Overview

COVID-19 is the disease caused by the SARS-CoV-2 coronavirus. It usually spreads between people in close contact.

COVID-19 vaccines provide strong protection against severe illness and death. Although a person can still get COVID-19 after vaccination, they are more likely to have mild or no symptoms.

Anyone can get sick with COVID-19 and become seriously ill or die, but most people will recover without treatment.

People over age 60 and those with existing medical conditions have a higher risk of getting seriously ill. These conditions include high blood pressure, diabetes, obesity, immunosuppression including HIV, cancer and pregnancy. Unvaccinated people also have a higher risk of severe symptoms.

Symptoms

People may experience different symptoms from COVID-19. Symptoms usually begin 5–6 days after exposure and last 1–14 days.

The most common symptoms are:

• fever 
• chills
• sore throat.

Less common symptoms are:

• Muscle aches and heavy arms or legs
• Severe fatigue or tiredness
• Runny or blocked nose, or sneezing
• Headache
• Sore eyes
• Dizziness
• New and persistent cough
• Tight chest or chest pain
• Shortness of breath
• Hoarse voice
• Numbness or tingling
• Appetite loss, nausea, vomiting, abdominal pain or diarrhoea
• Loss or change of sense of taste or smell
• Difficulty sleeping.

People with the following symptoms should seek immediate medical attention:

• Difficulty breathing, especially at rest, or unable to speak in sentences
• Confusion
• Drowsiness or loss of consciousness
• persistent pain or pressure in the chest
• skin being cold or clammy, or turning pale or a bluish colour
• loss of speech or movement.
• People who have pre-existing health problems are at higher risk when they have COVID-19; they should seek medical help early if worried about their condition. These include people taking immunosuppressive medication; those with chronic heart, lung, liver or rheumatological problems; those with HIV, diabetes, cancer. obesity or dementia.
• People with severe disease and those needing hospital treatment should receive treatment as soon as possible. The consequences of severe COVID-19 include death, respiratory failure, sepsis, thromboembolism (blood clots), and multiorgan failure, including injury of the heart, liver or kidneys.
• In rare situations, children can develop a severe inflammatory syndrome a few weeks after infection. 
• Some people who have had COVID-19, whether they have needed hospitalization or not, continue to experience symptoms. These long-term effects are called long COVID (or post COVID-19 condition). The most common symptoms associated with long COVID include fatigue, breathlessness and cognitive dysfunction (for example, confusion, forgetfulness, or a lack of mental focus or clarity). Long COVID can affect a person’s ability to perform daily activities such as work or household chores.  

Treatment

Most people will recover without needing treatment in a hospital.

For those who need it, doctors will suggest treatments for COVID-19 based on the severity of the disease and the risk of it getting worse. They will consider the person’s age and if they have other health problems.

Prevention

People should get vaccinated as soon as it’s their turn. They should follow local guidance on vaccination and ways to protect themselves against COVID-19.

COVID-19 vaccines provide strong protection against serious illness, hospitalization and death.

To prevent the spread of COVID-19:

• avoid crowds and keep a safe distance from others, even if they don’t appear to be sick;
• wear a properly fitted mask if you feel sick, have been close to people who are sick, if you are at high-risk, or in crowded or poorly ventilated areas;
• clean your hands frequently with alcohol-based hand rub or soap and water;
• cover your mouth and nose with a bent elbow or tissue when you cough or sneeze;
• dispose of used tissues right away and clean your hands; and
• if you develop symptoms or test positive for COVID-19, self-isolate until you recover.

Vaccination against COVID-19 is based on priority groups such as people aged 60 years and over, and those with underlying medical problems such as high blood pressure, diabetes, chronic health problems, immunosuppression (including HIV), obesity, cancer, pregnant persons, and unvaccinated people. In March 2023, WHO updated its recommendations on primary series vaccination (two doses of any vaccine) as well as the need for booster doses. These recommendations are time-limited and can change at any time depending on how the SARS-CoV-2 virus is circulating in your area or country. It is important to stay up to date with local guidelines and recommendations provided by your local health authority.

Since its introduction, COVID-19 vaccines have saved millions of lives across the world by providing protection against severe disease, hospitalization, and death. Even though vaccines protect against severe disease and death, it is still possible to spread SARS-CoV-2 to others after being vaccinated.