History

2019

Based on the retrospective analysis, starting from December 2019, the number of coronavirus cases in Hubei gradually increased, reaching 60 by 20 December and at least 266 by 31 December. That same day, the WHO received reports of a cluster of viral pneumonia cases of an unknown cause in Wuhan, and an investigation was launched at the start of January 2020.

According to official Chinese sources, these early cases were mostly linked to the Huanan Seafood Wholesale Market, which also sold live animals. However, in May 2020, George Gao, the director of the Chinese Center for Disease Control and Prevention, said animal samples collected from the seafood market had tested negative for the virus, indicating the market was not the source of the initial outbreak.

On 24 December 2019, Wuhan Central Hospital sent a bronchoalveolar lavage fluid (BAL) sample from an unresolved clinical case to sequencing company Vision Medicals. On 27 and 28 December, Vision Medicals informed the Wuhan Central Hospital and the Chinese CDC of the results of the test, showing a new coronavirus. A pneumonia cluster of unknown cause was observed on 26 December and treated by the doctor Zhang Jixian in Hubei Provincial Hospital, who informed the Wuhan Jianghan CDC on 27 December.

On 30 December 2019, a test report addressed to Wuhan Central Hospital, from company CapitalBio Medlab, stated that there was an erroneous positive result for SARS, causing a group of doctors at Wuhan Central Hospital to alert their colleagues and relevant hospital authorities of the result. Eight of those doctors, including Li Wenliang (who was also punished on 3 January), were later admonished by the police for spreading false rumours; and another doctor, Ai Fen, was reprimanded by her superiors for raising the alarm. That evening, the Wuhan Municipal Health Commission issued a notice to various medical institutions about "the treatment of pneumonia of unknown cause". The next day, the Wuhan Municipal Health Commission made the first public announcement of a pneumonia outbreak of unknown cause, confirming 27 cases—enough to trigger an investigation.

2020

During the early stages of the outbreak, the number of cases doubled approximately every seven and a half days. In early and mid-January 2020, the virus spread to other Chinese provinces, helped by the Chinese New Year migration and Wuhan being a transport hub and major rail interchange. On 20 January, China reported nearly 140 new cases in one day, including two people in Beijing and one in Shenzhen. A retrospective official study published in March found that 6,174 people had already developed symptoms by 20 January (most of them would be diagnosed later) and more may have been infected. A report in The Lancet on 24 January indicated human transmission, strongly recommended personal protective equipment for health workers, and said testing for the virus was essential due to its "pandemic potential".

On 30 January 2020, with 7,818 confirmed cases across 19 countries, the WHO declared the outbreak a Public Health Emergency of International Concern (PHEIC), and then a pandemic on 11 March 2020 as Italy, Iran, South Korea, and Japan reported increasing numbers of cases. Later that month, the number of cases outside of China quickly surpassed the number of cases inside China.citation needed

On 31 January 2020, Italy had its first confirmed cases, two tourists from China. As of 13 March 2020, the WHO considered Europe the active centre of the pandemic. On 19 March 2020, Italy overtook China as the country with the most reported deaths. By 26 March, the United States had overtaken China and Italy with the highest number of confirmed cases in the world. Research on coronavirus genomes indicates the majority of COVID-19 cases in New York came from European travellers, rather than directly from China or any other Asian country. Retesting of prior samples found a person in France who had the virus on 27 December 2019 and a person in the United States who died from the disease on 6 February 2020.

On 11 June 2020, after 55 days without a locally transmitted case being officially reported, the city of Beijing reported a single COVID-19 case, followed by two more cases on 12 June. As of 15 June 2020, 79 cases were officially confirmed. Most of these patients went to Xinfadi Wholesale Market.

On 29 June 2020, WHO warned that the spread of the virus is still accelerating as countries reopen their economies, although many countries have made progress in slowing down the spread.

On 15 July 2020, one COVID-19 case was officially reported in Dalian in more than three months. The patient did not travel outside the city in the 14 days before developing symptoms, nor did he have contact with people from "areas of attention."

In October 2020, the WHO stated, at a special meeting of WHO leaders, that one in ten people around the world may have been infected with COVID-19. At the time, that translated to 780 million people being infected, while only 35 million infections had been confirmed.

In early November 2020, Denmark reported on an outbreak of a unique mutated variant being transmitted to humans from minks in its North Jutland Region. All twelve human cases of the mutated variant were identified in September 2020. The WHO released a report saying the variant "had a combination of mutations, or changes that have not been previously observed." In response, Prime Minister Mette Frederiksen ordered for the country – the world's largest producer of mink fur – to cull its mink population by as many as 17 million.

On 9 November 2020, Pfizer released their trial results for a candidate vaccine, showing that it is 90% effective against the virus. Later that day, Novavax entered an FDA Fast Track application for their vaccine. The November 9 announcement does not mean the vaccine is about to be released. However, virologist and U.S. National Institute of Allergy and Infectious Diseases director Dr. Anthony Fauci indicated that the Pfizer vaccine targets the spike protein used to infect cells by the virus. Some issues left to be answered are how long the vaccine offers protection, and if it offers the same level of protection to all ages. Initial doses will likely go to healthcare workers on the front lines.

On 9 November 2020 the United States surpassed 10 million confirmed cases of COVID-19, making it the country with the most cases worldwide by a large margin.

As of 21 November 2020, more than 57.9 million cases have been reported worldwide due to COVID-19; more than 1.37 million have died and more than 37 million have recovered.