What is COVID-19?
COVID-19 is the disease associated with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). SARS-CoV-2 is a new strain of coronavirus that had not been identified in humans prior to December 2019. There are different types of coronaviruses and, although they mostly circulate among animals, some can also infect humans.
The COVID-19 outbreak that started in late 2019 was declared a pandemic by the World Health Organization (WHO) on 11 March 2020 (1). This is the first pandemic caused by a coronavirus.
What are the symptoms of COVID-19?
COVID-19 varies in severity from having no symptoms at all (being asymptomatic) to having:
- sore throat,
- change or loss of taste and/or smell,
- general weakness,
- muscle pains.
In serious cases, symptoms can include:
- severe lung infection,
- sepsis and septic shock – a generalised infection and inflammatory response,
all of which need specialised medical care and support.
A patient’s condition can deteriorate rapidly, often during the second week of disease.
What are the complications of COVID-19?
A percentage of those affected by COVID-19 will require hospitalisation, some even requiring intensive care, sometimes for extended periods. People developing severe respiratory symptoms may require mechanical ventilation support, which may make them more susceptible to secondary bacterial infections. In addition, COVID-19 patients can experience complications, such as strokes or heart attacks, due to increased coagulation. Some patients experience neurological symptoms, such as personality changes or changes in alertness.
Hospitalisation rates increase rapidly with age, in particular for those aged 60 years and above, and for those with underlying health conditions.
For COVID-19 cases, the risk of dying increases rapidly with age, and is substantially higher than for influenza. It is increasingly evident that some patients may suffer long-term effects from COVID-19 infection, including difficulty in breathing and an elevated heart rate.
How does COVID-19 spread?
While bats are believed to be the original host of the virus, the virus now spreads from person to person (human-to-human transmission).
It is currently estimated that if preventive measures are not taken, on average one infected person will infect between two and three other people.
The virus is transmitted mainly via respiratory droplets and aerosols when sneezing, coughing, or interacting with others in close proximity (usually less than two metres). These droplets can be inhaled, or they can land on surfaces that other people may come into contact with, causing them to become infected when they touch their nose, mouth or eyes. Transmission can also occur from a person who is infected two days before they begin showing symptoms.
The virus can survive on different surfaces for several hours (on copper or cardboard) or up to a few days (on plastic or stainless steel).
The average incubation period for COVID-19 (i.e. the time between exposure to the virus and onset of symptoms) is currently estimated to be around five to six days, but almost always between one and 14 days.
Who is at risk of COVID-19?
Everyone is at risk of getting COVID-19, with some population groups having a higher risk of developing severe disease. Symptoms in children tend to be less severe than in adults.
Crowded indoor environments provide opportunities for COVID-19 outbreaks, with prisons, migrant centres and food processing plants being examples of places where outbreaks have been reported. It is possible that cold and humid air enhances the risk of transmission.
Those groups at increased risk of developing severe COVID-19 disease are:
- people aged 60 years and above;
- people with underlying health conditions, such as obesity, hypertension, diabetes, cardiovascular disease, chronic respiratory disease, or weakened immune systems.
How can COVID-19 be prevented?
Vaccines to prevent COVID-19 first became available in the EU/EEA in late December 2020.
It is recommended to keep physical distance (a minimum of one or, ideally, two metres) from others in public places, and to avoid gatherings of large groups of people to reduce the risk of infection through respiratory droplets.
For an overview of actions that people and communities can take to help slow down the spread of COVID-19 see: Infographic: Non-pharmaceutical measures.
The virus enters the body via the eyes, nose or mouth, so it is important to avoid touching the face with unwashed hands. Handwashing with soap and water for at least 20 seconds, or cleaning the hands thoroughly with alcohol-based solutions, gels or tissues is recommended in all settings.
How is it treated?
Scientists and clinicians are studying several treatments for COVID-19.
Healthcare providers mostly treat COVID-19 symptoms rather than targeting the virus itself by offering supportive care (e.g. oxygen therapy, fluid management) for infected persons, which can be highly effective.
For severely and critically ill patients, a number of medicines are being tested to target the virus, but their use still needs to be assessed more thoroughly. Several international clinical trials are ongoing to assess the effectiveness of various medicines and antibodies.
For the latest information on COVID-19 treatments, visit the European Medicines Agency’s (EMA) website: Treatments and vaccines for COVID-19
- European Commission: Coronavirus response
- ECDC: The latest surveillance data: COVID-19 situation update worldwide
- ECDC: COVID-19 pandemic
- ECDC: Latest evidence on COVID-19
- ECDC: Q&A on COVID-19
- ECDC: High-risk groups for COVID-19
- ECDC: How to protect yourself and others
(1) WHO Director-General's opening remarks at the media briefing on COVID-19, 11 March 2020: https://www.who.int/dg/speeches/detail/who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-19---11-march-2020
Note: The information contained in this factsheet is intended for the purpose of general information and should not be used as a substitute for the individual expertise and judgement of a healthcare professional.
The EU is responsible for ensuring that safe and effective COVID-19 vaccines reach the public in the EU/EEA. The European Commission authorises COVID-19 vaccines, after evaluation by the European Medicines Agency (EMA) and consultation with the EU Member States. The first vaccines were given at the end of 2020.