The virus usually moves from one person to another with small drops made when coughing or sneezing. It mostly spreads when people are close to each other, which is why social distancing is encouraged. Coronavirus can also spread when people touch a surface with the virus, and then they touch their face. Common symptoms include fever, cough, and trouble breathing. The illness can worsen with pneumonia and acute respiratory distress syndrome. As of January 2021, a number of vaccines for COVID-19 have been developed, but only a few have been approved as safe for use. The first vaccine to be approved was created by Pfizer and BioNTech, followed by the Oxford / AstraZeneca vaccine. Vaccine distribution has begun in many countries in Europe, North America, South America and Asia. The United Kingdom was the first western country to administer a COVID-19 vaccine. No antiviral medicine for COVID-19 is available. Doctors usually give patients supportive therapy instead. People can avoid spreading the virus by regularly washing their hands, covering their mouth when coughing, maintaining distance from other people, staying away from crowds, wearing medical or cloth face coverings, and being alone for people who think they are infected, also known as quarantining.
The outbreak might be from a coronavirus that usually lives in bats. This infected another animal, possibly a pangolin. It then changed inside that other animal until it could infect humans. It possibly originated at a wet market, Huanan Seafood Wholesale Market. A 55-year-old person from Hubei province was the first human to contract the virus on November 17, 2019. A 61-year-old man who was a regular customer at the market was the first person to die from the virus on January 11, 2020. The exact origin of the virus is still unknown since the market in Wuhan sold a variety of live wild animals in cages. Chinese tourists have spread the virus by traveling to other countries and made it a worldwide pandemic.
Racism and xenophobia against Chinese people and Asians increased during the pandemic.
In November 2020, two companies, Pfizer and Moderna, said they had finished making COVID-19 vaccines. Both are over 90% effective. Two mRNA vaccines, one by Pfizer and one by Moderna, have been tested. Both were over 90% effective. Countries began planning to give the vaccine to many people.
The United States had the most deaths from the virus. More than 600,000 Americans died from the virus. California had the most COVID-19 cases in the country.
Epidemiology is the study of how diseases affect the health and illness of groups of people.
On 31 December 2019, Chinese health authorities reported to the World Health Organization (WHO) a cluster of viral pneumonia cases of unknown cause in Wuhan, and an investigation was launched in early January 2020.
On 9 June 2020, a Harvard University study suggested that COVID-19 may have been spreading in China as early as August 2019, based on hospital car park usage and web search trends.
Cases means the number of people who have been tested for COVID-19 and have tested positive. These cases are according to Johns Hopkins University.
Most people who contract COVID-19 recover. For those who do not, the time between the start of symptoms and death usually ranges from6 to 41 days, but most of the time about 14 days. This data are recorded by the WHO.
On 11 March 2020, the WHO said that the pandemic could be controlled.
According to the United States Centers for Disease Control and Prevention, COVID-19 makes people feel sick in different ways, but it usually affects the lungs. People usually cough and have difficulty breathing. They often also have a fever, chills, headache, pain in their muscles, or trouble tasting or smelling things, which can often be confused with the flu virus.
According to an April 2020 study by the American Gastroenterological Association, COVID-19 can make sick people vomit or have diarrhea, but this is rare. They said about 7.7% of COVID-19 patients vomited, about 7.8% had diarrhea and about 3.6% had pain in their stomachs.
In February 2020, the WHO announced a name for the disease caused by SARS-CoV-2: COVID-19. It replaced the name "2019-nCoV." "Covi" is for "coronavirus," "D" for "disease," and "19" for the year 2019-- the year it was first detected. They said they did not want the name to have any person, place, or animal in it because people might blame the disease on that place, person, or animal. For example, it did not use the word "Wuhan." They also wanted the name to be easy to say out loud.
According to an article in Market Watch dated on February 27, 2020, the overall case mortality rate in China was 2.3%. However, these results might be severely different between different age groups and between men and women. People over the age of 70 experienced a rate of mortality 4-5 times that of the average. Men were more likely to die than women (2.8% versus 1.7% for women) possibly due to lifestyle, such as it being more possible in men to drink and smoke, making the risk of having a respiratory illness more possible, and thus more vulnerable. These numbers were the conclusion of a study by the Chinese Center for Disease Control and Prevention using 72,314 COVID-19 cases in mainland China as of Feb. 11. At that point this was the largest sample of cases for such a study.
On March 5, 2020, the WHO released the case fatality rate.
COVID-19 did not affect everyone in each country the same way. As of May 2020, APM Research Lab said the death rate among black Americans was 2.4 times as high as for white Americans and 2.2 times as high as for Latino and Asian Americans. In July 2020, "The New York Times" printed data from the Centers for Disease Control showing that black and Latino Americans were three times as likely to become sick and twice as likely to die as white Americans. This was not only in large cities but also in rural areas. This was not only for old people but for people in all age groups. Native Americans were also more likely than whites to become sick and die. Asian Americans were 1.3 times as likely as whites to become sick.
Camara Jones, an epidemiologist who once worked for the Centers for Disease Control and Prevention said this was socioeconomic and not because of any natural difference in black and white people's bodies. In the United States, black citizens are more likely to work jobs where they serve the public directly and to ride on public transport rather than take their own cars to work. This makes them more likely to be infected than people who work in private offices or from home. Sharrelle Barber, an epidemiologist and biostatistician from Drexel University, also said black Americans can live in crowded neighborhoods where social distancing is harder to do and healthy food harder to find. Both Barber and Jones blamed the long history of racism in the United States for these things. Three senators, Kamala Harris, Cory Booker and Elizabeth Warren said the federal government should start recording the race of COVID-19 patients so scientists could study this problem.
In June, the Centers for Medicare and Medicaid Services (CMS) told the public that people using the United States' government's Medicare health program had different results depending on race. Four times as many black Medicare patients went to hospitals for COVID-19 than white Medicare patients. There were twice as many hospitalized Hispanic patients than white patients. There were three hospitalized Asian patients for every two hospitalized white patients. The head of CMS, Seema Verma, said this was mostly because of socioeconomic status.