[Kim Byungmin's Science Village] The Attack of COVID-19... When Will a Vaccine to Prevent Infection Be Available?

The Discovery of Penicillin's 'Serendipity'... That Chance Was an Inevitability Made by Effort
New Drug Development Involves Many Stages... Requires Massive Investment of Money and Time
Shortsighted Attitude Blinded by Capital... Could Become an 'Enemy' Threatening Human Survival

Byungmin Kim, Science Writer

On the 20th of last month, shortly after the first confirmed case of the novel coronavirus infection (COVID-19) was reported in South Korea, the emergence of a super-spreader became a hot topic in the media and on social networking services (SNS), with the confirmed patient's movement paths drawing significant attention. The patient's movements, reminiscent of the legendary Hong Gil-dong, were revealed through epidemiological investigations, leading to the public exposure of private lives and the spread of exaggerated rumors. While privacy should be protected, secrecy could no longer be maintained due to the unavoidable measures taken to prevent further spread. I also thought that those who might be implicated in the infection route could fear the humiliation of being completely exposed. A friend working at a pharmaceutical company joked that the sales of male erectile dysfunction treatments might decline as adults' secret bedrooms could be exposed.

Humanity has developed new drugs to overcome diseases. An interesting fact is that the drug most commonly associated with male erectile dysfunction treatment was not originally created to cure that condition but was a serendipitous result derived from immune-related research.

The human brain does not recognize the entry of pathogens or viruses into the body. However, the biological process of immunity does. The immune system is the mechanism that appropriately defends against pathogen invasion.

Our body, like a medieval castle, has multiple layers of defense and offensive weapons. Just as high castle walls and firmly closed gates limit external access, our body has a primary defense line before the immune system, like a fortress wall. The skin blocks bacterial invasion with keratin, which consists of dead skin cells, and lipids secreted from dying granular cell layers. This is why burn patients are vulnerable to infections, and scrubbing the skin while bathing is not beneficial for defense.

Moreover, a person inhales about 500cc of air containing nearly 10,000 bacteria with each breath. Viruses are no exception. Bacteria, which are not as tenacious as viruses, are trapped in mucus in the airway just before reaching the lungs and expelled by cilia. Phlegm and coughing are their spoils.

Mucus present not only in the respiratory tract but also in the eyes, nose, and reproductive organs is not just a simple secretion but a chemical weapon containing antimicrobial proteins. Even blocked ears clean themselves with earwax, a mixture of lipids and antimicrobial proteins. Earwax is not a dirty substance that must be deliberately removed.

The full-fledged immune system activates when the primary defense gate is breached. Killer cells of the secondary defense line distinguish bacteria and viruses by specific molecular patterns different from human cells. It is fortunate for humans that microorganisms, which must replicate and proliferate dichotomously, cannot lose these characteristics.

Neutrophils, representative killer cells, pour about 200 million daily from the bone marrow into the bloodstream to capture infections. Once captured, they kill pathogens. Macrophages, present in most body tissues, engulf bacteria as their name suggests.

Killer cells, also called white blood cells, leave evidence of having dealt with pathogens in the form of pus, a residue. However, despite their name, their operation is not sophisticated. Neutrophils spread nets in the battle area, releasing toxic chemicals to decompose trapped bacteria. Consequently, normal tissues also suffer significant damage. This is why nearly 50 million people died during the 1918 Spanish flu pandemic.

Besides these rough killer cells, there are natural killer cells. They interrogate infected cells and, if suspicious, perforate them. They secrete enzymes that cause the cells to self-destruct, acting as special agents.

When the fortress gate is breached in battle, the cells shout the enemy's infiltration location to their allies so that troops can move to the breached area and fight. Since cells cannot speak, they release chemical messengers that act as heralds. These chemical messengers cause acute inflammation in body tissues, attracting killer cells. Feeling pain from inflammation during infection means the immune system is functioning properly.

One of the representative chemical messengers used by the body is nitric oxide. Nitric oxide is produced by vascular endothelial cells or macrophages in tissues. Nitric oxide spreading through blood vessels in the battle area dilates the vessels. When blood vessels widen, blood flow increases, allowing a rapid increase in white blood cells. Pharmaceutical companies searching for angina treatments study drugs that increase nitric oxide production in the cardiovascular system based on discoveries from the body's immune response.

New drug development involves many stages, requiring time and cost. Among them, clinical trials to verify that the drug's effects and side effects are sufficiently separated to distinguish between medicine and poison are the most important.

Unfortunately, clinical trials for angina treatments were not successful from the start and were halted. However, unexpected side effects were reported from patients participating in the trials. After administering the new drug, unwanted erections occurred. The newly developed drug increased nitric oxide production in the penile tissue, leading to vasodilation. Erectile dysfunction treatments were thus born from this serendipitous process, shaking the pharmaceutical market and exchanging for enormous wealth.

Serendipity in immune-related new drugs is not limited to this. The primary defense mechanism, mucus, contains chemical weapons. Tears, a representative mucus, contain electrolytes like sodium and potassium and over 100 proteins. Among them, the lysozyme enzyme is another key player.

In 1921, Alexander Fleming was researching substances that inhibit bacterial growth by adding various materials to bacterial culture plates. One day, he added mucus secretions from a cold-infected nose to a culture plate. Surprisingly, the mucus stopped bacterial growth. The cause was identified as lysozyme. This enzyme neutralized specific molecular patterns that make up bacterial cell walls. This eventually sparked the discovery of penicillin, the first antibiotic.

However, we cannot rely on such serendipity forever. Humanity only knows the part of the immune iceberg that has surfaced. Viruses, in particular, remain deeply hidden. In fact, viruses and bacteria are both enemies and saviors of humanity. Therefore, scientists advocate symbiotic models where unknown diseases can be overcome by viruses or bacteria. The science of phages, which began in Eastern Europe in the 1950s, is a representative model.

Bacteriophages are viruses that use bacteria as hosts. Unlike antibiotics, a single phage acts only on specific bacteria. Therefore, specific phages must be found for each bacterium. Until then, humanity must rely on antibiotics. Despite criticisms about antibiotic overuse and resistance, it is difficult to maintain current lifestyles with only the basic immune system. Minor wounds treatable with antibiotics today once led to necrosis and death.

Alexander Fleming accidentally discovered penicillin while researching substances that inhibit bacterial growth.

Ultimately, antibiotics should be prescribed only when necessary to delay the emergence of resistant strains as much as possible. Next-generation antibiotics must be developed in response to the emergence of pan-resistant bacteria. However, such new drug development consumes much time. Although science and technology have advanced, unfortunately, the best method remains trying various substances and hoping to find bacterial growth inhibitors, as Fleming did in the past.

Penicillin is a fungus, but most antibiotics are made by exploiting bacteria's self-protection substances. Therefore, scientists still search natural environments where bacteria thrive. This requires time and enormous costs.

Vaccine development is no exception. Developing antibodies against newly emerging giant viruses or repeatedly mutating viruses involves high costs and risks of failure. Consequently, pharmaceutical companies avoid developing new antibiotics and vaccines because it is not economically viable. For over 30 years, pharmaceutical companies have withdrawn from antibiotic development and shifted their focus to new drugs for cancer and heart disease treatments, which can be exchanged directly for wealth.

Fighting bacteria is an unavoidable reality, but pharmaceutical companies, despite knowing this well, turn a blind eye. Vulnerable groups weakened by capital are at risk of having even their rightful access to healthcare ignored and facing medical discrimination.

Short-sighted attitudes blinded by capital may one day shake the entire social ecosystem. Serendipity is not mere chance; it involves countless efforts. What is slowing down those efforts?

Capital has become a power that dominates even human society beyond being a means of storing or exchanging value. Capital is blessed only in market economies. It may not be an invisible hand but an invisible enemy like a virus.

Adjunct Professor, Nano Convergence School, Hallym University

This content was produced with the assistance of AI translation services.