When the Tokyo Olympics put out a call for volunteers, Nima Esnaashari signed up along with thousands of others in Japan eager to soak up the atmosphere of the world's biggest sporting event.

But the closer the Games get, the more anxious he's becoming about the risk of catching Covid-19. Like the majority of Japan's population, he hasn't been vaccinated and doesn't know if he'll receive a dose before the pandemic-delayed Games begin on July 23.

"I love the Olympics, but I don't want to get corona," said Esnaashari, a language teacher from Hyogo prefecture. "It's great to be part of something bigger than yourself, but there's a risk factor and at the current time it's very high."

Japan is fighting a fourth wave of Covid-19 and, though the virus isn't spreading as quickly as it was in May, around 2,000 new cases are being reported each day. Just weeks away from the Olympics, fewer than 10% of Japan's population has received at least one dose.

Taro Kono, Japan's vaccine minister, said Tuesday 800,000 doses are being administered daily, and the country should reach 1 million doses per day by the end of June. However, at that rate, fewer than 20% of Japan would be fully vaccinated by the time the Games begin.

Games organizers plan to vaccinate 18,000 Olympic workers, including referees, staff, doping testers, and some volunteers. But with some 70,000 volunteers, there won't be enough to go around. It is not clear how many of the volunteers will get a dose.

Of the 80,000 people who signed up to help at the Games, at least 10,000 have quit, mostly due to the pandemic. Esnaashari is still not sure if he'll pull out.

"If I was to go without being vaccinated, in the back of my mind I would be thinking 'am I going to get corona today, or is it going to be tomorrow?'"

Volunteers say they've been given little protection against Covid-19 beyond cloth masks, hand sanitizer and pamphlets instructing them to keep others at a safe 2-meter distance. The Olympic website encourages volunteers to take public transportation between their homes and Olympic venues.

Doctors are warning of the risks of having so many unvaccinated people moving in and out of the Olympic village. They fear the Olympics could push Japan's already overstretched medical system to the brink.

Volunteers are disillusioned

An army of enthusiastic volunteers has been key to the success of recent Olympic Games, helping to operate venues and assist spectators and athletes. Around 50,000 volunteers were recruited to support the 2016 Rio Games, although reports suggest thousands quit their roles due to long working hours.

Tokyo organizers say the recent withdrawal of around 10,000 volunteers in Japan won't impact operations because of other Covid-19 restrictions, including a ban on spectators meaning fewer overall numbers at the Games.

When college student Jun Hatakeyama signed up to volunteer at the Tokyo Olympics, he was filled with national pride -- excited to welcome the world's best athletes to his country.

But he says his enthusiasm slowly turned into anxiety and disillusionment as he witnessed one problem after another: from rising Olympic costs to sexist comments from the former head of the Tokyo Olympics, and now the decision to hold the Games from organizers barreling ahead with the event despite surging cases in Japan.

Hatakeyama has quit his role to make a statement.

"The Olympic Games is belittling human lives," he said. "Our lives are not normal, it's a state of emergency now. So why can we hold an Olympics 2020 now?"

"I think the meaning of the Olympic Games is completely forgotten."

But other volunteers are more sanguine, including Philbert Ono, a travel writer and photographer in Tokyo. "I believe all possible safety measures will be taken and I will also be following all protocols, so I'm confident that the risks will be very much reduced," Ono said.

Norihiko Tsuzuki, a graduate student in Japan, said he's still excited to work as an Olympic volunteer, despite the mounting challenges leading up to the Games. "I hope the obstacles Japan has faced will force the country to improve," he said.

A safe bubble?

Organizers insist the Olympics can be held in a safe bubble: athletes will be regularly tested, contact traced, and socially distanced. By the time the Games start, officials expect more than 80% of athletes to be vaccinated.

But public health experts say there are many ways for the bubble to be punctured, especially if tens of thousands of largely unvaccinated and untested volunteers are moving between Olympic venues.

"Even without spectators, it's not a bubble. There are too many leaks in it," said epidemiologist Mike Toole from the Burnet Institute in Melbourne, Australia.

"Having these 70,000 volunteers out in the community, moving from neighborhood to neighborhood, then going into the Games -- where you have around 20% unvaccinated -- then you're looking at a high-risk scenario."

The third and final Olympic Playbook of Covid-19 measures says some "sport specific" volunteers will be tested regularly at the Games, without specifying how many that would include.

Warnings from Japan's medical community continue to grow. The Tokyo Medical Practitioners Association, an organization representing 6,000 doctors in Tokyo, wrote a letter calling for the Games to be canceled.

"The most important priority now is to fight against COVID-19 and to secure people's lives and livelihoods," the letter said. "Japan will bear a big responsibility if the hosting of the Olympic and Paralympic Games contributes to the spread of COVID-19 and increases the number of sufferers and deaths."

The head of Japan's Covid-19 taskforce, Shigeru Omi, said earlier this month it's "not normal" to host the Olympics during the pandemic, warning the Games would have an impact on infections in Japan.

Japan's government is scheduled to end the state of emergency in Tokyo and several other prefectures on June 20, but is considering keeping some curbs such as on restaurant hours until the Olympics start in July, Kyodo News reported Tuesday.

Rolling out the vaccines

As the Olympics fast approaches, Japan is ramping up its vaccination plan.

But even if the country had the capacity to administer 1 million doses a day from tomorrow, it still faces the challenge of encouraging people to take the vaccine.

The rollout began in February with people aged 65 and over, but so far only around a third of all senior citizens have been vaccinated. Kono, the vaccine minister, acknowledged some people were reluctant to show their arm, and indicated part of the process would be encouraging people to take the shots.

"As it goes down, we are trying to reach younger generations; more and more people are not interested in vaccines, so how can we encourage them to get vaccinated," Kono said.

Large-scale coronavirus vaccination sites run by the state in Tokyo and Osaka will begin offering shots to younger people from across the country on Thursday, according to Japanese state broadcaster NHK.

Vaccinations are due to start at workplaces and universities next week, though some companies, such as Japanese airline ANA have started early.

Prime Minister Yoshihide Suga wants everyone who desires the vaccine to receive it by October or November.

Still, with five weeks to go before the start of the Olympics, the pressure is on to ensure the public that Tokyo is safe.

Language teacher Esnaashari said he was planning to stay with friends in the capital during the Olympics. Before the pandemic, he said they were willing, "but now it's like, 'Do I want to live with someone interacting with possibly thousands of people a day?'"

"At the very minimum, I would prefer if they're able to house the volunteers in designated hotels and give them the proper shuttle buses to the venues," he said.

Like Esnaashari, Barbara Holthus, a Tokyo Olympic volunteer and deputy director of the German Institute for Japanese Studies in Tokyo, is also considering dropping out of the Games.

"I need to protect myself. I need to protect my family. And if I think this is going to be dangerous to me and my family, I'm going to quit," Holtus said.

"It is absolutely the wrong time to hold a sporting event," she added. "It's absolutely the wrong message at a time when the world is suffering."