Timeline: Covid-19 in China

The earliest known cases of Covid-19 start exhibiting symptoms on Dec 8.

But whether the first known patient was a man surnamed Chen or an accountant, who was presented to be interviewed by World Health Organisation (WHO) investigators when they visited Wuhan in January 2021, has been the subject of dispute.

Both men had no links to a seafood market in the city where many of the early cases were detected.

Wuhan health authorities confirm they are battling an unknown virus and disclose that dozens working at a seafood wholesale market in the city are ill.

The Huanan Seafood Wholesale Market is ordered to close as scientists conduct investigations.

China reports its first Covid-19 death, just ahead of the Chinese New Year travel season in the country which is often seen as the world's largest annual human migration.

Across the country, people start stockpiling surgical masks, sanitiser and cold medicine, emptying shop shelves.

Chinese overseas, including in Singapore, follow suit, and send the products home.

The authorities order an overnight lockdown in Wuhan, effective some 10 hours after the announcement.

This gives time for some 10,000 people to leave the city and Hubei province, which has already reported a spike in cases.

As the number of cases in China mounts, reaching the thousands, the WHO declares a "public health emergency of international concern".

To avoid stigmatising people, places or animals linked to the pandemic, the novel coronavirus is named Covid-19, an abbreviation for coronavirus disease 2019.

As cases continue to mount globally, China announces the closure of its borders in a bid to contain the virus.

Three weeks earlier, the authorities had ordered 14 days of mandatory quarantine for anyone entering the country.

After 72 days, the lockdown in Wuhan is lifted.

The response to the virus will be repeated multiple times - albeit with slight modification - as the authorities refine the scale of the lockdowns to ensure minimal economic disruption, often confining restrictions to just districts or even housing compounds.

After nearly two months of no new local infections, a new cluster shows up in a wholesale market in the capital, Beijing. It spreads to several districts across the city, putting the capital on edge for several weeks.

President Xi Jinping hails China's success in fighting Covid-19 as cases surge worldwide.

In an elaborate ceremony at the cavernous Great Hall of the People, Mr Xi hands out awards to those who played an important role in fighting the pandemic, including respiratory diseases expert Zhong Nanshan and vaccine researcher Chen Wei.

After testing Covid-19 vaccines under an emergency use programme, China begins rolling out a mass vaccination programme.

Researchers picked by the WHO visit Wuhan for a virus origins investigation.

The issue has become increasingly politicised, with top government officials from China and the United States blaming the other side for being the source of the virus.

The WHO origins study, done in collaboration with Chinese scientists, is released.

It is inconclusive on whether the virus originated at the seafood market or had been leaked from a lab.

Sinopharm's vaccine is added to the WHO's vaccine emergency use list, paving the way for it to be recognised internationally. The Sinovac vaccine follows shortly thereafter.

A resurgence of cases triggers domestic travel restrictions across China.

After a worker at Nanjing airport is infected with the new and more infectious Delta variant, cases spread to at least 14 provinces and regions during the summer holiday season.

China says it has vaccinated more than a billion people. To date, 2.6 billion doses of the Covid-19 vaccine have been dispensed.

China reports its first case of the Omicron variant in the port city of Tianjin, an hour's drive from Beijing.

The authorities say the man who tested positive for the variant exhibited no symptoms and was quarantined upon arrival. They did not say where he came from.