[Kim Jaeho's Life Story]<180> The Neglected Shield Against Infectious Diseases

As the number of infections and deaths from coronavirus disease (COVID-19), which originated in China, rapidly increased and spread not only to neighboring countries such as South Korea, Japan, Hong Kong, and Singapore but also as far as the United States and Europe, fear of this virus has engulfed the entire world. Although the whole world is striving to prevent transmission, the characteristic of being contagious even during the incubation period has caused the spread to worsen over time.

Infectious diseases are illnesses caused by pathogens such as bacteria or viruses entering the body through various routes and causing symptoms like high fever, cough, and difficulty breathing. The best way to prevent infectious diseases is to block the transmission of pathogens, but as seen in the case of COVID-19, it is not easy to completely block highly contagious pathogens.

Vaccination is an effective preventive method, but it often takes a considerable amount of time to develop vaccines, making them unavailable when urgently needed. Especially, viruses mutate easily, making timely development difficult and limiting the ability to develop vaccines for all viruses.

Once infected with an infectious disease, there is no problem if the hospital can provide good treatment, but can hospitals cure all infectious diseases well?

When infected with bacterial infectious diseases, hospitals treat patients with antibiotics. Antibiotics suppress the reproduction of bacteria and kill them, and have been used for a long time to treat bacterial infections. However, due to the overuse of antibiotics, bacteria resistant to antibiotics have increased, revealing limitations. According to the U.S. Centers for Disease Control and Prevention (CDC), about 2.8 million Americans are infected with antibiotic-resistant bacteria annually, and 35,000 die.

Antibiotics are completely ineffective against viral infectious diseases like COVID-19, and there is currently no treatment method that kills viruses. Hospitals isolate patients to prevent transmission to others and can only alleviate symptoms while immune cells fight the virus. Antiviral drugs like Tamiflu can suppress the replication of some viruses but do not kill them, and have side effects such as toxicity to normal cells and the development of viral resistance.

Thus, prevention and treatment methods for infectious diseases have many weaknesses, limiting the ability to prevent or cure any infectious disease.

People tend to think that once pathogens such as bacteria or viruses enter the body, illness is inevitable, but many people around us do not develop symptoms even when pathogens enter their bodies, or recover naturally over time if they do. This is because an excellent shield capable of overcoming any pathogen is prepared inside our bodies.

The skin of our body blocks bacteria and viruses from entering, so no pathogen can enter the body unless it passes through the mouth, nose, wounds, contact with bodily fluids, insect bites, or contaminated medical devices. Even if pathogens manage to enter, they are expelled through nasal mucus, coughing, sneezing, mucus in the respiratory or gastrointestinal tract, vomiting, and diarrhea, and stomach acid kills them in the stomach.

Bacteria and viruses that survive after penetrating these multiple layers of defense are detected and killed by immune cells called white blood cells. Even if bacteria or viruses manage to break through these shields and cause illness, the immune cells continue attacking until they eliminate the pathogens. When catching a cold or flu, people often think that medicine cures them, but no medicine kills viruses; the illness only heals when immune cells kill all the viruses.

Unfortunately, many people around us do not understand the importance of the immune system and suffer from various infectious diseases due to weakened immune function caused by poor lifestyle habits. COVID-19 has confirmed the importance of the immune system, which is the shield against infectious diseases that has been neglected. Elderly people with weak immunity and those suffering from diseases such as cardiovascular disease, diabetes, chronic respiratory disease, and hypertension show much higher mortality rates.

The immune system exists in the form of genes from birth until death, so it is important to maintain its function at the highest level. If immunity temporarily weakens and one contracts an infectious disease, it is crucial to remember that restoring immunity is the shortcut to recovery, and one must do their best to restore immunity (see Life Story episode 68). Even with hospital assistance, restoring immunity is the patient's responsibility.

Jaeho Kim, Independent Researcher