How to COVID-19 Coronavirus enter the body and affect the respiratory system?

COVID-19 Coronavirus – is the name of panic for people around the world in recent times.

The new family member of the Coronavirus is spreading rapidly to people all over the world. The most vicious part of this virus is that the virus does not behave like any other virus, and it does not care about cold or warm weather at all. Viciousness part of the virus is causing painful death to the human by attacking its respiratory system. If we can know how this virus enters the human body and attacks the respiratory system, it will be easier to defeat the virus.

1. The nature, structure, and characteristics of COVID-19 Coronavirus

The full name of this virus is Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The other two family members of this virus are SARS (Severe Acute Respiratory Syndrome Coronavirus-SARS-CoV) and MERS (Middle East Respiratory Syndrome – MERS-CoV).

The Coronavirus is an enveloped virus and it’s coated with an oily coat, which is known as “Lipid bilayer” studded with proteins that stick out like spikes of a crown. That’s why the virus is named as Coronavirus; Corona means Crown in the Latin language.

Fatty plaque and spikes parts are made of protein or amino acid. And soap or alcohol is alkali or alkaline. In the presence of water, the amino acids (Weak acid) break down or thaw by reacting with alkali or alkaline. So, the virus is wrecked.

Acid + Alkali → Salt + Water, here acid became neutralized.

NH₃-COOH (Amino acid) + OH⁺ (Alkaline) → NH₃– R-COOH (Neutralized compound) + H₂O (Water).

That’s why the World Health Organization (WHO) recommends that washing hands thoroughly with soap or alcohol.

Researches on other coated viruses have shown that the oily coating of the virus becomes sensitive to heat, and it will destroy, which means it can’t survive for long. The oiled coats become hard as rubber in colder environments, as a result of which, the oily coat can protect the virus from escaping the body, that means they can live longer.

Most coated viruses show strong seasonal effects. However, many people believe that the virus is not behaving that way. The virus’s behavior may not be apparent until one more winter has passed.

COVID-19 Coronavirus cases can survive on different objects from time to time. The following is a list of studies on how long a virus can survive when exposed to different objects:

2. How the COVID-19 Coronavirus enters the human body

Disease organisms and toxins enter into the human body through the mouth cavity, nose, eyes, hair follicles, and injection syringes. However, it has found from research that COVID-19 Coronavirus 2020 is entering the human body through the mouth and nose. In some cases, it observed that it could enter through eyes.

The virus circulates in the form of tiny droplets in the air through an affected person’s cough, sneezing, and first floats in the air. After that, it slowly falls on the ground, the floor, any solid object. Apart from this, it can spread by the affected person’s cough, which he throws carelessly anywhere, or when anyone touches the mouth and nose by coughing or sneezing without using elbow for protection, he can also spread the virus through his cuff and abscess.

If the infected person does not use tissue or cloth or elbow to cover the face during sneezing, coughing, and someone is staying within 6 feet of his or her position. Then the free viruses in the air can enter into the healthy body when breathing through mouth or nose. Some scientists say a healthy person stays apart from 3 feet from the affected person during his or her coughing, sneezing; the healthy person only can affect. It may depend on the wind flow and its direction towards the healthy person staying from the affected person.

3.    How the COVID-19 Coronavirus enters the human body and how is coronavirus transmitted?

Disease organisms and toxins enter into the human body through the mouth cavity, nose, eyes, hair follicles, and injection syringes.  However, it has been found from research that COVID-19 Coronavirus is entering the human body through the mouth and nose. In some cases, it observed that it can enter through eyes.

The virus circulates in the form of tiny droplets in the air through an affected person’s cough, sneezing, and first floats in the air. After that, it slowly falls down on the ground, the floor, any solid object. Apart from this, it can be spread by the affected person’s cough which he throws carelessly anywhere, or when anyone touches the mouth and nose by coughing or sneezing without using elbow for protection, he can also spread the virus through his cuff and abscess.

 If the infected person does not use tissue or cloth or elbow to cover the face during sneezing, coughing and someone is staying within 6 feet of his or her position and then the floating viruses in the air can enter into the healthy body’s when breathing through mouth or nose. Some scientists say a healthy person stays apart from 3 feet from the affected person during his or her coughing, sneezing, the healthy person only can affect. Actually, it may depend on the wind flow and its direction towards the healthy person staying from the affected person.

Recently a Japanese researcher used a microlens camera to show that an infected person is continuously spreading the virus in the air, not just sneezing, but also by coughing, talking, and breathing. For this reason, it is necessary to use a mask always.

The Japanese Reacher’s research video is given below:

In the same way, if the cloth, tissue, or elbows are not being used during the coughing, it can fall on to another object. If the used clothes, scarfs, tissues during the coughing or sneezing of the infected person, are not adequately keeping into the closed dustbin. It’s were thrown away without being unconstrained and using the hands instead of the elbow. Without appropriately washing touches, other people, objects, especially door handles /locks, callings bells or lift switches, stair handles, etc., coronavirus are transmitted to those objects, and when an unaffected person touches those viruses are transferred to his or her hands. Then he or she touches his or her or others’ mouths, nose or eyes, or any other object the viruses also enter his or her or the corresponding person’s body or transferred to others.

Attacking the respiratory system or lungs of the human body (mammals) is the main target of the Corona Virus. The virus enters into the body through the nose, mouth, and eyes of other mammals, including humans, to attack the respiratory system. And it stops the process of breathing by the cessation of descent at that point, and gradually mammals, including humans, are hastening to death.

The respiratory system of all mammals, including humans, are like upside-down trees. For a simple description, only humans are discussed in this topic, except for other mammals.

The virus, bacterial pathogens, toxins, dust, etc. that enter into our bodies with different foodstuffs and during our breathing -it is called “Foreign Materials” in medical science, and Viruses, bacteria, fungus, parasites, etc. are called as pathogens.

The pathogens can insinuate into our mouths, nose, eyes so that the next step can destroy them, that’s why our creator sets different defense response system in our bodies. Here we will discuss the only COVID-19 coronavirus instead of other pathogens for convenience of the topic.

3. Respiratory structure, Activities, and Invasion of dust particles and pathogens

The virus, bacterial pathogens, toxins, dust, etc. that enter into our bodies with different foodstuffs and during our breathing -it is called “Foreign Materials” in medical science, and Viruses, bacteria, fungus, parasites, etc. are called as pathogens.

The pathogens can insinuate into our mouths, nose, eyes so that the next step can destroy them, that’s why our creator sets different defense response system in our bodies. Here we will discuss the only COVID-19 coronavirus instead of other pathogens for convenience of the topic.

How COVID-19 Coronavirus infects the respiratory system of the human body and how does the immune system of the body can fight over a certain period and bring about well-being or even – to know it. Before, we need to know the recognizable idea of our respiratory systems, its structures, its activities, and how our bodies are affected by dust and pathogens.

Most of the mammals including humans have 3 parts of the respiratory tree/ track:

1. Upper part: nose and nasal passages, paranasal sinuses, and throat or pharynx
2. Respiratory air wages part: voice box or larynx, throttle or Trachea, bronchi, and bronchioles.
3. Lungs: Respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.

An adult person inhales 13000 liters of air in a day, and the same amounts exhale.

There are three main processes of defense against the invasion of foreign agents: Filtration, Inactivation, and Removal. During the breathing, Viruses, Bacteria, particulate matters, etc.

foreign materials also enter through the nose, upper throat into the human body with air. And foreign substances also can enter the forehead cavity when it contracts with eyes. Air that drawn in through the nose and upper throat and eyes is warmed and moistened as it moves to the lungs.

The particulate matter becomes moist as soon as it enters the nose. Large particles filtered through the nose hair at the entrance of the nose and during the nasal sweep these large particles of dust accumulate with the nose hair or when the nozzle is rinsed with water while washing

Large particulate matter and disease stick to the throat for a long time.  When the foreign materials, including pathogens, enter through throat become moist and warm, and that’s why it feels like something is stuck in the throat, if such feeling arises, they may try to clear throat by a cough or sneeze or throwing spit.

Especially for Muslims, it is the practice of performing nasal cleansing and lower part of the throat with water three times in the preparation of performing Wadu and bathing before prayers.

There may be rules for becoming pure before worship in other religions. As a result, the pathogens and dust trapped in the hair follicles of the nose easily cleansed.

Whether there are many questions about the cold is harmful to the human body or not. Its answer is, “YES.” It shows the respiratory chemosensitivity, and it disrupts blood flow to the heart and lungs of the human body (Pulmonary Vascular Disease).

The internal temperature of the human body is usually 30 degrees centigrade.  But, when any matter (maybe food or drinks) or air enter into the human body below this temperature that causes and decreases the body cell’s cold, then the body cells become silent and cannot function much.

Whereas Ingesting warm water or food or inhaling warm air, internal cells of the body become stimulated and activated, and metabolism of the body also highly active with the destruction of disease germs. 

Metabolism is the chemical reactions inside the animal body by which food are digests and converts into energy, mixed with blood and transported to the cells via blood, and metabolism continues inside the cells, fighting against the environmental toxicant (Xenobiotics), removing unnecessary and waste products from the body.

The Xenobiotics (poisonous substances) metabolism occurs at the entry points of the body, such as at the skin, lungs, liver, kidney, and gastrointestinal tract, where the liver plays a central role.

Metabolism is the sum of all the chemical reactions inside the body by which we survive, strengthen, and grow the body structure, generate energy, and it is the process of developing the immune system. That is why warm food, drinks should be taken instead of cold food.

And in specialist opinion is the take warm water after half an hour of meals, they advise to drink warm water to the patients with sickness, especially those with respiratory diseases, drinking warm water can bring relief in case of illness also.

There is widespread in social media that by repeatedly drinking warm drinks and by inhaling warm water vapor through the nose and mouth, the patient released from the virus, which means it found negative in the next test.

One of the reasons may be since the coronavirus enters the human body through the mouth, nose, or eyes, it remains in the humid and warm state for some time on the throat, including on the throat for an average of 7 days. And the outer surface of the virus is formed by an acid coating so that the virus destroyed when the upper layer acid of coronavirus dissolved in warm drinks or hot steam.

And warm drinks and steam activated the innate human cells in the body. They developed the metabolism inside the body, which can benefit by providing additional strength in the fight against the virus.

Many peoples say that warm water with honey and lemon juice drinks are perfect for health, especially for respiratory disease suffering patient. Raw honey that is unprocessed honey is best for health.

According to the United States Department of Agriculture (USDA), in a tablespoon of raw honey contains about 64 calories and 17 g of carbs. The main benefit of honey is its antioxidant, anti–bacterial, and anti–viral. So, it is very effective against bacteria and viruses.

And antioxidants that can help to strengthen our immune system prevent infections and keep the heart–healthy.

Besides, honey is a good source of vitamin–K, D, and E, and this complex is known as beta–carotene. Honey also gives relief from nasal congestion, respiratory problems (DRHealthBenefits.com). Antioxidants are also capable of neutralizing free radicals’ molecules that are a threat to human health anytime (HEALTHYSAB).

Lemon Juice is also rich in anti–oxidant. Lemon is the most abundant natural source of vitamin–C, which is the utmost importance for our body. A deficiency vitamin–C levels are known to cause a lot of health disorders. Vitamin–C protects our immune system. It protects the epithelial cells by which our skin, outer, and inner structure of our body organs form by creating a membrane between the epithelial cells and the bacteria or viruses (HEALTHYSAB and PubMed).

So, Lemon and honey in warm water serve as an energy booster. It poses a threat to the mucus present in our throat and sighs relief. The benefits of honey and lemon juice in warm water are:

• (a) strengthen our Immune System,
• (b) Reduce Inflammation which connected with the development of many chronic diseases,
• (c) help cure a sore throat and cough,
• (d) boost our digestive health,
• (e) help treat kidney stones,
• (f) can lower our risk of heart disease,
• (g) helps lower blood pressure,
• (h) can help lower bad cholesterol (LDL) and increase good cholesterol (HDL),
• (i) Can Help to detox,
• (j) Help Lose to body Weight,
• (k) enhance metabolism, etc. (Sources: Healthy and Natural World).

Germs of diseases and particulate matter can enter the respiratory tract or trachea after moistening and warm in the throat. There are billions of tiny hair–like fibers called cilia staying in the trachea. They act like a broom and move up and down at a rate of 13,000 beats per minute.

The human body has three lobes in the right lung and two lobes in the left lung. The trachea divides into the main bronchi, which goes to the right and left lungs. The bronchi divide into thinner tubes, called bronchioles. Many tiny air sacs called alveoli located at the ends of the bronchioles, where the exchange of gases takes place.  A healthy adult has about 400 million alveoli in his lungs.

In the alveoli, inhalation of oxygen (O2) and exhalation of carbon dioxide (CO2) produced in the body cells take place. A thin sheet of moving blood move over the alveoli, during the flow of thin layers of blood, the blood inhales oxygen from the air entering the lungs and exhales carbon dioxide.Due to continuous contraction of bronchioles and alveoli and constant motion of the cilia on top to bottom, oxygen-rich air enters through the nose, mouth to throat, trachea, bronchi, bronchioles, and alveoli. And carbon dioxide produced by the biological action of the body’s cells is purified by the blood and evacuated into the alveoli of the lungs. Same way, through the opposite airflow of mouth by the nose, exhaled into the air by nose and mouth. This system is the breathing that runs in the human body continuously.

It may be mention that two types of blood vessels carry blood inside the body. The blood vessels that carry contaminated blood (CO2-carrying blood) from different cells in the body to the lungs through the heart are called veins. And those carriage oxygen-rich blood from the lungs to various cells in the body are called Artery.

Red cells of blood carry oxygen from the lungs, and it brings carbon dioxide to the lungs. The heart controls the flow of contaminated blood from different organs to the lungs and from the lungs to different parts of the body through the periodic contraction and expansion of the four valves (Every time the expansion of 2 valves and contraction of 2 valves run periodically) at heart. The heart acts as a pump to carry blood to the body.

The response of the tracheobronchial area to large particulates is a contraction of the muscles, causing the lumen of bronchi to be narrowed. This results in the removal of solid particulate matter with a diameter above 5 mm and permits less of the particulate matter to enter the lower portion of bronchial tubes. The mucus that is secreted moistens the particulates as they accumulate, which are then removed through the cough reflex. Cilia (hair-like structure) beat rhythmically back and forth in the air passage, billions of cilia function like a broom to sweep noxious foreign agents out of the system.

But less than 5 millimeters in size dust particles, toxic substances, enters into bronchial and bronchioles. The air accumulates for some time before the entering of the alveoli from the bronchioles. At the time of contractions and propagation of bronchial and bronchioles, it’s coughing of the micrometer size those removed by coughing, mucous.

Particulate matter that reaches the alveoli and deposit is usually 1 micron or less in diameter. There are four types of cells in the alveoli: alveolar epithelial cells, endothelial cells, large alveolar cells, and alveolar macrophages. Functions of them are as follows:

• 1. alveolar epithelial cells: responsible for the exchange of CO2 and O2
• 2. Endothelial cells endowed with various protective properties.
• 3. Large alveolar cells and alveolar macrophages carry out oxidative and synthetic processes that defend the lungs against invading organic and inorganic materials

Less than 1 micrometers particles can breach the alveoli and accumulate in them. Toxins can be absorbed quickly into the bloodstream. And some of the disease germs mix with the blood and enter the body, and it causes infection in alveoli; for that reason, the alveoli swell or become too large to shrink; in this case, a human can take breathe, but cannot exhale it.

As a result, the alveoli filled with air and start having difficulty breathing and feel severe pain in the chest and back. Because of the shortness of breathing, the flow of oxygen decreases inside the body. And in the absence of oxygen, the organs become exhausted or inactive. At this stage, the heart can be stopped, the brain and kidneys damaged, and humans can die.

In this situation, Separate pure oxygen attaches to the lungs for providing adequate oxygen to the patient’s body, or artificial respiration (Ventilator) is to add for the inactive lungs. Mainly, the Ventilator acts as an artificial lung, tries to repair the respiratory system of the patient by applying the medication.

Once a virus or bacteria enters into the human body, it tried to infect the human cells from its entering point to the alveoli and also the blood cells in the trachea.

For some reason, if the polluted air, excessive dust, dust particles, or smoke enters our trachea, then need to cough repeatedly for the purification and contraction of the respiratory tract at different stages and gradually the resilience of our respiratory contractions and expansion tends to decline.

The disease begins to infect various organs from the nose, throat, to the alveoli when they enter the respiratory system. And spread there (Unless the immunity-strength can fight and cannot defeat them), and it spreads to the walls of the limbs to thin and expand those, it destroys them by swelling.

At this stage, people can breathe, but it is not in a healthy way, then he or she has to cough loudly to get those out and has to breathe under pressure even need to breathe fast and loudly. Primarily, this problem associated with bronchi and bronchioles is called chronic bronchitis/ Emphysema (Respiratory disease).

Usually, Bronchitis could not be able to air out naturally or incapable; it occurs the expansion of the respiratory tract from the tip of the nose to the bronchioles. Shortness of breath can cause by severe Bronchitis. It may also cause allergies. If in the initial state, the clean environment is not found or stop smoking and if appropriate treatment is not received- it became more complicated gradually, and it can be converting into a complex situation in the middle of life.

According to the WORLDOMETER till 04/05/2020, the death rate of COVID-19 coronavirus 2020 patients as per age is given below (Death Rate = (number of deaths/number of cases) = probability of dying if infected by the virus (%):

4. How the human body infects by the COVID-19 Corona Virus

Dr. Martin S. Hirsch, a senior physician in the Infectious Diseases Services at Massachusetts General Hospital, said: “There are many more things to know about the COVID-19 virus, but experts suspect the virus may act similarly to SARS-CoV from 13 years ago.”

The COVID-19 virus begins to attack as soon as it enters the human body.

Hirsch says the coronavirus shows its symptoms of infection within 14 days from the time it enters the human body.”

It is better to mention that a virus is not a complete cell as it has no nucleus. Hence these are called “Parasite,” which means virus can’t grow independently; instead, it requires other’s bodies to develop. So, a virus is not capable of producing another virus itself. They enter the nucleus of human cells and hijack the cell’s genetic material forcing it to make more viruses by a process called “Replication.”

There are three types of blood cells circulating in the bloodstream, called Red Blood Cell, White Blood Cell, and Platelet. White blood cells are also called lymphocytes, and it serves as the main components of our immune system. They are the soldiers that fight against different pathogens entering our bodies. There is a particular type of protein called antigen outside of the shape of a pathogen (e.g., Virus or Bactria) that attack the immune system of the human body. These antigens in coronavirus extend around its body to the outer edges like a crown. White blood cells produce antibodies against the antigens of different pathogens and destroy them.

As soon as white blood cells attacked them when they received the signals from the immune system, and the immune system gives energy to the cells to kill them. There are billions of white cells in human blood, But the problem is that all white blood cells could not produce the same antibodies. Therefore, if the infected person’s immune system is high, it destroys the viruses (bacteria) in the body. It respires from the body through the blood to the kidneys.

People who have low immunity, the white cells of the blood in their bodies cannot fight for a long, and the virus endures to create numerous its replicates, using the genetic materials of the human cells. And gradually, it infects all parts of the respiratory system to the lungs, therefore, it causes infection, and a person who has this condition is called Corona infected patient.

COVID-19 Coronavirus enters the human body through the nose, mouth, or eyes and starts infecting the body cells from the direction of the respiratory system immediately. They attack the epithelial cells of the human body first. The Body skin, the inner and outer structure of each organ such as the oral cavity, the nasal passage, the throat, the alveoli, the Trachea, the outside and inside of the respiratory passage, etc., are made up of epithelial cells. These cells attach in a linear manner that protects an organ from being in and out.

The protein named antigens of coronavirus attack the proteins of epithelial cells and tries to enter into the cell. When the white cells are not able to recover or during the fighting, the virus starts to create the infectious virus in the human cell until the body cell is being killed.

The coronavirus infects the upper part of the respiratory system, such as the nose, mouth, eyes, throat, trachea, and bronchioles in the first phase. At the same time, people have mild symptoms like sore throat, forehead pain, dry cough, fever, shortness of breath – dry cough, muscle pain, body pain, etc.

Usually, who have a robust immune response, they can defeat the viruses that enter their bodies in the upper part of the respiratory system, and they cure within 5-6 days.

Usually, the immune system of children is the most powerful and its remnants for up to 40 years unless it is affected by any other disease, especially respiratory disease. Or falls to another disease before the onset of the infection of COVID-19 and if women are becoming pregnant.

Pregnant mothers have low immunity; Because the immune system is in a critical state of formation of another body inside their bodies, the expectant mothers are already infected with other diseases, including prenatal diabetes, as they are in stress.

If it extends from the upper part of the respiratory system to the lower part, it reaches a very catastrophic stage of an infected person.

Dr. Pragya Dhaubhadel and Dr. Amit Munshi Sharma are working as the infectious disease specialists at Geisinger (Central, Southwestern, Pennsylvania, and New Jersey healthcare, United States).  Who said that “Some people are informed that they are suffering for stomach infection, for example, vomiting and diarrhea. However, such cases are sporadic in cases of coronavirus infection”.

Percentage of COVID-19 infected by mild or moderate, severe and critical stage of age is shown in below:

It is notable from the above table, 13.80% occurrence of severe infection and 6.1% of the critical condition occurs, in that case, the coronavirus enters the lower part of the respiratory system through the airways/ trachea. And this is the place where viruses consider to be a suitable place for overgrowing.

Dr. Hirsch says that “lungs are the main target of the coronavirus.”

When the number of viruses is overgrowing, it enters into the airways of bronchi and bronchioles, and then enter into the alveolus. At that time its attack the bronchial cells and the epithelial cells of the alveoli of lungs. And the epithelial cells are infected, destroyed, and the elasticity of cells became lost due to swelling or spread in each location. So that contraction of the respiratory area is obstructed and is not able to take breathe or exhale effectively. This condition for the patient is called a critical moment or Pneumonia.

Pneumonia is a small cough with shortness of breath and coughing, and it infected the tiny air sacs or alveoli in the lungs.

They are affected by Pneumonia that the virus infects the small air sacs in the lungs or alveoli. During this period, the viruses destroy the epithelial cells in the walls of the alveoli, and it causes rapid reproduction. As a consequence, the wall of the alveoli becomes thinner. And because of that, it can lose their elasticity, and it may swell and no longer be compressed, thus gradually, the respiratory activity will be collapsed. Even at this stage, the immune system sends white blood cells to fight, and it adds energy to the living cells for fighting. At this stage, the patients are supported by pure oxygen (100%) from outside the body. Generally, the air we inhale contains only about 21% oxygen.

After entering the viruses into the alveoli, a portion of it mix with bloodstream and is destroying blood hemoglobin, which causes disrupting the oxygens carry in human blood. And the viruses also infect the human heart, causing myocarditis (Inflammation of the heart’s muscle layer).

It is a peculiar war between human cells and viruses.

Hirsch said that ” The life and death of an infected person will depend on this war, good results will come to that means, he or she will be free from the disease if his or her immune system wins in the war or he will die if the virus will defeat his immune system.”

If the immune system loses its ability to fight, the wall of the alveoli becomes thinner, and the elasticity is lost completely, Then the blood circulation also being stopped entirely, and the exchange of oxygen and carbon dioxide to the lung also blocked. This condition appearing a patient is called Acute Respiratory Distress Syndrome (ARDS).

Very few patients with acute respiratory distress syndrome (ARDS) can return to pulmonary function, and then, the artificial respirator (ventilator) is attached to their body to provide lung function outside the body.

Due to a lack of oxygen supply into blood, the function of various organs of the body like heart,  kidneys,  brains are being stopped.

If most of the lungs are damaged, the respiratory failure of the breathing apparatus causes other parts of the body to lose its function, and then the patient dies (organ failure and death).

Medicine Specialist Dr. R. Viscidi of John Hopkins University emphasizes that ” Usually people of age above 70 years and whose has low immunity, those infected people are more vulnerable to death. Among others, peoples with pulmonary diseases, chronic diseases like asthma and other respiratory disorders, cancer patients who have gone through chemotherapy treatment.

Therefore, the adult/aged people, who are already suffering from heart and respiratory diseases and cancer patients who have been given chemotherapy, and pregnant women have to move very carefully and maintain social distance.

Ref:

1. Book: Environmental Toxicology (Second Edition) –By Ming–Hu Yu
2. Topic: What does the coronavirus do to your body? Everything to know about the infection process By Javier Zarracina, and Adrianna Rodriguez, USA TODAY, Updated 11:00 p.m. BST Mar. 16, 2020.
3. WIKIPEDIA, COre77, WebMD, PubMed Axis, and Allies, www.biology–pages.info, antranik.org, Nature Reviews Immunology, and HEALTHYSAB, DRHealtBenefits.com
4. Topic: Why a coronavirus vaccine is more than a year away, despite medical researchers’ progress by George Petras, Ramon Padilla, and Veronica Bravo, USA TODAY Updated 1:39 p.m. PDT Mar. 11, 2020.