Covid-19 disease (novel coronavirus)


JANUARY 9, 2020 - DISCOVERY OF A NOVEL CORONAVIRUS (SARS-CoV-2). This virus is responsible for the infectious respiratory disease called Covid-19.

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Updated on Sept. 16, 2020, at 3:00 pm 

Since mid-August, the WHO* has been doing weekly updates with changes in the number of cases and the number of deaths from one week to the next one.

See all figures, everyday, on WHO website

In France, a mathematical model by the Institut Pasteur suggests that between 3 and 7% of the French population would have been affected by SARS-CoV-2 as of May 11, 2020.
The French public health agency Santé publique France** regularly updates key figures and the evolution of Covid-19 in France and around the world (in French). The national agency announces the number of Covid-19 confirmed cases (underestimated because only among people who have been tested), but also and especially people currently hospitalized including those in intensive care, the number of deaths, Covid-19 clusters under investigation, French departments in vulnerable situations, etc. 

Some key dates

After an epidemic outbreak in China in January and February, during the weekend of February 22-23, 2020, the epidemic situation evolved worldwide with the intensification of outbreaks in South Korea, Japan, and Singapore, and the appearance of new outbreaks in Iran and Italy. In these countries, we are witnessing a community transmission with no identified link with cases imported from China.

By the end of February, 2020, two months after its appearance in China, the epidemic seemed to have peaked there. On March 9, 2020, the Chinese authorities announced the reopening of some public places and the closure of field hospitals, while the number of new cases is sharply decreasing in the country.

On March 10, 2020, all countries of the European Union are now affected by Covid-19.

On March 11, 2020, the WHO announced that Covid-19 could be described as a pandemic, the first triggered by a coronavirus.

On March 14, 2020, France entered the "stage 3" of an active epidemic on its territory. To slow down dissemination on the territory and reduce the risk of tension on the hospital system for taking care of the most serious cases, social distancing measures are reinforced, with the closure of all places of non-essential groupings (cafes, restaurants, cinemas, discos...). Food stores, pharmacies, banks, tobacconists (newspaper sale points), petrol stations… remain open (with full stalls).

On March 16, 2020, the president of France decided to put in place measures to reduce social contact and restrict movement as much as possible. On March 17 at 12 noon, a containment system was put in place for the entire French territory for a minimum of 15 days. Movement was banned except in certain cases:  see

On March 16, the WHO counted almost as many cases inside China as outside of China: 165,515 cases were confirmed worldwide with 81,077 in China and 86,438 outside of China (in 143 different countries). 3,218 deaths were counted inside China and 3,388 outside of China. 

On March 23, 2020, in France, a law created a 'state of health emergency' to deal with the Covid-19 epidemic (see – page in French).

On March 27, 2020, in France, the confinement was extended until Wednesday, April 15.

On April 7, 2020, China recorded zero 24-hour deaths for the first time (source WHO). After midnight, on the night of Tuesday April 7 to Wednesday April 8, the barriers which closed the roads connecting Wuhan to the rest of China were lifted. Nearly 11 million Wuhan inhabitants and visitors had been confined to the epicenter of the coronavirus epidemic for seventy-six days.

On April 7, 2020, Singapore decided to completely contain its population, facing a second wave of infections. As one of the first places on the planet to detect cases of Covid-19, after its appearance in China, Singapore had managed to contain its spread thanks to a strategy of strict control and tracing of contacts with infected people.

On April 13, 2020, in France, the confinement was extended until Monday, May 11. The exit from from confinement will be progressive (read the opinion of Prof. Philippe Sansonetti "Covid-19 : chronique d’une émergence annoncée / sortie de confinement, ou la somme de tous les dangers" - in French).

On April 17, in China, the number of deaths attributed to Covid-19 climbed by almost 50%, going from 2,579 to 3,869. The Chinese authorities raise problems of information feedback and also of patients who, before February 20, were sometimes not tested or not taken care of by hospitals (source Le Monde - in French).

May 11, 2020, start of progressive enf of lockdown in France and extension of the 'state of health emergency' until July 10, 2020.

At the end of May, the United States counted more than 100,000 deaths due to Covid-19 (source WHO).

In early June, as the Covid-19 pandemic continues to decrease in Asia and Europe, the situation worsens in South America where the epidemiological curve is still rising sharply in many areas (see the Press Briefing of June 2, 2020 of Director of the Pan American Health Organization - PAHO).

On June 8, 2020, WHO Director-General Tedros Adhanom Ghebreyesus said at a virtual press conference in Geneva: "Although the situation in Europe is improving, globally it is worsening", thus alerting not to let go.

Read the update on the epidemic situation on June 10, in the Research Journal of the Institut Pasteur.


This pneumonia is an infectious disease caused by a virus belonging to the coronavirus family, currently referred to as SARS-CoV-2. The reservoir of the virus is probably of animal origin, even if SARS-CoV-2 is very close to a virus detected in a bat, the animal at the origin of the transmission to humans has not yet been definitely identified.


  • The duration of incubation is an average of 5 days, with extremes of 2 to 12 days. The onset of symptoms appears gradually over several days, unlike the flu which starts suddenly.
  • The first symptoms are not very specific: headache, muscle pain, fatigue/tiredness. Fever and respiratory signs occur secondarily, often two or three days after the first symptoms.
  • In the first descriptive studies from China, an average of one week elapsed between the onset of the first symptoms and admission to the hospital in the disease phase. At this stage, the symptoms combine fever, cough, chest pains and respiratory discomfort. The performance of a chest scanner almost always shows pneumonia affecting both lungs. Other clinical signs have been described since the first studies: signs of involvement of the central nervous system, expressed in particular in elderly people in the form of disorientation; sudden loss of taste and/or smell, events which occur in 30 to 50% of infected adults and which are very predictive of the diagnosis of Covid-19.
  • The severity of clinical signs requires that approximately 20% of patients remain in hospital and 5% require admission to intensive care. The most serious forms are observed mainly in people who are vulnerable because of their age (over 70) or associated diseases.
  • Specific observational studies (such as the one carried out on passengers on the Diamond Princess cruise ship) as well as modeling work have shown that the infection can be asymptomatic or paucisymptomatic (causing little or no clinical manifestations) in 30 to 60% of infected individuals, especially in young children (under 12).


Most of the initially described cases concerned people who had been to a market selling live animals. The leading hypothesis is therefore that the virus is a zoonosis (a disease transmitted by animals). Human-to-human transmission was established later and it is estimated that, in the absence of control and prevention measures, each patient infects between 2 and 3 people.

Transmission occurs mainly by air (droplets of postillions emitted during coughing efforts but also during speech) and passes through close contact (less than a meter) and lasting (at least 15 minutes) with a contagious individual. Smaller particles can also be emitted in the form of ‘aerosols’ during speech, which would explain why the virus can persist in suspension in the air, in an unventilated room (and justifies in these circumstances the wearing of a mask). Finally, the virus can retain infectivity for a few hours on inert surfaces from where it can be transported by hands, which justifies good hand hygiene.

How is it diagnosed?

There are two types of tests to break the transmission chains of the virus and control the evolution of the epidemic in France

  • Virological tests (RT-PCR) make it possible to determine whether a person is carrying the virus at the time of the test by means of a nasal or salivary sample.
  • Serological tests are used to find out if a person has developed an immune reaction after coming into contact with the virus.

Read the conditions to be tested on (in French)


Since the start of the epidemic and as of June 25, 2020, 41 RT-PCR tests and 80 serological tests have been evaluated by the national reference center (CNR Institut Pasteur and CNR associated laboratory of the Hospices Civils de Lyon). The reports of the evaluations carried out by the CNR have been communicated to the French health authorities, who are responsible for defining a validation methodology for these tests and for establishing a first list of validated in vitro diagnostic medical devices, based on the evaluations. of the CNR and the specifications of the High Authority for Health.

Read "Tests for the diagnosis of SARS-CoV-2 infections" (in French)

Precautions / Prevention

Barrier gestures are effective:

  • Wash your hands regularly (water + soap) or use a hydroalcoholic solution.
  • Cough or sneeze into the elbow, or into a tissue.
  • Avoid touching your face.
  • Use disposable tissues (and throw them in the trash after the first use).
  • Greet without shaking hands, without kissing.
  • Keep a distance of at least 1.5 meters with any contact person.

In the absence of treatment, the best protection for you and your loved ones is, at all times, compliance with barrier measures and physical distance. In addition, wear a mask when the distance of one meter cannot be respected.



There is currently no specific treatment – with demonstrated efficacy – against Covid-19. There is currently no specific treatment – with demonstrated efficacy – against Covid-19. Different medicines are in the process of being evaluated by way of clinical studies in which doctors are invited to ask patients with Covid-19 to participate. The French High Council for Public Health (Haut Conseil de la Santé Publique) issued an opinion on March 23, 2020 on the therapeutic recommendations for the management of Covid-19 (site in French.) (this opinion should be updated soon).

Instructions in France : “I have symptoms (cough, fever) that remind me of Covid-19: I stay at home, I avoid contact with others. I get in touch with my doctor who can offer me a consultation and a diagnostic test based on the symptoms I have.

If the symptoms worsen with breathing difficulties and signs of suffocation, I call the “SAMU-Center 15”; experts will decide what to do. (source in French”

Avoid contact with those around you. Do not go to your doctor or to the emergency room, to avoid any potential contamination. Limit travel to what is strictly necessary.

Some frequently asked questions (updated on June 25, 2020)

  • What is the animal reservoir?

A virus, 96% identical to SARS-CoV-2, has been identified in bats captured in China. The bat is therefore most likely the reservoir of the virus.

  • How is the virus transmitted from animals to humans?

It is likely that a mammal served as an intermediate host between the bat and man. This intermediate animal is not identified with certainty, but the pangolin is suspected.

  • Can the virus survive in the environment? And if so, for how long?

According to the available data, the survival of coronaviruses in the outdoor environment is only a few hours on dry inert surfaces. Standard hygiene measures (hand washing, surface cleaning) are effective. (Read also paragraph 'Transmission', above)
New studies* indicate a risk of transmission of the virus by airborne route, through microdroplets emitted during speech or bio-aerosols of viral particles in suspension, which can be increased in confined spaces.
* Source: K. A. Prather et al., Science 10.1126 / science.abc6197 (2020)

  • How long is the incubation?

The duration of incubation is an average of 5 to 6 days, with extremes of 2 to 12 days, which justifies the quarantine period of 14 days.

  • How is Covid-19 diagnosed in patients?

The diagnosis is suspected in front of signs of respiratory infection in a person returning from a place where the virus ​​circulates, in the 14 days preceding the symptoms onset, according to the case definition of Santé publique France.

  • What is the period of contagiousness?

Contagiousness begins on average 2 days before the onset of symptoms and up to 7-10 days after the onset of symptoms.

At the Institut Pasteur

In line with its mission to monitor influenza and respiratory viruses in France, the Institut Pasteur has mobilized its teams at the French National Research Center for Respiratory Viruses (Including Influenza) [page in French] and the Laboratory for Urgent Response to Biological Threats (CIBU) [page in French] to identify and confirm suspected cases of acute respiratory infection linked to the new coronavirus (SARS-CoV-2).

On Friday, January 24, 2020, the National Reference Center for Respiratory Infections Virus (including influenza) confirmed the first three cases of patients affected by the SARS-CoV-2 coronavirus on French territory. From these samples, the researchers were able to start sequencing the viral genome and have the complete sequence by Wednesday, January 29, allowing it to be compared with the twenty or so other sequences present in the world.

Learn more about whole genome sequencing of the novel coronavirus, SARS-CoV-2 (then called 2019-nCov).


At the same time, the National Reference Center continued its work on samples in order to rapidly isolate the virus and make it available to researchers. Cell culture is a crucial step to allow further research work.

Learn more about the isolation of Coronavirus SARS-CoV-2 (then called 2019-nCov) by researchers at the Institut Pasteur.


A Task Force has been set up at the Institut Pasteur (Paris) to respond to the urgency of this health crisis. This Task Force mobilizes the experts of the Institut Pasteur on various scientific areas:

  • Understanding more about the virus and its pathogenesis;
  • Developing new diagnostic tools and searching for antibodies that may have therapeutic applications;
  • Vaccine development;
  • Epidemiology and modeling to develop outbreak control strategies.
Coronavirus : toute l’actualité de l’Institut Pasteur sur COVID-19 - Institut Pasteur

All Covid-19 news from the Institut Pasteur



* To follow the latest news on the novel coronavirus, visit the World Health Organization website.

** To follow the evolution of current events in France, visit the website of the French Ministry in charge of health.

*** For the procedure to be followed in France, visit the Santé publique France website.

Set up on Saturday February 1st, a French freephone number for information on the coronavirus (0800 130 000)

Afaq iso 9001 - Institut Pasteur

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