In this photo taken Sunday, Nov. 4, 2018 and made available Tuesday, Dec. 4, 2018, a caretaker already cured of Ebola is seen carrying a four day old baby suspected of having Ebola into a Medecins Sans Frontieres (MSF) supported Ebola treatment centre in Butembo, Congo. Congo's deadly Ebola outbreak is now the second largest in history, behind the devastating West Africa outbreak that killed thousands a few years ago, according to the World Health Organization. (John Wessels/Medecins Sans Frontieres via AP)

FILE - In this Nov. 29, 2018 file photo, former mayor of New York City, Michael Bloomberg, speaks to the media in Jackson, Miss. Bloomberg’s philanthropy has announced a $50 million donation to help fight the nation’s opioid epidemic. Bloomberg Philanthropies says over the next three years it’ll help up to 10 states address the causes of opioid addiction and strengthen prevention and treatment programs. (AP Photo/Rogelio V. Solis)

First lady Melania Trump attends a ceremony to pardon the National Thanksgiving Turkey in the Rose Garden of the White House in Washington, Tuesday, Nov. 20, 2018. (AP Photo/Andrew Harnik)

Eugene Bell Foundation Chairman Stephen Linton speaks during a news conference in Seoul, South Korea, Friday, Nov. 16, 2018. The U.S.-based nonprofit group called for South Korea to take stronger steps to fight a tuberculosis crisis in North Korea it says has worsened under strengthened U.S.-led sanctions over its nuclear weapons and missile program. (AP Photo/Lee Jin-man)

House Minority Leader Nancy Pelosi, D-Calif., speaks in during a news conference on Capitol Hill in Washington, Wednesday, Nov. 7, 2018. Pelosi says she's confident she will win enough support to be elected speaker of the House next year and that she is the best person for the job. (AP Photo/J. Scott Applewhite)

President Donald Trump holds a pen up after signing bipartisan legislation to confront the opioid crisis in the East Room of the White House, Wednesday, Oct. 24, 2018, in Washington. (AP Photo/Evan Vucci)

FILE - In this Sunday, Sept 9, 2018 file photo, a health worker sprays disinfectant on his colleague after working at an Ebola treatment centre in Beni, Eastern Congo. The World Health Organization is announcing on Wednesday, Oct. 17 whether Congo's latest outbreak of the deadly Ebola virus should be declared a global health emergency. (AP Photo/Al-hadji Kudra Maliro, file)

FILE - In this Feb. 26, 2015 photo taken through the eyepiece of a microscope, human cells infected with the flu virus glow green under light from a fluorescence microscope at a laboratory in Seattle. The U.S. government estimates that 80,000 Americans died of flu and flu complications in the winter of 2017-2018 - the highest flu-related death toll in at least four decades. (AP Photo/Ted S. Warren)

FILE - In this Sept. 6, 2018, file photo, House Minority Leader Nancy Pelosi, D-Calif., speaks during her weekly news conference on Capitol Hill in Washington. Consumer and health care groups say they’re trying to block a move by the pharmaceutical industry to commandeer must-pass opioids epidemic legislation as a vehicle for rolling back drugmaker discounts to Medicare beneficiaries with high prescription costs. Republican leaders were saying little about behind-the-scenes discussions on Sept. 21,, but a spokesman for Pelosi calls it a “a multi-billion dollar handout to Big Pharma.” (AP Photo/Jose Luis Magana, File)