COVID-19

  • "Coronavirus disease 2019 (COVID-19)" is the disease caused by a new coronavirus called SARS-CoV-2.

  • The most common symptoms of COVID-19 include fever, dry cough and fatigue. Other symptoms include loss of taste or smell, nasal congestion, conjunctivitis, sore throat, headache, muscle or joint pain, skin rash, nausea or vomiting, diarrhoea, chills or dizziness. Some people may only have very mild or non-specific symptoms, while some may develop severe symptoms like shortness of breath, chest pain or confusion.

  • Complications may include respiratory failure, acute respiratory distress syndrome (ARDS), sepsis and septic shock, thromboembolism, and/or multi-organ failure including injury of the heart, liver or kidneys. There are reports that children and adolescents with COVID-19 may develop a rare but serious condition known as multisystem inflammatory syndrome in children (MIS-C), leading to multiorgan failure and shock.

  • People of older age and those with underlying medical problems (e.g. hypertension, heart and lung problems, diabetes, obesity or cancer) are at higher risk of developing serious illness.

  • According to the information from the World Health Organization (WHO), approximately 10-20% of people may continue to experience mid- and long-term effects of COVID-19, which are collectively known as “Post COVID-19 condition,” or “Long COVID”. Common symptoms of long COVID include fatigue, shortness of breath, cognitive dysfunction, headache, pain (e.g. chest pain, joint pain) and may have an impact on everyday functioning. There may be multi-organ effects or autoimmune conditions particularly in children. Symptoms may be new onset following initial recovery from an acute COVID-19 episode or persist from the initial illness. Symptoms may also fluctuate (change from time to time) or relapse (return of symptoms after period of improvement) over time. Although it is still unclear how long the symptoms may last, current research suggests that patients can improve with time. Some studies reported that long COVID is found more often in people who had severe COVID-19 illness, but anyone (including those with mild illness) can experience this condition after infected with COVID-19. According to WHO, COVID-19 vaccination can reduce incidence of long COVID. Some studies also suggested vaccinated persons are less likely to develop long COVID even they get infected, compared to the unvaccinated.

  • Mode of transmission includes through respiratory droplets, contact of contaminated surfaces or objects, short-range aerosol or short-range airborne transmission. The virus can also spread in poorly ventilated and/or crowded indoor settings. Most estimates of the incubation period range from 1 to 14 days, and some variants, such as the Omicron variant, may have even shorter incubation period of around 3 days.

  • COVID-19 vaccines are effective to protect people against COVID-19 disease, in particular severe illness and death.

  • Vaccination is one of the tools in the overall public health response to COVID-19. The combination of non-pharmaceutical interventions (NPIs) with vaccination will allow for maximum protection against the virus.

  • With COVID-19 vaccines deployed, there is a need to continue NPIs, including social distancing, good hand hygiene and wearing a mask in public, to reduce the risk of virus transmission. NPIs should continue to be followed by vaccinated individuals, as well as those who have not yet been vaccinated.

  • For details on COVID-19 vaccination, please refer to thematic website for COVID-19 Vaccination Programme: www.covidvaccine.gov.hk