"We are not expecting passenger demand to return to 2019 levels until 2024," said Tjoeng.

In 2019, there were around 51 million intraregional visits within ASEAN and the industry would very much like to get some of those travelers back on the road.

CITS Travel in Singapore, for example, is "hoping for bookings starting on the second half of the year with the rolling-out of vaccines", said Director Paul Yip. "We have still not gotten any bookings."

The entire industry is certain that a bounce-back boom will happen, but opinions are divided as to when. Estimates range from later this year to 2024, depending on the availability of COVID-19 testing and the willingness of governments to open up.

Breakaway Travel International Ltd, a Hong Kong travel agency, lost about 90 percent of its business and currently has just 10 air ticket bookings, according to Director KP Chan. "We do not expect significant improvement in the current year but hope to gradually recover in 2022," Chan said.

But even when it rebounds, travel and tourism may have changed forever.

Pretty much the entire industry, from the large cruise lines and airlines to individual operators such as tour guides, will have to adapt. Airlines in countries like South Korea or Australia, for example, are offering "flights to nowhere"－basically touring countries from the sky. Individual tour operators have also had to change the way they do business, much like Blue Sky Escapes in Singapore did.

Kang Dong-won, a tour guide in Hong Kong, has taken to filming weekly virtual tours. He uploads them to his "Mr. Kang in Hong Kong" YouTube channel.

"I believe big-scale package tours are a thing of the past, as travelers will fear being in large groups even in a post-COVID-19 world," Kang said. "So even when tourists return, it will be in smaller groups and revenue will take a hit. This will probably make returning to being a full-time tour guide more difficult."

The domestic tourism industry on the Chinese mainland may be an exception, thanks to swift return to some kind of normalcy later in 2020.

The industry went through a blip in early 2021, when the government discouraged trips during Lunar New Year holiday, usually the busiest travel season of the year, after a small spike in COVID-19 cases.

Still, tourism revenue during the Lunar New Year in 2021 reached 301.1 billion yuan ($46.24 billion), higher than the 278.28 billion yuan the industry earned in 2020 when the pandemic lockdowns were in full force, but much lower than the 513.9 billion yuan the industry generated in 2019, according to data from China's Ministry of Culture and Tourism.

The China Tourism Academy now expects that 4.1 billion domestic trips will be made in the country this year, up 42 percent from last year.

Travel within China, and eventually out of the country, could lead the way to a global recovery. There were 155 million outbound international tourists from China in 2019, and many of them are eager to get back on the road. Chinese tourists are likely to pour hundreds of billions of dollars into economies around the world.

On March 8, China launched an International Travel Health Certificate that operates via WeChat and shows results of recent tests and vaccinations, but quarantine requirements remain in place.

With the many disparate efforts underway to kickstart the industry, any rebound may be uneven.

In a recent survey, the UNWTO found many industry experts do not expect the industry to return to pre-pandemic levels for two years and say COVID-19 testing, tracing and vaccination certificates will be key components of any rebound. Just 15 percent of respondents to the UNWTO survey expect a rebound next year and 43 percent expect it by 2023. Still, 45 percent of respondents to the same survey say 2021 will be better than 2020.

Despite the uncertainty about the future, it is impossible to ignore the pent-up demand for travel.

Chris Chuang, a lawyer and avid traveler, has not left Hong Kong for more than a year. He has not taken a plane out of the city or even a train into the Chinese mainland, and is eager to get back on the road.

"I love traveling and Italy and Japan are two of my favorite destinations," Chuang said. "I hope COVID-19 will be over very soon, as I had to cancel six trips in 2020 alone."

The writers are freelance journalists for China Daily.