Background
 

In December 2019, clusters of pneumonia cases of unknown etiology were identified in Wuhan, Hubei Province, China. On January 30, 2020, the World Health Organization (WHO) declared the outbreak a Public Health Emergency of International Concern (PHEIC). In February 2020, the disease caused by this novel coronavirus was officially named Coronavirus Disease 2019 (COVID-19), and the International Committee on Taxonomy of Viruses designated the virus as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Clinical manifestations of COVID-19 range from asymptomatic infection to severe illness. Common symptoms include fever, cough, sore throat, runny nose, nasal congestion, fatigue, myalgia, and loss of taste or smell. Symptoms may vary throughout the course of the illness. Most patients recover within several days to weeks; however, some cases may deteriorate rapidly and require close monitoring. Older adults, individuals with disabilities, immunocompromised persons, and those with underlying medical conditions are at increased risk of severe complications and death.

Since its emergence in late 2019, SARS-CoV-2 has continued to evolve, leading to the appearance of multiple variants that have influenced disease transmission and epidemiological trends. With the development of population immunity and changes in viral characteristics, the epidemiological pattern of COVID-19 has gradually shifted toward seasonal circulation, predominantly causing mild cases. Nevertheless, the disease remains transmissible and can still result in severe illness and death. To enhance disease surveillance and monitor severe cases, Taiwan designated COVID-19 as a Category V notifiable disease on January 15, 2020, and reclassified it as a Category IV notifiable disease on May 1, 2023. Starting September 1, 2024, the disease name was changed to “Severe Complicated COVID-19.”

Epidemiology

COVID-19 is primarily transmitted through respiratory droplets and secretions produced when an infected person coughs, sneezes, talks, or breathes. Transmission can also occur through close contact or in poorly ventilated environments. Individuals infected with SARS-CoV-2 may be contagious regardless of whether they exhibit symptoms. The incubation period for SARS-CoV-2 infection ranges from approximately 2 to 14 days. Older adults, individuals with chronic medical conditions, and immunocompromised persons are at higher risk of developing severe illness. As the virus continues to evolve, the epidemiological pattern of COVID-19 has gradually shifted toward periodic circulation, resembling other common respiratory illnesses such as the common cold, influenza, and pneumonia.

Prevention

1. Vaccination
 

(1) COVID-19 vaccination enhances immune protection and reduces the risk of hospitalization, severe complications, and death following infection.

(2) As vaccine-induced immunity may decrease over time, the public is advised to complete recommended vaccine doses in accordance with the latest recommendations issued by the Advisory Committee on Immunization Practices (ACIP) under the Ministry of Health and Welfare.
 

2. Health Education and Preventive Measures

To prevent SARS-CoV-2 infection, the public should avoid direct contact with secretions from suspected or confirmed COVID-19 cases and take appropriate precautions against droplet transmission. Recommended preventive measures include:
 

■Following the latest COVID-19 prevention and control policies announced by the Taiwan Centers for Disease Control (Taiwan CDC);

■Maintaining good hand hygiene, especially before meals and after using the restroom, and avoiding touching the eyes, nose, and mouth with unclean hands;

■Avoiding crowded or poorly ventilated public places. Maintaining social distancing (1 meter outdoors and 1.5 meters indoors) or wearing a mask is recommended when appropriate;

■Wearing a mask and practicing proper respiratory etiquette while using public transportation when experiencing respiratory symptoms;

■Staying home from work or school and resting when feeling unwell. Individuals with warning signs or those at high risk for severe illness who test positive by rapid test should seek medical attention promptly;

■Following the national COVID-19 vaccination policy and receiving recommended vaccine doses on schedule.

Treatment

1. Taiwan currently maintains a stockpile of both injectable and oral antiviral medications for COVID-19 treatment. For recommendations regarding administration, eligible populations, dosage, and other treatment considerations, please refer to the relevant documents at https://reurl.cc/7EQO41.

2. To reduce the risk of severe illness following SARS-CoV-2 infection, individuals aged 65 years and older, pregnant women, postpartum women, and persons with chronic diseases, immunocompromising conditions, or immunodeficiency (as defined in the “Clinical Management Guidelines for SARS-CoV-2 Infection” issued by Taiwan CDC) are advised to seek medical attention promptly after testing positive by rapid test. Physicians may evaluate whether these individuals are eligible for oral antiviral treatment for COVID-19.

FAQs

1. What is COVID-19 and how was it discovered?

On January 30, 2020, the World Health Organization (WHO) declared the outbreak a Public Health Emergency of International Concern (PHEIC). On February 11, 2020, the disease caused by the novel coronavirus was officially named Coronavirus Disease 2019 (COVID-19), while the International Committee on Taxonomy of Viruses designated the virus as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).

2. How can I prevent COVID-19 infection?

To prevent SARS-CoV-2 infection, individuals should avoid direct contact with secretions from suspected or confirmed COVID-19 cases and take precautions against droplet transmission. Recommended preventive measures include:
 

■Following the latest disease prevention and control information announced by Taiwan CDC;

■Maintaining good hand hygiene, especially before meals and after using the restroom, and avoiding touching the eyes, nose, and mouth with unclean hands;

■Avoiding crowded or poorly ventilated public places. Maintaining social distancing (1 meter outdoors and 1.5 meters indoors) or wearing a mask is recommended when appropriate;

■Wearing a mask and following respiratory hygiene measures when using public transportation;
■Staying home from work or school and resting when feeling unwell. Individuals with warning signs or those at high risk for severe illness who test positive by rapid test should seek medical attention promptly;

■Following the latest COVID-19 vaccination policy and receiving recommended vaccine doses on schedule.

3. What are the warning signs of severe COVID-19 illness?

Warning signs of severe COVID-19 illness include tachycardia (heart rate >100 beats/minute) in the absence of fever (body temperature <38°C), shortness of breath or difficulty breathing (respiratory rate >30 breaths/minute or oxygen saturation ≤94%), persistent chest pain or chest tightness, altered consciousness, cyanosis of the skin, lips, or nail beds, inability to eat, drink, or take medications, significantly reduced urine output or no urination within the past 24 hours, and systolic blood pressure <90 mmHg. Individuals experiencing these warning signs should seek medical attention immediately.