Dr. Anthony Fauci, the top U.S. infectious disease expert, said the nation should consider a vaccination mandate for domestic air travel, signaling a potential embrace of an idea the Biden administration has previously eschewed, as COVID-19 cases spike. Fauci, President Joe Biden’s chief science adviser on the pandemic response, said on Monday that such a mandate might drive up the nation's lagging vaccination rate as well as confer stronger protection on flights, for which federal regulations require all those age 2 and older to wear a mask. “When you make vaccination a requirement, that’s another incentive to get more people vaccinated," Fauci told MSNBC. “If you want to do that with domestic flights, I think that’s something that seriously should be considered.” Read:US officials recommend shorter COVID isolation, quarantine The Biden administration has thus far balked at imposing a vaccination requirement for domestic air travel. Two officials said Biden’s science advisers have yet to make a formal recommendation for such a requirement to the president. The officials, who spoke on condition of anonymity to discuss internal deliberations, said a vaccine mandate on planes could trigger a host of logistical and legal concerns. The U.S. currently mandates that most foreign nationals traveling to the U.S. be fully vaccinated against the coronavirus, though citizens and permanent residents only need to show proof of a negative test taken within a day of boarding. Federal rules don’t require people travelling by air within the U.S. to show a negative test. Hawaii requires travelers to test or show proof of vaccination to avoid a mandatory quarantine. Biden did not respond to questions on whether he was considering implementing a domestic air travel vaccination requirement, but he told reporters the subject was discussed on a call with the nation's governors Monday morning. “They asked Dr. Fauci some more questions about everything from whether or not he thought he was going to move to test at home — I mean, on air flights and that kind of thing,” Biden said of the call before departing the White House for his home in Rehoboth Beach, Delaware. During the virtual meeting with governors, Biden pledged the full support of the federal government to states facing surges in COVID-19 cases from the more-transmissible omicron variant and a run on at-home tests that dominated headlines over the holiday season. “My message is: If you need something, say something, and we’re going to have your back any way we can," Biden said. He acknowledged long lines and chaotic scenes as Americans sought out testing amid the case surge and as they looked to safely gather with family and friends over the holiday. “Seeing how tough it was for some folks to get a test this weekend shows that we have more work to do,” he said. He referenced his administration’s plan to make 500 million rapid tests available to Americans beginning next month through an as-yet-to-be-developed website. Arkansas Gov. Asa Hutchinson, the National Governors Association chairman, raised concerns Biden's plan could get in the way of state efforts to boost supply of tests. “That dries up the supply chain for what we might offer as governors,” he said, saying the lack of supply “has become a real challenge.” Biden assured Hutchinson that the federal effort won’t interfere with state actions. “This gets solved at the state level,” he said. A White House official said the new tests would come from new manufacturing capacity and wouldn’t interfere with existing supply chains. Earlier this year the White House explored a domestic vaccination requirement for flights, or one requiring either vaccination or proof of negative test. But officials have not been eager to mandate vaccination for domestic air travel because they expected it to face immediate legal challenges, mitigating its potential effectiveness as a tool to drive up vaccinations. Pressed last week on why Biden had not mandated vaccinations for domestic air travel, White House press secretary Jen Psaki told MSNBC that “we know that masking can be, is, very effective on airplanes." Read: Biden signs $768.2 billion defense spending bill into law “We also know that putting in place that additional restriction might delay flights, might have additional implications,” she added. "We would do it, though, if the health impact was overwhelming. So we rely always on the advice of our health and medical experts. That isn’t a step at this point that they had determined we need to take.” Data from the Centers for Disease Control and Prevention show more than 241 million Americans, about 77% of the eligible population age 5 and over, have received at least one shot of a COVID-19 vaccine. Officials believe, though, that there is some overcount in the figures due to record-keeping errors in the administration of booster shots. Since the summer, the Biden administration has embraced various vaccination requirements as a way to get unvaccinated Americans to roll up their sleeves. It has instituted requirements that federal workers, federal contractors and those who work in health care get their shots, and that employers with 100 or more employees institute vaccination-or-testing requirements for their workers. Those vaccination requirements have been mired in legal wrangling, with the Supreme Court set to hear arguments Jan. 7 in cases seeking to overturn them.

Dr. Anthony Fauci, the government’s top infectious diseases expert, blasted Sen. Ted Cruz for suggesting that Fauci be investigated for statements he made about COVID-19 and said the criticism by the Texas Republican was an attack on science. “I should be prosecuted? What happened on Jan. 6, senator?” Fauci, who is President Joe Biden's chief medical adviser, said in an interview that aired Sunday on CBS’ “Face the Nation." It was a reference to the violent insurrection at the U.S. Capitol by supporters of then-President Donald Trump that was stoked as Cruz helped lead GOP objections to Congress' certifying the 2020 election results. Read: Delta variant: Fauci warns of more 'pain and suffering' ahead “I’m just going to do my job and I’m going to be saving lives, and they’re going to be lying,” Fauci said. Some Republicans, including Cruz and Sen. Rand Paul, R-Ky., have accused Fauci of lying to Congress when he denied in May that the National Institutes of Health funded “gain of function” research — the practice of enhancing a virus in a lab to study its potential impact in the real world — at a virology lab in Wuhan, China. Cruz has urged Attorney General Merrick Garland to appoint a special prosecutor to investigate Fauci’s statements. Fauci, the director of the National Institute of Allergy and Infectious Diseases, called the GOP criticism nonsense. “Anybody who’s looking at this carefully realizes that there’s a distinct anti-science flavor to this,” he said. Read: Fauci says US headed in ‘wrong direction’ on coronavirus Cruz and Paul say an October letter from NIH to Congress contradicts Fauci. But no clear evidence or scientific consensus exists that “gain of function” research was funded by NIH, and there is no link of U.S.-funded research to the emergence of COVID-19. NIH has repeatedly maintained that its funding did not go to such research involving boosting the infectivity and lethality of a pathogen. When asked in the CBS interview whether Republicans might be raising the claims to make him a scapegoat and deflect criticism of Trump, Fauci said, “of course, you have to be asleep not to figure that one out.”

The United States is in an “unnecessary predicament” of soaring COVID-19 cases fueled by unvaccinated Americans and the virulent delta variant, the nation’s top infectious diseases expert said Sunday. “We’re going in the wrong direction,” said Dr. Anthony Fauci, describing himself as “very frustrated.” Read:Natural origins theory of Covid-19 still the most likely: Fauci He said recommending that the vaccinated wear masks is “under active consideration” by the government’s leading public health officials. Also, booster shots may be suggested for people with suppressed immune systems who have been vaccinated, Fauci said. Fauci, who also serves as President Joe Biden’s chief medical adviser, told CNN’s “State of the Union” that he has taken part in conversations about altering the mask guidelines. He noted that some local jurisdictions where infection rates are surging, such as Los Angeles County, are already calling on individuals to wear masks in indoor public spaces regardless of vaccination status. Fauci said those local rules are compatible with the Centers for Disease Control and Prevention recommendation that the vaccinated do not need to wear masks in public. Read:Little new evidence emerges in US probe of Covid-19 origins More than 163 million people, or 49% of the total U.S. population, are fully vaccinated, according to CDC data. Of those eligible for the vaccine, aged 12 and over, the figure rises to 57%. “This is an issue predominantly among the unvaccinated, which is the reason why we’re out there, practically pleading with the unvaccinated people to go out and get vaccinated,” Fauci said. Fauci said government experts are reviewing early data as they consider whether to recommend that vaccinated individuals to get booster shots. He suggested that some of the most vulnerable, such as organ transplant and cancer patients, are “likely” to be recommended for booster shots. Read: China rebuffs WHO’s terms for further COVID-19 origins study He also praised Republicans, including Govs. Asa Hutchinson of Arkansas and Ron DeSantis of Florida, and the second-ranking House leader, Rep. Steve Scalise of Louisiana, for encouraging their constituents to get vaccinated. Their states have among the lowest vaccination rates in the country. “What I would really like to see is more and more of the leaders in those areas that are not vaccinating to get out and speak out and encourage people to get vaccinated,” Fauci said.

The natural origins theory of the novel coronavirus is still "the most likely," White House Chief Medical Advisor Anthony Fauci said recently.  "The most likely explanation is a natural evolution from an animal reservoir to a human," Fauci, also the director of the National Institute of Allergy and Infectious Diseases of the US, told the media Saturday. READ: Little new evidence emerges in US probe of Covid-19 origins Paul Offit, a member of the US Food and Drug Administration's vaccine advisory committee, echoed Fauci's remarks. "I think the chance that this was created by laboratory workers – that it was engineered – is zero." Meanwhile, the head of the World Health Organization (WHO) recently said it was "premature" to rule out a potential link between the Covid-19 pandemic and a laboratory leak. WHO Director-General Tedros Adhanom Ghebreyesus Thursday said getting access to raw data had been a challenge for the international team that travelled to China earlier this year to investigate the source of Covid-19. He said there had been a "premature push" to rule out the theory that the virus might have escaped from a Chinese government lab in Wuhan city – undermining the WHO' March report, which concluded that a laboratory leak was "extremely unlikely." The first human cases were identified in Wuhan. Tedros told reporters that the UN health agency is "asking China to be transparent, open and cooperate, especially on the information, raw data that we asked for at the early days of the pandemic." "I was a lab technician myself, I'm an immunologist, and I have worked in the lab, and lab accidents happen. It's common," he said. In recent months, the idea that the pandemic started somehow in a laboratory – and perhaps involved an engineered virus – has gained traction, especially with President Joe Biden ordering a review of US intelligence to assess the possibility in May. China has struck back aggressively, arguing that attempts to link the origins of Covid-19 to a lab are politically motivated and has suggested that the outbreak might have started abroad. Most scientists suspect that the coronavirus originated in bats but the exact route by which it first jumped into people – via an intermediary animal or in some other way – has not yet been determined. It typically takes decades to narrow down the natural source of an animal virus like Ebola or SARS. "We need information, direct information on what the situation of this lab was before and at the start of the pandemic," the WHO chief said, adding that China's cooperation was critical. "If we get full information, we can exclude (the lab connection)." READ: 1st case of COVID-19 found in Tokyo Olympic village   Numerous public health experts have also called for an independent examination of Covid-19's origins, arguing the WHO does not have the political clout to conduct such a forensic analysis, and that the UN agency has failed after more than a year to extract critical details from China. Jamie Metzl, who has led a group of scientists calling for a broader origins investigation, welcomed Tedros' comments but said it was "deeply unfortunate and dangerous" that there were no current plans for a probe led by experts beyond the UN health agency, saying that China has repeatedly blocked requests for all relevant records and samples. Georgetown University law professor Lawrence Gostin, an expert in public health law, said Tedros' unusual plea for Chinese cooperation underlines how weak the WHO is. "It has no power or political heft to demand access to information critical for global health." Any WHO-led mission to China also requires government approval for all experts who travel to the country, as well as permission to visit field sites and final approval on any trip report. Tedros' appeal for transparency was echoed by German Health Minister Jens Spahn, who urged Chinese officials to allow the investigation into the origins of the virus to proceed. READ: India's health ministry says not enough evidence to link COVID-19 with increase in TB "We do appreciate the cooperation of the Chinese government so far for the first mission. But that's not yet enough," he said.

Once dismissed by most public health experts and government officials, the hypothesis that COVID-19 leaked accidentally from a Chinese lab is now receiving scrutiny under a new U.S. investigation. Experts say the 90-day review ordered on May 26 by President Joe Biden will push American intelligence agencies to collect more information and review what they already have. Former State Department officials under President Donald Trump have publicly pushed for further investigation into virus origins, as have scientists and the World Health Organization. Many scientists, including Dr. Anthony Fauci, say they still believe the virus most likely occurred in nature and jumped from animals to humans. Virus researchers have not publicly identified any key new scientific evidence that might make the lab-leak hypothesis more likely. Virologists also say it is unlikely that any definitive answer about virus origins will be possible in 90 days. The work to fully confirm origins and pathways of past viruses — such as the first SARS or HIV/AIDS — has taken years or decades. Read: ‘This IS INSANE’: Africa desperately short of COVID vaccine A look at what is known about the U.S. investigation of the virus. WHAT ARE INTELLIGENCE AGENCIES REVIEWING? Biden ordered a review of what the White House said was an initial finding leading to “two likely scenarios,” an animal-to-human transmission or a lab leak. The White House statement says two agencies in the 18-member intelligence community lean toward the hypothesis of a transmission in nature; another agency leans toward a lab leak. One document drawing new attention is a State Department fact sheet published in the last days of Trump’s administration. The memo notes that the U.S. believes three researchers at a Wuhan, China, lab sought medical treatment for a respiratory illness in November 2019. However, the report is not conclusive: The origin and severity of the staffers’ illness is not known — and most people in China regularly go to hospitals, not primary-care physicians, for routine care. The memo also pointed to “gain of function” studies — which in theory could enhance the lethality or transmissibility of a virus — allegedly done at the Wuhan lab with U.S. backing. However, National Institutes of Health Director Francis Collins has since adamantly denied that the U.S. supported any “gain-of-function” research on coronaviruses in Wuhan. David Feith, who served as deputy assistant secretary of state for East Asian and Pacific Affairs under Trump, said he supported Biden’s call for an enhanced review. “Implicit in the president’s statement is that there is more to analyze and more to collect than has been analyzed or collected to date,” Feith said. The Director of National Intelligence declined to comment. IS CHINA HAMPERING INVESTIGATIONS? The White House statement criticized China for a lack of transparency, echoing previous criticisms by Democrats and Republicans. “The failure to get our inspectors on the ground in those early months will always hamper any investigation into the origin of COVID-19,” the White House said. The Associated Press has reported on China’s interference in the World Health Organization’s probes of the virus and its fanning of conspiracy theories online. China has also forced journalists to leave the country in recent years and silenced or jailed whistleblowers from Wuhan and elsewhere. The lack of transparency in China is a significant and familiar challenge. But that does not in itself signal that something in particular is being hidden. “The problem is when you make that announcement (Biden’s call for investigation) in a highly politicized environment, it makes it even less likely that China will cooperate with efforts to find the origins of the virus,” said Yanzhong Huang, a senior fellow for global health at the Council on Foreign Relations. Read: WTO panel considers easing protections on COVID-19 vaccines WHAT DO SCIENTISTS BELIEVE ABOUT VIRUS ORIGINS? The most compelling argument for investigating the possibility of a lab leak is not any new hard evidence, but rather the fact that another pathway for virus spread has not been 100% confirmed. “The great probability is still that this virus came from a wildlife reservoir,” said Arinjay Banerjee, a virologist at the Vaccine and Infectious Disease Organization in Saskatchewan, Canada. He pointed to the fact that spillover events – when viruses jump from animals to humans – are common in nature, and that scientists already know of two similar beta coronaviruses that evolved in bats and caused epidemics when humans were infected, SARS1 and MERS. However, the case is not completely closed. “There are probabilities, and there are possibilities,” said Banerjee. “Because nobody has identified a virus that’s 100% identical to SARS-CoV-2 in any animal, there is still room for researchers to ask about other possibilities.” HOW LONG DOES IT TAKE TO CONFIRM THE ORIGIN OF A VIRUS? Confirming with 100% certainty the origin of a virus is often not fast, easy, or always even possible. For example, scientists never confirmed the origin of smallpox before the disease was eradicated through a global vaccination program. In the case of Severe Acute Respiratory Syndrome (SARS) – a disease caused by a beta coronavirus, like the current coronavirus – researchers first identified the virus in February 2003. Later that year, scientists discovered the likely intermediary hosts: Himalayan palm civets found at live-animal markets in Guangdong, China. But it wasn’t until 2017 that researchers traced the likely original source of the virus to bat caves in China’s Yunnan province. HOW IMPORTANT IS IT TO UNDERSTAND THE ORIGIN? From a scientific perspective, researchers are always keen to better understand how diseases evolve. From a public health perspective, if a virus has transitioned to being spread mostly by human-to-human contact, discovering its origins is not as essential to strategies for containing the disease. “Questions of origins and questions of disease control are not the same thing once human-to-human transmission has become common,” said Deborah Seligsohn, an expert in environment and public health at Villanova University. Republicans have pressed for more inquiries into a possible lab leak as part of a broader effort to blame China and vindicate Trump’s handling of the pandemic. Nearly 600,000 people in the United States have died of COVID-19, the highest toll of any country. Read:US to swiftly boost global vaccine sharing, Biden announces WHAY HAPPENS AFTER THE 90 DAYS? Many scientists caution that it’s unlikely a 90-day investigation will yield definitive new answers. “We rarely get a ‘smoking gun,’” said Stephen Morse, a disease researcher at Columbia University. “Even under the best of circumstances we rarely get certainty, just degrees of likelihood.” Any findings will likely be politically explosive, especially if new evidence comes to light supporting or dismissing the zoonotic transfer or lab-leak theory. And a failure to reach definitive conclusions, almost inevitable after a 90-day review, could provide grist for Trump supporters and opponents alike, as well as embolden conspiracy theorists. Meanwhile experts like the Council on Foreign Relations’ Huang suspect China may simply clamp down more, adding another complication to already tense relations. “This will likely make it even more challenging to extract concessions from China to allow another team to visit Wuhan, or have unfettered access to investigate there,” he said.

More than a month after the election, top Republicans finally acknowledged Joe Biden as the next US president on Tuesday.

Anthony Fauci, a top U.S. infectious disease expert, said on Friday that he has accepted President-elect Joe Biden's offer to be his chief medical adviser.