A version of this story appeared in the March 26 edition of CNN’s Coronavirus: Fact vs. Fiction newsletter. Sign up here to receive the need-to-know headlines every weekday.

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Researchers say they have found evidence that coronavirus infects the mouth, including inside the cheeks, in the gums and in salivary glands. When people swallow infected saliva, they could be spreading the virus to other parts of their bodies, CNN’s Maggie Fox writes.

The study, detailed in the journal Nature Medicine on Thursday, may explain why so many people infected lose their sense of taste, and suggests the mouth is an important source of the spread of Covid-19. It was previously known that saliva testing was a good way to detect infection, but researchers hadn’t looked to see why.

“When infected saliva is swallowed or tiny particles of it are inhaled, we think it can potentially transmit SARS-CoV-2 further into our throats, our lungs, or even our guts,” said Dr. Kevin Byrd of the American Dental Association Science and Research Institute, who worked on the study.

The mouth, nose, sinuses, throat and lungs are connected, and the virus can spread across all those regions in mucus that drains or is coughed up. They checked samples of oral tissue from people who died of Covid-19 and found the virus in about half of the salivary glands they tested.

No longer working under the Trump administration, leading US health officials have revealed to CNN the challenges they faced during the nation’s fight against Covid-19 over the past year, including tension behind closed doors and a lack of preparedness. Here are some of the most haunting revelations from CNN’s new documentary, “COVID WAR: The Pandemic Doctors Speak Out”:

YOU ASKED. WE ANSWERED.

Q. Do my kids need to be vaccinated before going to summer camp?

A. Children may not need to be vaccinated for Covid-19 for parents to send them to camps or playgrounds this summer, Fauci told CBS News on Sunday. He has previously said that elementary school-aged kids likely won’t be inoculated until the first quarter of 2022, as vaccine developers continued to study their effects in children.

A new study suggests the Pfizer/BioNTech and Moderna Covid-19 vaccines used widely in the United States are at least effective for these women and even their unborn babies. Researchers at Massachusetts General Hospital, Brigham and Women’s Hospital and the Ragon Institute of MGH, MIT and Harvard looked at 131 women who received either of the shots. The vaccine-induced antibody levels were equivalent in pregnant and lactating women, compared to non-pregnant women, the study shows. The team also found that breastfeeding women passed protective antibodies to their newborns.

Send your questions here. Are you a health care worker fighting Covid-19? Message us on WhatsApp about the challenges you’re facing: +1 347-322-0415.

WHAT’S IMPORTANT TODAY

Dangerous variants could mean ‘all bets are off’ in US recovery

As US states relax restrictions and Americans start traveling again, medical experts are warning that the pandemic is far from over and that new variants threaten to derail progress in the country.

A rise in infection numbers in several states “tells us when we have a more contagious variant that all bets are off because it means that the activities that we thought were pretty low risk are now going to be higher risk,” CNN medical analyst Dr. Leana Wen told CNN’s Anderson Cooper on Thursday.

Paris hospitals could be overwhelmed amid Europe’s third wave  

President Joe Biden doubles vaccine target for first 100 days

The United States has one of the fastest vaccination rollouts in the world, with 133 million doses already administered. Building on that momentum, President Biden said Thursday his administration was aiming to have 200 million doses administered by the end of April, doubling his original target.

Signs of collapse across Brazil as Covid spirals out of control 

EU summit descends into squabbling as leaders dial up pressure on AstraZeneca and the UK

A summit that was supposed to push drug company AstraZeneca to speed up its deliveries of tens of millions of vaccines and pressure the UK into sharing doses made in the country was hijacked by Austrian Chancellor Sebastian Kurz, who demanded a greater share of shots for his people, creating an internal rift in the bloc.

‘I spent a whole year indoors and upstairs.’ Life during the pandemic for people with disabilities 

ON OUR RADAR

I Miss My Bar features the sounds of bartenders shaking cocktails and pouring drinks, people chatting and atmospheric night sounds.
  • Dutch people are partying like it’s 2019 as a government-backed experiment attempts to work out how the events industry can get back on its feet. 
  • The Pacific Island nation of Papua New Guinea only has about 500 doctors for a population of 9 million people. Now it’s dealing with a Covid outbreak. 
  • India sees a muted festival of Holi, the Hindu celebration of colors, on Monday as it experiences its sixth consecutive day of record-high Covid-19 cases during its second wave.  
  • Louisiana Rep.-elect Julia Letlow on Sunday urged Republicans to get vaccinated against the coronavirus, citing her own tragic experience of losing her husband. 

TODAY’S PODCAST

“Throughout the White House, there was a sense that I could not have access to national media. Now, I had no idea that people were requesting me until about November when someone wrote me directly and said, we have asked for you for weeks. And I was like, what?” — Dr. Deborah Birx, former White House Coronavirus Response Coordinator.

Birx’s tenure at the White House was contentious. Now, she tells her side of the story to CNN Chief Medical Correspondent Dr. Sanjay Gupta, for a behind-the-scenes look at what went wrong in the Trump administration’s response to the pandemic, and how that can inform public health strategy going forward. Listen now.