As Olympic organisers deny reports that the Tokyo Games this summer will be postponed again, they, and other sports bodies, are wrestling with the issue of vaccinating participants for Covid-19 at international events.
On Monday, Denis Masseglia, the president of the French National Olympic Committee, said there was no choice but to vaccinate and that "holding the Games is at stake".
The International Olympic Committee (IOC) officially has been more cautious ahead of the Tokyo Games, scheduled for July 23 to August 8. It encourages the vaccination of athletes but says it cannot impose inoculation.
IOC president Thomas Bach has said there would be "neither a vaccine obligation nor a priority to athletes" for this summer's Olympics.
Bach cannot impose tests "for legal reasons", said Masseglia.
The Games will be on agenda of the IOC Executive Board on Wednesday.
"For those who do not wish to be vaccinated, it is important to know that the precautions for participation will be extremely tough," said Masseglia in a video press conference, warning of "quarantine of a fortnight" and "tests in the mornings and evenings."
While vaccination programmes are kicking into gear around the globe, they are still focusing on those facing the highest risk, so the question of whether elite athletes should be a priority is, for now, awkward.
"This is not an issue about the Olympics, it is about an issue of how we use a scarce resource to try and combat what has obviously been one of the most devastating health crises of our time," said World Health Organization senior advisor Bruce Aylward.
There is also the question of the impact of international visitors. In Japan, which reportedly plans to start mass vaccinations in May, a quarter of the population is over 65 and 12.5 percent are over 75.
The Olympics are not the only event facing these dilemmas in an international sports calendar filled with rescheduled events.
After a handful of people on three chartered flights taking tennis players to Melbourne ahead of next month's Australian Open returned positive Covid-19 tests, the local authorities ordered everyone on board into 14-day quarantine. Some 72 players remain in lockdown.
Turkmenistan, which claims to have no Covid-19 cases, said last week it plans to vaccinate foreign athletes competing in Davis Cup qualifying and at the Track Cycling World Championships in October. The Central Asian state said it would provide the vaccines for free and give athletes the choice of which type they want.
Japan is trying to balance safety against compulsory vaccination.
"We are considering comprehensive measures to hold a safe and secure game, even without making vaccines a condition," Katsunobu Kato, the Chief Cabinet Secretary, told a press conference last week.
Tokyo organisers say their Games has cost 1.64 trillion yen ($15.9 billion).
Bach has called the Games a "light at the end of the tunnel" for humanity and some in the industry argue they should go ahead.
Football's European championships, which like the Olympics were due to take place last year, are scheduled in June and July. No decision has yet been made about vaccinations and there is debate about whether to stick to the plan to play matches in 12 countries.
"It's too soon to take a decision," a UEFA spokesman told AFP, adding that the subject would come under "consideration for the medical protocol of the Euro".
'Not high risk'
Athletes and sports administrators have offered contrasting opinions.
"We're fairly young, fit people who would not be considered high risk for Covid," British Paralympic cyclist Neil Fachie told the BBC.
"The last thing you want to do is take a vaccine away from someone who needs it far more.
"Should we get offered the vaccine then I imagine I would take it, but there's definitely a question mark of am I really deserving or not?"
That view is shared by fencer Max Hartung who doubles up as chairman of the German Olympic Committee's Athletes' Commission.
"No athlete will tell someone who has a higher health risk that their sport is more important than someone else's life," said Hartung.
Steve Solomon, a 400-metre runner who is the captain of Australia's Olympic team, summed up the dilemmas.
"My preference would be to get vaccinated before I go to Japan, certainly," Solomon told The Guardian. "If I am not vaccinated by then, I will still go… I firmly believe that the vaccine needs to be given first to those parts of the population that are most vulnerable to the coronavirus. Athletes are not part of that population."
Former marathon world record holder Paul Tergat, now the head of the Kenyan Olympic committee, agrees.
"We want everyone going to Tokyo to get vaccinated early enough for them to be reassured," he said. "The sooner, the better."
Masseglia pointed out that the situation would have changed by the summer.
"It's out of the question that athletes should be given priority over other categories of population, but between now and the Games we can assume that it is possible to have them vaccinated without penalising other people," he said.
In Russia, the sports ministry told AFP that the plan to "vaccinate athletes of national teams" would be a priority for those "preparing to participate" in the Olympics. In theory, Russia's 'national teams' are banned from Tokyo.
The ministry said, however, that the vaccination programme would be "voluntary".