If there's one thing many athletes at the Olympics in Tokyo deserve medals for, it is good mask-wearing behaviour in public.
At public appearances and in interviews, athletes have worn what appear to be the better protective masks available to the public: N95 respirators with the bands around the head and neck and close-fitting KN95s with elastic loops around the ears.
There are also some disposable surgical masks on show, which are at least better than the homemade garden variety of masks people were encouraged to use last year.
It's out of necessity. The Games are without doubt a real-life experiment in what happens when you bring thousands of people together from countries across the globe in the middle of a pandemic, with some infected and unvaccinated.
Whether they have vaccinated protection or not, jabs aren't the end to the measures people can take to boost their odds of avoiding Covid-19.
And the athletes, support staff, officials and media are all having to be alert to the threat around them in a way New Zealanders have rarely had to before. The New Zealand team's masks are made by Auckland company Lanaco with wool-based filters.
The world has until now been missing an event that everyone tunes into where there is mandatory, and correct, masking on view by sporting heroes.
No, they can't wear masks when performing and the face coverings are allowed to be removed for official podium photos.
But wearing highly protective masks - without nose-slippage or under-chin tucking or one-ear-hanging sloppiness - is a welcome example.
Just how welcome was outlined by the United States Centres for Disease Control and Prevention on Saturday. The CDC is now recommending that fully vaccinated Americans wear masks indoors in areas of the country with high Covid spread.
A study had shown that the Delta variant of the coronavirus produced similar amounts of the virus in both the vaccinated and unvaccinated when they are infected.
Vaccination makes it less likely that people will become infected, even with Delta, and far less likely that it will turn out badly with hospitalisation and death. However, this data appears to be some evidence that vaccinated people can transmit it even if they are not nearly as contagious.
CDC director Dr Rochelle Walensky said: "High viral loads suggest an increased risk of transmission and raised concern that, unlike with other variants, vaccinated people infected with Delta can transmit the virus."
The study involves 469 people infected in Massachusetts. Of them, 346 had been fully vaccinated and 79 per cent had symptoms. The viral loads were similar among 127 fully immunised cases and 84 people either unvaccinated, partially vaccinated or their status was unknown. There were no deaths.
Before Delta, fully vaccinated people tended to carry less virus and suffer milder symptoms if infected, suggesting spread was less likely. Chinese scientists have said Delta has a much higher viral load. The CDC says more investigations are needed but that most transmission is occurring in and through unvaccinated people.
"Full vaccination is very protective, including against Delta," said Angela Rasmussen, a research scientist at the University of Saskatchewan in Canada. "Masks are a wise precaution, but the bulk of transmission is among the unvaccinated and that's still who is most at risk."
Official advice to people needs to keep pace with it - and that's a challenge for New Zealand, locked in our bubble. For us, future reopening restrictions will at the least need to combine good-quality masks with vaccinations and testing.
The variant is out there, it's just that most of us aren't out there mixing with it yet.
The Kiwi Olympians are getting a short taster of navigating life with it around, which more of us will need to do before long.