Researchers should know by December whether the vaccines in development are safe and effective, according to Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

“I can predict, I believe with some degree of certainty, that by the end of November to the beginning of December, we will know — based on the size of the trial and rate of infections that are ongoing in this country — if we will have a safe and effective vaccine,” Fauci said Wednesday in a virtual keynote address at the University of Alabama at Birmingham’s COVID-19 research symposium, according to

Fauci added that he's "cautiously optimistic that we will have a safe and effective vaccine even though you can never make absolute predictions."

Hospitals in El Paso, Texas, are setting up tents to deal with the increase in COVID-19 patients as the U.S. sees a surge of new cases across the country.

All hospitals in the city, according to ABC News affiliate KVIA, have now started to build tents as of Wednesday night.

"Our hospitals continue to implement our surge plans to expand capacity to help manage the influx of Covid-19 patients to meet the rapidly expanding needs of El Paso," a Hospitals of Providence spokesperson told the station. "Medical tents will help decompress the Emergency Departments."

Texas Gov. Greg Abbott also announced on Wednesday that the El Paso Convention Center is being converted into a health care facility to expand hospital capacity in the area. "The State of Texas is also providing local hospitals with auxiliary medical units, medical staffing, and medical equipment," the Texas Division of Emergency Management said.

There were 845 new cases of COVID-29, which brings the city to at least 13,653 active cases as of Wednesday, according to local officials. There were three new deaths, which brings the death toll in El Paso to 583.

The 7-day rate of positivity in El Paso is 15.57%. There are 908 people currently hospitalized with coronavirus in the city, with 223 patients in ICUs and 111 on ventilators. There are 285 ICU beds in total in El Paso.

With the spike in cases in El Paso, city officials asked residents this week to largely stay at home. "For the next two weeks, we are asking you to please stay home unless for essential activities to reduce the spread of COVID-19 and prevent strain on our hospitals."

In Texas, there have been more than 911,000 diagnosed cases since the pandemic began, with at least 18,162 deaths.

Just days after issuing a countywide curfew, a judge in El Paso County, Texas, ordered a two-week shutdown of nonessential businesses -- a move that was met with pushback from the state attorney general.

Judge Ricardo Samaniego announced Thursday that beginning at midnight, El Paso County will enter a two-week shutdown of nonessential businesses and services, including tattoo parlors, hair salons, gyms and in-person dining. Essential businesses, including polling sites and schools that provide meals, will remain open, he said. 

"Since the inception of this pandemic, El Paso County has never seen this level of infections through our community," Samaniego told reporters at a press briefing Thursday evening. "Our hospitals are at capacity, our medical professionals are overwhelmed and if we don't respond, we will see unprecedented levels of deaths."

The judge said that El Paso had seen a 365.2% increase in COVID-19 hospitalizations since the beginning of the month.

Following the announcement, Texas Attorney General Ken Paxton tweeted that Samaniego "has no authority to shut down businesses" and was violating Gov. Greg Abbott's executive order.

"My office is quickly exploring all legal actions," Paxton said.

El Paso Mayor Dee Margo also questioned the new county order.

"The Judge did not consult me and refuses to return my call, so I am seeking clarification from the Attorney General on the new County order, which does not supersede the Governor's orders," Margo said in a statement.

"We must strike a balance of keeping our neighbors safe while not destroying people's abilities to feed their families," he added.

Several community leaders joined Samaniego in supporting the order.

"In recent days it's apparent that stricter measures are necessary to flatten the curve and, bottom line, save lives," Texas state Rep. Cesar Blanco, a Democrat, said at Thursday's briefing. "The status quo, it's no longer working."

There were 937 hospitalizations due to COVID-19 in El Paso on Thursday, a new record, University Medical Center CEO Jacob Cintron said.

On Sunday, Samaniego ordered a two-week curfew to limit mobility in the community amid rising COVID-19 cases and hospitalizations, and after intensive care units at all area hospitals reached 100% capacity as of Saturday. The curfew has been imposed for 10 p.m. to 5 a.m., and trick-or-treat activities on Halloween are not allowed, Samaniego said.

ABC News' Cherise Rudy, Will Gretsky and Timmy Truong contributed to this report.