Aerial photo taken on July 16, 2020 shows the Wan Chai of China's Hong Kong. (Xinhua/Lui Siu Wai)

Hong Kong started to loosen the COVID-19 lockdown for its citizens on Wednesday, months after the city began requiring all inbound people to undergo a 14-day quarantine in mid-March.

Return2hk is a travel scheme introduced by the Hong Kong SAR government that comes into effect on Wednesday and allows local residents in the neighboring Guangdong Province or Macao SAR to enjoy exemption from the two-week quarantine when returning to Hong Kong.

Those who would like to apply for exemption via the Return2hk scheme must fulfill certain conditions, including having a Hong Kong identity card and a valid negative COVID-19 nucleic acid test, said the Return2hk introduction released by the local government on its website.

Those eligible citizens can apply for an exemption through Return2hk's online booking system, which will open from 9:00 am on Wednesday through to 6:00 pm on Friday every week, the introduction said. The first batch of exemptions opened for booking on November 18 and will last until November 21 with 5,000 quotas available each day, it added.

The scheme excited many residents who are eager to return amid the pandemic. Hong Kong citizen Trexz (pseudonym), one of the earliest applicants who successfully booked an exemption before 10:00 am on Wednesday, said that the booking process was a "very easy" one.

"I'm not sure whether the system will be crowded in the future," Trexz told the Global Times. Having not returned to Hong Kong in a year, he said this time he applied to go back in order to see a lawyer there.

The scheme also benefits those citizens who would like to temporarily leave Hong Kong for Guangdong or Macao.

Li Xian, a woman working in the investment sector in Hong Kong whose family lives in Guangdong's Shenzhen city, was also among the earliest batch of applicants who completed the booking process on Wednesday morning within only 5-10 minutes of it opening.

Li said she eagerly wants to go to Shenzhen and reunite with her family there. "I haven't seen my parents for nine months," she told the Global Times.

Li still has to undergo a 14-day quarantine upon her arrival in Shenzhen based on the Chinese mainland's current policies. But she is fine with it, as she no longer needs to have two more weeks of quarantine when she decides to return to Hong Kong under the Return2hk scheme.

"In the past I would have been quarantined for a total of 28 days on both sides; but now only 14 days in total," Li said, adding that she can afford the shortened quarantine time with her annual leave.

Voices appealing for mainland cities to remove their current 14-day quarantine for visitors from Hong Kong were also heard from some local residents on Wednesday alongside the implementation of Return2hk.

But mainland-based virologists suggested against such appeals, saying it is untimely for the mainland to open to visitors from Hong Kong, where sporadic COVID-19 cases, including ones with unknown origins, occasionally occur.

"The approaching cold winter can also increase the occurrence of respiratory diseases, making the situation even more dangerous," said Yang Zhanqiu, a professor at the pathogen biology department under Wuhan University. He instead suggested that the mainland maintain its lockdown to Hong Kong until Chinese New Year in February 2021.

For those visitors from the mainland arriving in Hong Kong and holding negative COVID-19 tests, Yang said it is okay to exempt them from a 14-day quarantine. "The mainland is now generally safe after months of scientific, effective prevention and control of the coronavirus," he told the Global Times.