Ethan Lindenberger, a high school senior in Ohio, gained national attention after he went on Reddit in December to ask how to get vaccinated now that he was 18 and free to act without the consent of his anti-vaccination mother. (The Centers for Disease Control and Prevention has advice.)

On Tuesday, Lindenberger testified before the Senate health committee, focusing on the need to fight misinformation and conspiracy theories about vaccinations — especially on Facebook — with "credible" information and better social media curation.

"I feel like if my mom didn't interact with that information ... it could've potentially changed everything," Lindenberger said. "My entire family could've been vaccinated." He said he decided to get himself immunized after slowly realizing the benefits vastly outweighed any risks, and that "my school viewed me as a health threat."

Lindenberger would argue with his mother, citing the CDC and other sources, he told the Senate, but she would counter with baseless claims she saw on Facebook. "She didn't trust any sources," he told The Washington Post. "She thought vaccines were a conspiracy by the government to kill children."

Lindenberger's mother, Jill Wheeler, told The Associated Press she was proud of how her son comported himself in the hearing, though "I didn't agree with anything he said" and wondered why "they've made him the poster child for the pharmaceutical industry."

Facebook isn't just a conduit for bad information on vaccines, it also hosts self-reinforcing anti-vaccination groups and serves "targeted advertisements and anti-vaccination materials aimed toward women in regions with high numbers of measles reports," the Post reports. Anti-vaccination "hot spots" have fueled six current outbreaks of measles in 11 states, though the highly contagious disease was eliminated in the U.S. in 2000.

A major study published Monday confirmed that the measles, mumps, rubella (MMR) vaccine is safe and does not cause autism. Learn more in the video below. Peter Weber

Congressional leaders met with President Trump at the White House to discuss the mess in Syria on Wednesday, and it didn't go well. House Speaker Nancy Pelosi (D-Calif.) said Trump had a "meltdown" and she was praying for his health. Using his patented I'm-rubber-you're-glue strategy, Trump responded that Pelosi had an "unhinged meltdown" — posting a photo that didn't appear to have the intended effect — and tweeted "Pray for her."

The 20-minute meeting started with Trump saying he didn't want to be there, The New York Times reports, citing several Democratic officials and noting that "the White House did not dispute their accounts." Trump brought up a bizarre letter he sent to Turkey's Recep Tayyip Erdogan, claiming his "nasty" missive shows he didn't green-light Turkey's invasion of Syria. Pelosi noted that the House had just overwhelmingly condemned Trump's decision to withdraw the handful of U.S. troops that had been keeping Turkey at bay.

Senate Minority Leader Chuck Schumer (D-N.Y.) started to read Trump a quote from his former defense secretary, James Mattis, at which point Trump called Mattis "the world's most overrated general" because "he wasn't tough enough" and "I captured ISIS" faster than he'd said was possible. Pelosi said Russia has long sought a "foothold in the Middle East" and he had just given Russian President Vladimir Putin such an opening, adding: "All roads with you lead to Putin." That's when the already-tense meeting "reached a fever pitch," the Times reports.

The Associated Press recounts the next few exchanges:

Trump: "I hate ISIS more than you do."

Pelosi: "You don't know that."

Schumer: "Is your plan to rely on the Syrians and the Turks?"

Trump: "Our plan is to keep the American people safe."

Pelosi: "That's not a plan. That's a goal."

After Trump called Pelosi either a "third-rate" or "third-grade" politician, House Majority Whip Steny Hoyer (D-Md.) said "this is not useful," and the Democrats walked out. Trump said: "Goodbye, we'll see you at the polls." White House Press Secretary Stephanie Grisham said of the meeting: "The president was measured, factual, and decisive, while Speaker Pelosi's decision to walk out was baffling, but not surprising." Peter Weber

In the early 20th century, hunting almost entirely wiped out the southwest Atlantic humpback whale, but scientists say it appears that the population has almost fully recovered.

There are seven different humpback populations in the southern hemisphere, and it's believed that before they were almost hunted to extinction, there were 27,000 southwest Atlantic humpback whales in the ocean, BBC News reports. The southwest Atlantic humpback whales spend their winters off the coast of Brazil and travel to sub-Antarctic and Antarctic waters during the summer to feed off krill.

Humpback whales became protected in the 1960s, and Dr. Alex Zerbini of the National Marine Fisheries Service told BBC News the populations weren't measured until the 1980s. Scientists have since been documenting the southwest Atlantic humpback whales, surveying them by ship and plane, and at the start of the 2000s, "we realized just how well they were recovering," Zerbini said. It's estimated there are now nearly 25,000 of these whales in the world, which is a "positive story," Zerbini said. Catherine Garcia

The Marine Corps on Wednesday confirmed the suspicions of three historians who believed that one of the six men in the famed photo of a U.S. flag being raised over Iwo Jima had been misidentified.

One of the most recognizable photos from World War II, the picture earned Associated Press photographer Joe Rosenthal a Pulitzer Prize. It was snapped during the second flag raising on Mount Suribachi — the first flag was deemed too small, and a larger one was put up a few hours later.

Historians Stephen Foley, Dustin Spence, and Brent Westemeyer studied film footage and pictures taken by soldiers on Iwo Jima, and decided that the person identified in the famous photo as Pfc. Rene Gagnon was actually Cpl. Harold "Pie" Keller, a Purple Heart recipient from Iowa. The Marine Corps told NBC News on Wednesday that investigators from the FBI's Digital Evidence Laboratory have concluded that the historians were correct.

The Marine Corps said in a statement Gagnon was responsible for "returning the first flag for safe keeping," and regardless of who appears in the photograph, "each and every Marine who set foot on Iwo Jima, or supported the effort from the sea and air around the island is, and always will be, a part of our Corps' cherished history." Keller's daughter Kay Maurer told NBC News the family was shocked to learn he was in the picture, as her father "never spoke about any of this when we were growing up." Both Keller and Gagnon died in 1979. Catherine Garcia

Energy Secretary Rick Perry led the U.S. delegation to Ukrainian President Volodymyr Zelensky's inauguration in May. In a subsequent May 23 meeting in the White House, President Trump said he wouldn't agree to meet Zelensky until the Ukrainians "straightened up their act," Perry told The Wall Street Journal on Wednesday, adding that he later understood Trump to be referring to concerns about his 2016 presidential campaign. In order to resolve those concerns, Perry said, Trump told him to "visit with Rudy," meaning Trump lawyer Rudy Giuliani.

Perry says he agreed to call Giuliani in the hopes it would ease the way for Trump to meet with Zelensky. "And as I recall the conversation, he said, 'Look, the president is really concerned that there are people in Ukraine that tried to beat him during this presidential election,'" Perry told the Journal. "Rudy didn't say they gotta do X, Y, and Z," he added. "He just said, 'You want to know why he ain't comfortable about letting this guy come in? Here's the reason.'"

Those reasons, Perry recalled, involved three conspiracy theories: That Ukraine was responsible for former British spy Christopher Steele's dossier on Trump; that Ukraine had Hillary Clinton's email server; and that Ukrainian's "dreamed up" evidence that led to Paul Manafort's conviction and imprisonment.

Trump's former homeland security adviser, Thomas Bossert, said last month he was "deeply frustrated" that Giuliani had poisoned Trump's mind with those "completely debunked" conspiracy theories. Perry had a more detached response. "I don't know whether that was crap or what," he said, "but I'm just saying there were three things that he said. That's the reason the president doesn't trust these guys."

Trump finally called Zelensky on July 25, and their conversation — specifically Trump's request that Zelensky investigate Joe Biden and his son — led to a whistleblower complaint and a House impeachment inquiry. In that inquiry, several diplomats have expressed concerns about Giuliani's shadow diplomacy in Ukraine on behalf of Trump and possibly other clients. Federal prosecutors in New York are also reportedly investigating Giuliani's Ukraine business dealings. Read more at The Wall Street Journal. Peter Weber

More than 30,000 Chicago Public Schools teachers and support staff will go on strike Thursday, after the unions were unable to reach a deal with the district.

"We have not achieved what we need to bring justice and high quality schools to the children and teachers of Chicago," Chicago Teachers Union President Jesse Sharkey said Wednesday night. "We need to have the tools we need to do the job at our schools. We need pay and benefits that will give us dignity and respect. We are on strike until we can do better." In response to the strike, Chicago Mayor Lori Lightfoot said that at "every turn, we bent over backwards to meet the unions' needs."

About 300,000 students attend Chicago's public schools; Lightfoot canceled classes for Thursday, but said administrators will be at all schools in case kids need a safe place to go. Negotiations will start again on Thursday. Chicago has the United States' third-largest school district. Catherine Garcia

Well, that backfired.

After an explosive meeting on Wednesday afternoon between President Trump and Democratic leaders — which included Trump insulting House Speaker Nancy Pelosi (D-Calif.) and the Democrats walking out — the president decided to unwind by continuing the fight on Twitter. He posted several photos from the meeting, including one showing Pelosi standing and pointing at a sitting Trump. "Nervous Nancy's unhinged meltdown!" he captioned the picture.

Trump may have thought this was a sick burn, but most of the comments under the picture were not favorable. Some people told him he was the one who appeared nervous, and others pointed out that several of his advisers looked like they would rather be anywhere else in the universe than in that room. As for Pelosi, she's a big fan of the photo that literally shows her standing up to the president — it's now her Twitter banner. Catherine Garcia