NIH and $47 million is being reallocated in the Biomedical Advanced Research and Development Authority.

But Fauci said NIH needs about $200 million more to test at least three more potential vaccines in multiple clinical trials.

"Otherwise, the second, third and fourth candidates will not only get slowed down — we wouldn't be able to start them at all," Fauci said at a Zika briefing at the National Press Club.

And he stressed that even though agencies can shuffle around some money, it sets a poor precedent for handling research dollars, stripping funds away from other areas of research like cancer and diabetes.

"Just because you can do it...[Burwell] made a courageous decision to something she really did not want to do...it isn't okay," Fauci said. "It's damaging to the biomedical research enterprise."