Beijing says that it is adopting all necessary coronavirus safety measures for the 2022 Winter Olympics, which start next month.

So what is being planned for the Games, and how successful has China's policy of "zero Covid" been? China is going to great lengths to keep the virus out.

It has said that foreign spectators will be barred, with only residents of mainland China allowed in to events - they must also quarantine when they leave the venues to return home. People are advised not to travel into the capital from other parts of the country.

It has already created an Olympic bubble by keeping the media, athletes and observers in three distinct bubbles, with the rules saying anyone entering these bubbles must be fully vaccinated or spend 21 days in quarantine. Covid testing is carried out on a daily basis, and face masks are required at all times.

No-one can leave the bubbles. Overseas participants will enter them upon arrival in China, and remain in a bubble until they leave the country.

Local support workers, including volunteers, cooks and drivers, are also part of a sealed bubble. They'll have no physical contact with the outside world, even with their families.

This system applies not just to housing, hospitals and locations meant to serve the Olympics, but also transport links. There are closed-loop airports and high-speed rail systems (given that most major venues are outside of Beijing).

All designated vehicles for Olympic personnel are labelled with a special red sign on the front, and local traffic authorities have even advised the public to avoid contact if they have a road accident with them. Rubbish will be held at temporary storage sites, to prevent cross-infection.

Travel in and out of China is severely restricted for foreigners, and there have been restrictions on internal movement since the pandemic began. Any travellers from abroad who do have permission to enter China are screened on arrival, and sent to government-designated hotels for a mandatory quarantine of at least two weeks.

In most cities, this is followed by a further seven days of hotel or home quarantine, and then a seven-day monitoring period when social mixing is prohibited and regular reporting to local health officials is required. China has stopped issuing and renewing passports for non-urgent purposes to its own citizens both at home and abroad, to further minimise international travel.

There are also strict controls on moving between China's cities (and sometimes between individual neighbourhoods) with further mandatory periods of self-isolation for those permitted to travel. With the games approaching, China has put some cities into lockdown where cases have been detected.

During these, people are only allowed to leave for urgent matters, such as going to hospital. Surveillance by the police and local volunteers is also being stepped up, with harsh penalties for anyone breaking the rules.

Residents can be evicted from their homes at short notice and sent to quarantine facilities if infections are detected during a mass testing campaign. All non-essential businesses are shut, apart from food shops and some other essential suppliers.

Schools are closed and public transport is suspended, with almost all vehicle movement banned. On the face of it, China has had remarkable success containing the pandemic.

Since the end of 2019, China has reported just over 4,600 deaths (according to Our World in Data). In the United States, more than 830,000 have died and in the UK, just over 150,000. Per million people, that's around three deaths in China, compared with 2,500 in the US and 2,190 in the UK.

Reported infections in China have also been very low, rarely rising above 150 a day across the country throughout the pandemic. Concerns have been expressed about the accuracy of the official data, but it seems clear that both infection and death rates have been low when compared with other countries.

The National Health Commission in China says 85% of its population is now fully vaccinated. Despite this, China is almost alone in adhering to a zero-Covid policy regardless of the cost to personal freedoms and to the economy.

Other countries, such as Australia, New Zealand and Singapore, modified their strict adherence to zero Covid in the latter part of 2021. The Delta variant was taking hold anyway and these countries had also managed to push up their vaccination rates.

Cases did then rise in those three countries, but the hope is that sufficient vaccination will keep serious illness and death to manageable levels. In China's case, there must be concerns that the country could be at risk of widespread outbreaks were its strict controls lifted too quickly.