US health officials have announced that vaccinated Americans no longer need to wear masks or social distance in most indoor settings - but many Americans remain confused as Covid-19 rules just became more complicated.
Last week, the US Centers for Disease Control and Prevention (CDC) changed their guidance on face masks, saying that fully vaccinated people no longer need them in most places.
It comes just over a year since the CDC first recommended that Americans cover their face and nose when in public and as new case weekly averages fall to lows not seen since last summer.
So far, nearly two dozen states, including the former global hot spot of New York, have started to change their virus mitigation rules to reflect the new CDC guidance.
Here's what the latest changes mean.
How will we know who is vaccinated?
According to the CDC, people who have gone two weeks since their final Covid vaccine jab no longer need to wear masks except in healthcare, prison or transportation settings. Physical distancing also is no longer necessary for the fully vaccinated.
But there's no way to know whether the mask-less shopper in your local supermarket aisle is fully vaccinated or choosing to forgo a mask for another reason.
Who can require proof of vaccination?
US officials have dismissed the idea of a "vaccine passport" to prove a person's jab history, saying it represents a violation of privacy.
That shifts the burden to local governments and businesses to determine whether to require proof of vaccination.
Already, several major businesses, including Walmart and Target, have been allowing shoppers to go unmasked without declaring their vaccination status.
But some concerts and other large gatherings have asked attendees for proof. Health experts warn that the black market for fake vaccination cards will balloon in the next few months.
Why did the CDC change the guidelines?
The CDC's advisory came after around half of Americans received their first jab, and as vaccinations opened up to children as young as 12. As of 19 May, around 37% of the US population has been fully vaccinated and about 60% of adults over 18 had gotten their first jab.
"I think the CDC realised that if they don't do something that sounds reasonable to people, then they've kind of lost the influence that the rules make sense," says Dr Gabor Kelen, director of the emergency medicine department at Johns Hopkins University.
"If the rules don't make sense, people are not going to follow the CDC anymore."
Herd immunity, which comes after 70%-90% vaccination, has already nearly been achieved among the elderly, he adds.
Overall herd immunity, however, may be more difficult to reach, experts say, due to factors including the emergence of new variants, lack of clarity as to how long individual immunity lasts, and the fact that no vaccine is entirely effective for all people.
The CDC's change is meant to serve as an incentive to get more people vaccinated, according to health officials. But Dr Kelen says that unofficially, the move was also made "to get out of the culture wars about masking and not masking" that divided the country during the Trump presidency.
According to US media, the change came abruptly and caught White House officials and state governors off guard.
Can you still carry Covid after being vaccinated?
Yes, but the chances are much lower, says Dr Kelen.
He adds that the vaccines have also been found to be extremely effective against the Covid variants.
But none of the vaccines offer 100% protection.
Those that still get sick after getting vaccinated usually only have minor symptoms, says Dr Kelen. He adds that the vaccinated are not considered to be major spreaders of the virus, according to the latest data.
When nine fully vaccinated baseball players for the New York Yankees tested positive for Covid, CDC director Dr Rochelle Walensky said the fact that only two experienced mild symptoms showed "this is the vaccine working".
Are unvaccinated people now more at risk?
As vaccinations continue, the risk for everyone, including unvaccinated people, drops every day.
But there's a chance that the loosening of mask rules will lead to other Covid precautions beginning to slide, as some unvaccinated individuals wrongly believe that is time for them to remove their masks too.
"There could be a misinterpretation or a sense of freedom of 'I don't need to do this stuff at all'," warns Dr Kelen.
For some he says, the new CDC guidance "is just a big excuse not to wear a mask in any situation".
This week, Texas banned local governments and public schools from issuing rules requiring masks, despite only 30% being fully vaccinated. Few children in Texas have yet to be vaccinated. On Thursday, Iowa lawmakers passed a similar measure.
On Wednesday, top US disease research Dr Anthony Fauci warned that the latest guidance was already being misused.
"I think people are misinterpreting, thinking that this is a removal of a mask mandate for everyone. It's not," Dr Fauci told Axios.
"It's an assurance to those who are vaccinated that they can feel safe, be they outdoors or indoors."
Why will some people keep wearing a mask?
People who are immunocompromised, ill, pregnant or being treated for a disease like cancer may continue wearing masks in public for some time.
Experts say Covid-19 will never be eradicated, but could eventually be somewhat controlled, like influenza which kills up 60,000 Americans each year.
Some Americans have said they plan to continue masking for years to come, regardless of the pandemic's timeline. Scientists say the number of common colds has dropped off a cliff since Americans began wearing masks - another reason people may keep masking in places like doctors offices and airports.
Others may keep masking due to persisting anxiety about the coronavirus, says Dr Steven Taylor, a clinical psychologist at the University of British Columbia, and author of the book The Psychology of Pandemics.
How might this affect mental health?
The new rule change could erode trust between fellow Americans, warns Dr Taylor, amid reports of Americans breaking the new honour system.
Polls have found that around 85% of Americans have abided by mask mandates. That figure is now sure to fall as restrictions vanish.
"If you're already anxious about being around people and you distrust people in your community, seeing someone's face and having them talk close to you is going to be an unsettling experience," says Dr Taylor.
"For other people, it's going to be a like a breath of fresh air. It's going to be like a whole new level of human contact."