Researchers at the University of Oxford are looking for 64 healthy people between the ages of 18 and 30 who have recovered from COVID-19. In a new, first-of-its kind study, the volunteers will be reinfected with the original strain of the coronavirus first identified in Wuhan, China, under controlled, quarantined conditions for 17 days, the university said Monday.

The main goal of the challenge trial is to discover what levels and types of immunity are needed to prevent reinfection, which could aid vaccine developers going forward. So far, natural infections and vaccines appear to provide strong protection against reinfection for the most part, but it's unclear how long that will last. The study may also reveal how much virus it takes to reinfect a recovered patient.

While Oxford is excited about the study's potential, challenge trials have their critics, who argue that deliberately infecting someone is unethical, regardless of the circumstances. Read more at Bloomberg. Tim O'Donnell

House Minority Leader Kevin McCarthy (R-Calif.) on Tuesday slammed the House's Jan. 6 commission deal, and in the process appeared to throw Rep. John Katko (R-N.Y.), the Republican he reportedly tasked with negotiating the legislation, "under the bus."

In a statement, McCarthy specifically complained that the commission was too narrow. He and other Republicans want it to examine what he calls "interrelated forms of political violence" in the U.S., including the Black Lives Matter protests from last summer, and he accused the bipartisan deal of focusing mostly on the Capitol riot.

While McCarthy's opposition to the apparently not-so-bipartisan-deal isn't surprising, some analysts are questioning why he had Katko negotiate in the first place. Perhaps recognizing the position Katko was in, McCarthy did appear to take a softer tone after a GOP conference meeting later on Tuesday, telling Politico's Melanie Zanona that his colleague "worked hard to improve the bill, but it's just not there yet." Tim O'Donnell

Former New York City Mayor Rudy Giuliani's son is eyeing an Andrew vs. Andrew gubernatorial battle in 2022.

Andrew Giuliani on Tuesday announced he's running for governor of New York in the state's 2022 Republican primary, launching a campaign website as he seeks to oust New York Gov. Andrew Cuomo (D), NBC News reports. In an interview with The New York Post, Giuliani described himself as a "politician out of the womb."

"Giuliani vs. Cuomo," he also said. "Holy smokes. It's Muhammad Ali vs. Joe Frazier. We can sell tickets at Madison Square Garden. It would be one of the epic showdowns in the state's history."

The announcement comes less than a month after federal investigators searched the Manhattan home and office of Rudy Giuliani, former President Donald Trump's personal lawyer, amid an investigation into his Ukraine business dealings.

Andrew Giuliani served in the White House under Trump, but he has never held elected office. He argued to the Post that "my four years in the White House has prepared me for this moment."

Meanwhile, though, Rep. Lee Zeldin (R-N.Y.) announced a gubernatorial campaign against Cuomo last month, which Politico notes "could complicate" Giuliani's path to the Republican nomination. According to the Post, Giuliani has spoken with Trump about his campaign, but the former president "isn't taking sides because he is also fond of Zeldin." Brendan Morrow

A group of Japanese doctors is backing demands to cancel the Olympics.

The Tokyo Medical Practitioners Association in a letter to Japanese Prime Minister Yoshihide Suga called for the upcoming Tokyo Olympics to be called off due to the country's COVID-19 surge, The Washington Post and Reuters report.

"We strongly request that the authorities convince the [International Olympic Committee] that holding the Olympics is difficult and obtain its decision to cancel the Games," the group said.

These doctors are hardly alone in this request. A recent poll showed that a majority of people in Japan are opposed to holding the Tokyo Olympics in July, with only 14 percent wanting them to go forward this summer, and protesters in Tokyo have been demonstrating against plans for the games. COVID-19 cases have been up in Japan, and just about 3.5 percent of its population has been vaccinated, according to Reuters.

The Tokyo doctors warn in their letter that "the medical institutions dealing with COVID-19 have their hands full and have almost no spare capacity" and that if holding the Olympics contributes to more deaths, "Japan will bear the maximum responsibility," per Reuters. This was at least the second doctor's group to call for the Olympics to be canceled, the Post notes.

Suga, though, has said the Olympics, which won't have any foreign spectators, will be able to be carried out in a "safe and secure" fashion, and the International Olympic Committee says it's "moving fully ahead." After being delayed a year due to COVID-19, the games are scheduled to begin on July 23. Brendan Morrow

Stephen Miller, former President Donald Trump's far-right immigration czar, has tweeted 10 messages in favor of New York City mayoral candidate Andrew Yang over the past week, and "Yang's campaign is not happy about it," Politico's Playbook reports Tuesday. Yang's campaign has been inundated with questions about why the man behind Trump's Muslim ban and child-separation policy is talking up their Democratic candidate, and the campaign would like to know the answer to that, too.

"It's hurting us" and "making people question why people like Andrew Yang," one Yang campaign aide told Politico. "Stephen Miller doesn't endorse normal Democrats," he is likely scaring off "normy Dems," and he "must know" he's hurting Yang's candidacy.

Yang led in the Democratic primary polls until he was recently overtaken by Eric Adams, and "there are suspicions in New York political circles that Miller is sabotaging Yang to help Adams, who is considered to be the more conservative of the two," Politico reports. Miller told Politico he "would never play that game," adding, "As much as I disagree on issues with Yang, I've admired that he's taken on positions antithetical to the progressive left in a very progressive primary."

Miller said his kind tweets about Yang may even help the 2020 Democratic presidential candidate in his mayoral race. "He hasn't made any real significant attempt to distance himself from Republican praise," Miller argued, "which suggests to me that he, as an individual, understands that there are a lot of independent voters in the primary." Yang said he "certainly would never ask for or want" the support of Republican officials. Peter Weber

Stephen Colbert agreed with his fellow late-night hosts that the CDC's reliance on the honor system to keep unvaccinated Americans in masks is unlikely to be effective. "Okay, the only thing Americans need to stay safe is to be honest with themselves," he said on Monday's Late Show. "We are doomed. Do you know what the serving size of Oreos is? It's not 'sleeve.'"

Meanwhile, it was another "bad day for Florida congressman Matt Gaetz," Colbert said. "Gaetz is being investigated by the feds for alleged sex trafficking and having sex with a minor, and it looks like his so-called wingman is ready to sing, man." Today, Joel Greenberg "officially pleaded guilty and agreed to cooperate with prosecutors."

"It's not just Greenberg's guilty plea that spells bad news for Gaetz," Colbert said. "We just learned that, reportedly, at a 2019 fundraiser, Gaetz snorted cocaine and had sex with an escort who was paid with campaign money. So don't worry, donors, you didn't flush your money down the drain — Gaetz placed it on the dresser." After a few more jokes, Colbert moved on. "Okay, enough GaetzGaete," he said. "Let's turn to a completely different story, GatesGaete!" His recap of Bill Gates' problems included a lot of Microsoft jokes.

Greenberg's plea deal "doesn't seem like great news for Gaetz," Late Night's Seth Meyes agreed. "I'd say Matt Gaetz should lay low for a while, but no matter how low he lays, you can still see the top of his head." More Gaetz revelations are probably coming but "we already knew about the drug-fueled sex parties and the trip to the Bahamas with his other buddy, a Florida hand surgeon and marijuana entrepreneur — which is one of the characters in Florida Clue, along with a vaping gator in a Margaritaville tank-top," he joked.

Grown men shouldn't have a "wingman," Meyers said, "but on the topic of wingmen, one could argue Rudy Giuliani served the role for Trump." Former President Donald Trump has reportedly "blown off Rudy's pleas for help," even though he "is deeply entangled in Rudy's mess, not to mention he's got his own legal problems, including multiple criminal investigations of his own." In fact, Meyers said. "I don't want to make generalizations, but there are more criminals or alleged criminals in Trump's inner circle than there are in a motorcycle gang or a Hollywood PTA meeting." Watch below. Peter Weber

"Last week, the CDC officially announced that aside from a few exceptions, people who have gotten the COVID vaccine no longer need to wear masks to stay safe," Trevor Noah said on Monday's Daily Show. "But now, some people are telling the CDC to slow their roll," worried it's too soon to unmask, especially with no way to tell who is vaccinated.

The honor system is not a workable solution, Noah said. "I mean, have you ever seen the 10 Items or Less line?" In reality, "lots of unvaccinated people won't be wearing masks," while, "a lot of vaccinated people who don't need to wear a mask anymore are gonna keep doing it anyway," he said. "In fact, it kind of warms my heart a little bit to think that somewhere, a liberal who's wearing a mask even though he's vaccinated will run into a conservative wearing a mask to protect himself from vaccines, and the two of them will look at each other and think, 'Yeah, this guy gets it.'"

"For the new guidelines to work, the CDC is asking Americans to be honest about their vaccination status," Jimmy Fallon said at The Tonight Show. "Really? People can't even tell the truth on their Tinder profiles." In a boring new New York Times exposé, President Biden's advisers say he's "obsessed with details, asks many questions, and displays unexpected warmth," Fallon said. "The report also says that Biden's drink of choice is Orange Gatorade. Is it? Or is it just water with Metamucil?" He also had fun with Biden's unearthed Venmo history.

Biden apparently used his since-deleted Venmo account to send money to his granddaughters, Jimmy Kimmel said on Kimmel Live. "It's just weird to hear about a politician using Venmo to pay teenagers for something other than sex, isn't it?"

Kimmel also lingered on a new 60 Minutes report on UFOs. "The government calls them Unidentified Aerial Phenomena, UAP — just like the Cardi B song — and they've known about this for a couple years but they waited until now to talk about it," he said. "I feel like if this story had been on 60 Minutes in, like, 1988, it would be the only thing we talk about for the next 30 years," but after watching it, "you almost hope they're visitors from another planet, because if China has technology like this, we'd better learn to speak Mandarin like immediately." Peter Weber