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The 2019 Novel Coronavirus (2019-nCoV) is a respiratory illness first identified in Wuhan City, China. Symptoms include fever, cough, and shortness of breath. The virus can be spread person-to-person in close proximity or from contact with contaminated surfaces.

The World Health Organization (WHO) has declared the coronavirus outbreak a pandemic and has named the disease caused by the virus COVID-19. It is related to other coronaviruses such as SARS and MERS, but is not the same virus.

"The virus enters the body through the nose, mouth or eyes, then attaches to cells in the airways that produce a protein called ACE2," according to the New York Times in its explainer "How Coronavirus Hijacks Your Cells."

Infection by COVID-19 is rarely fatal, according to the WHO.

"It can be more severe for some persons and can lead to pneumonia or breathing difficulties," reads a statement on WHO's website. "Older people, and people with pre-existing medical conditions (such as, diabetes and heart disease) appear to be more vulnerable to becoming severely ill with the virus."

On February 13, 2020, the known worldwide death toll was being reported as "at least 1,357," with more than 60,000 confirmed cases (see below for recent numbers).

In March, large gatherings such as Austin's SXSW, Rome's marathon and St. Patrick's Day parades in Chicago, Dublin and Boston were cancelled. Students were sent home early or classes went online at MIT,  Harvard University and Cornell University.

On March 11, 2020, WHO declared the coronavirus outbreak a pandemic, with 118,000 cases in 114 countries, and 4,291 fatalities.

"The WHO had not declared a pandemic since 2009," according to the New York Times, "when it gave that designation to a new strain of H1N1 influenza." (The CDC estimated that between 151,700 and 575,400 people worldwide died from H1N1.)

Notable figures infected with the virus include Oscar-winner Tom Hanks, the UK's Prince Charles, actor Idris Elba and US Senator Rand Paul. On March 24, Tony Award-winning playwright Terrence McNally (Kiss of the Spider Woman) died of complications from COVID-19.

On March 24, the 2020 summer Olympics in Japan were postponed.

As of March 25, worldwide cases were being reported as 438,100 people infected with the virus, with a death toll of at least 19,641. In the US, there were 59,502 known cases, according to a New York Times database, and at least 804 deaths due to the pandemic.

In April, the US became the country with the most recorded COVID-19 cases, outpacing countries with larger populations. On April 9, the John Hopkins University reported 432,579 US cases and 14,830 deaths. Health officials recommended that people wear cloth masks and gloves when in public, in addition to social distancing and hand washing guidelines.

High-profile deaths from COVID-19 complications in April included folksinger John Prine, jazz musician Ellis Marsalis, Jr. and Mahmoud Jibril, the former Prime Minister of Libya.

As of April 9, worldwide cases totaled 1,503,900, with 89,931 confirmed COVID-19 deaths, according to Johns Hopkins University. In New York City, the death toll exceeded the number of people killed at the terrorist attacks on the World Trade Center on 9/11.

Those numbers would continue to grow. By April 29, the U.S. would have more than 1 million recorded COVID-19 cases, which accounted for a third of the worldwide total. The death toll in the U.S. would rise to more than 59,000, which surpassed the number of U.S. casualties in the Vietnam War.

Worldwide deaths, as of April 29, were recorded at 219,611.

On May 12, Dr. Anthony Fauci, director of the National Institute of Allergies and Infectious Diseases (NIAID), warned the U.S. Senate about the dangers of reopening the country too soon.

"There is a real risk that you will trigger an outbreak you may not be able to control," Fauci said, "[it] but could even set you back on the road to try to get economic recovery. It would almost turn the clock back instead of going forward."

In May and June, some countries—including the U.S.—began relaxing restrictions and reopening businesses. On June 22, the Washington Post updated its state-by-state overview of COVID cases and precautions. As testing becomes more widely available, and communities begin to emerge from the shut-down, cases several states reported both increasing numbers of cases and fatalities. Those states include: Arizona, Arkansas, California, North Carolina, South Carolina, Tennessee and Texas. For the first time since June 7, fatalities started to increase rather than follow a downward trend, according to the Post.

As of June 25, the worldwide COVID infection total was 9.49 million confirmed cases, including 484,155 deaths. In the U.S., confirmed COVID cases numbered 2.4 million, with 122,238 known deaths, according to Johns Hopkins University. Given those numbers, roughly 5% of all cases result in death.

In August, President Vladimir Putin announced the release of a COVID vaccine named Sputnik V, which had been fast-tracked through its trial process. In September, Russian scientists shared their data, which claimed that the vaccine was safe for test subjects and triggered an immune response, according to the New York Times. Whether Sputnik V actively prevents coronavirus infections has yet to be determined. Several other trials are in process.

In the fall, confirmed COVID cases reached more than 27.6 million worldwide with nearly a million deaths (898,757), as of September 9. Cases in the U.S. reached 6.3 million, with 189,972 deaths, according to Johns Hopkins University.


The Bulletin of the Atomic Scientists publishes stories about nuclear risk, climate change, and disruptive technologies. The Bulletin also is the nonprofit behind the iconic Doomsday Clock.