The Origin of COVID-19

Identified in China in January 2020, SARS-CoV-2 is a novel coronavirus that causes a disease known as COVID-19. Coronaviruses constitute a large family of viruses circulating among animals and humans, in whom they are most often associated with the common cold and mild flu-like symptoms. However, two coronaviruses have caused serious epidemics in humans: SARS (Severe Acute Respiratory Syndrome) in 2002–2003 and MERS (Middle East Respiratory Syndrome), first detected in 2012 (learn more about other coronaviruses). As with SARS and MERS, the coronavirus responsible for COVID-19 has an animal origin.

In France, the first cases of COVID-19 were detected in January 2020, and two months later, on March 11, the World Health Organization (WHO) declared a pandemic.

• For everything you need to know about the management of the COVID-19 pandemic in France, see the Pandemic tab.

Since its emergence, regular waves of COVID-19 have been observed, though it is still too early to identify any seasonal patterns.

A Mutating Virus

Numerous variants of SARS-CoV-2 have circulated in France since the virus emerged, and new variants continue to appear; however, the majority of them have no impact on public health. All variants are regularly assessed through risk analyses, and when a variant exhibits characteristics that increase its impact on public health—such as increased transmissibility, greater severity of infection, or immune escape—it is classified as a variant of concern.

How is the disease transmitted?

COVID-19 is a contagious viral infection, and a person can carry and transmit the virus without necessarily experiencing symptoms of the disease. SARS-CoV-2 spreads easily from person to person, particularly through respiratory secretions when sneezing or coughing. Crowded, enclosed spaces (subways, buses, schools, etc.) are conducive to the transmission of these viruses.

What are the symptoms of COVID-19?

The main symptoms of COVID-19, whether combined or isolated, are similar to those of acute respiratory infections:

• fever or feeling feverish, chills, sweating;

• respiratory symptoms: cough, shortness of breath, sore throat, chest tightness, cold-like symptoms;

• headaches, body aches, unusual fatigue;

• diarrhea;

• other symptoms more characteristic of the disease may be observed, such as loss of smell or taste

Recognizing these suggestive symptoms allows you to take appropriate measures to limit the risk of infection and transmission.

The Case of Long COVID

Infection with SARS-CoV-2 may be associated with the persistence or onset of long-term symptoms after infection in a number of people. This phenomenon is now known as “post-COVID-19 condition,” more commonly referred to as “long COVID.” According to the World Health Organization’s (WHO) consensus definition, it generally appears within 3 months of the initial SARS-CoV-2 infection and is characterized by symptoms persisting for at least 2 months that, on the one hand, cannot be explained by other diagnoses and, on the other hand, have an impact on daily life. The list of 25 eligible symptoms includes, among others: fatigue, cough, shortness of breath, malaise after exertion, intermittent fever, loss of taste or smell, depression, and cognitive dysfunction.

How can the disease be prevented?

Vaccination is the best means of protection against severe forms of COVID-19. The vaccine must be renewed every six months, particularly for people over 65 or with risk factors, pregnant women, and healthcare workers. This booster shot allows the most vulnerable individuals (people aged 80 or older; immunocompromised patients; residents of nursing homes and long-term care facilities) to get vaccinated again as early as three months after their last dose or their last COVID-19 infection, thereby strengthening their protection against the virus. Indeed, the vaccine’s protection tends to wane after a few months, particularly due to the virus’s constant genetic mutations.

Because vaccination primarily protects against severe forms of the disease, but not necessarily against infection and transmission, caution remains essential to protect oneself and those around you. To this end, adopting preventive measures—and in particular wearing a mask—is recommended as soon as symptoms appear.