What Doctors Know About Coronavirus COVID-19 by AudioLearn

What Doctors Know About Coronavirus COVID-19

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COVID-19 in Special Populations .............................................................. 96 Things to Remember from this Section ....................................................................... 100 How will a COVID-19 Vaccine get Created and What is our Future with this Virus? ............................................................................................... 101 How Vaccines are Made ............................................................................................... 103 Developing a Vaccine from Scratch ............................................................................. 106 Creating the COVID-19 Vaccine ...................................................................................110 Things to Remember from this Section ........................................................................ 115 Preparing for COVID-19 in your Community over the Long-term ............. 116 Things to Remember from this Section ........................................................................ 121 Facts and Myths on COVID-19 ................................................................. 122 Things to Remember from this Section ....................................................................... 128 Research Efforts on COVID-19 in the World ............................................ 129 Things to Remember from this Section ....................................................................... 132 Summary ................................................................................................ 133

PREFACE Not too long ago, only a few people in the world understood more than the basics about coronavirus—mostly because no one really had to know much about it at all. In the blink of an eye, however, everything has changed so that COVID-19, which is a particular strain of coronavirus, is a big part of our everyday lives. Suddenly, this obscure virus is on everyone’s mind and is a reality of life in all parts of the world. How did this infection happen in the first place and what do doctors know about how this virus came to be? Is this something we will always have to face in our lives or is it a transient blip in our experience with human diseases, just as the Ebola virus was once a big viral illness that everyone worried about but has since become much less of a worry today? In this audiobook, we will tell you all we know about the COVID-19 virus and what we can expect as this virus continues to be an issue everyone must personally deal with. You will learn in this audiobook about viral infections in general and how they can affect you in so many ways. Viruses like COVID-19 have been a part of human existence since the dawn of man. In terms of evolution, viruses came into existence on earth as soon as the very simple organisms evolved billions of years ago on this planet. No one knows if viruses existed before simple organisms like bacteria arrived on earth but most researchers suspect they did. The reason why is that viruses are a type of infectious organism that absolutely must have some type of host in order to survive long at all or to make offspring. This is why doctors call viruses infectious particles instead of organisms, because they truly are unique among the different infections we can get. A virus host can be anything, from a simple bacterium that is just a single cell to complex organisms like plants, animals, and humans. Viruses themselves aren’t really considered forms of life at all, which makes them different from forms of life currently recognized. They do not have a cell membrane that surrounds their genetic material and they cannot create offspring by themselves, which is what doctors use to define what is a

living thing and what isn’t. Without a host to help the virus make infectious baby viruses”, viruses would not be able to cause infection or spread in any dangerous way. Viruses like COVID-19 are considered to be perfect parasites. A parasite takes what it can from its host but also relies heavily on the same host for its own survival. As a parasite, the majority of viruses are detrimental to our health and rarely have beneficial potential. Virus particles hijack our cells and are basically selfish infectious pathogens, using our own cellular processes and cellular energy for its own purposes, offering the host nothing in return. COVID-19 is no different from other virus particles that have caused human diseases for millennia. In the next few minutes, we will talk about what this virus is all about but, suffice it to say, without us as humans being excellent hosts for it, COVID-19 simply wouldn’t exist. We are an essential part of its life cycle and are the only way the virus has a chance to spread and take hold in our communities across the world. The more you know about yourself as the host of this virus, the better you will feel about taking charge of COVID-19 rather than letting it take over your life or taking your life altogether. Men and women who hunted and foraged for food in prehistoric times had to deal with all kinds of viral infections in the same way we do today. There were no vaccines at that time, of course, so if a virus was in your community or tribe, the only way to become immune to it would have been to get the infection yourself and survive it. The immune system of early man was probably no different from our immune systems today. You only get the mumps once, for example, and you are immune from getting the mumps again for the rest of your life. The same is true of nearly every strain of virus. The immune system fights it off and remembers the infection so you don’t get it again. But wait? Why do we get a flu shot every year and why does the cold virus come around each winter? It’s because viruses are tricky infectious organisms. They can change their external features ever so slightly over time so that the flu virus of last year is not the same flu virus you might get this year. It’s basically the same type of virus but it changes just a little bit each year so our immune system sees it as something different. It simply doesn’t’t recognize the altered virus anymore. So the immunity to the new viral strain you could have this year just isn’t the same as the immunity you got when you had the

flu or the flu shot last year. As you’ll learn, COVID-19 has the capacity to mutate as well, although no one know when or if it ever will. In most cases, viruses are also very specific to a certain organism or to a certain tissue within a complex plant or animal. This is why we have respiratory viruses, nervous system viruses, and stomach viruses that preferentially infect just a part of our body. A few viruses affect the entire body but most are very limited in what they can do. Even HIV, which is a virus that affects the whole body, really only does so because it infects a certain type of immune cell that, in turn, affects the entire body’s ability to fight off other infectious diseases and cancers. In the same way, there are bacterial viruses, plant viruses, and viruses specific to a certain species of animal. We are exposed to plant viruses all the time but these mean nothing to us and represent no danger to humans because viruses just don’t work that way. If you aren’t a plant, you do not have to worry about a plant virus infecting you. Even viruses your pet dog gets probably will not affect you. Viruses just aren’t all that smart in that sense. Some viruses, however, like COVID-19, are called zoonotic viruses because they actually can pass from different animals to humans. What viruses do have in order to make up for their lack of smartness and overall simplicity is sheer numbers. There are just so many of them in any infection—probably thousands of them in each human cell infected with a given virus at one time. It takes just one virus particle to start the process of an infection and, once the virus takes hold in just one cell of our body, the potential for it to spread to all the cells it can possibly infect is great. In addition, because we’re dealing with such high numbers, the chances of one virus particle changing into a slightly different strain is high. This is why things like the flu and cold viruses just keep coming back. Their sheer numbers simply get around our immune system through ingenious disguise mechanisms. COVID-19 is a novel strain of virus in the coronavirus family. As it turns out, the name COVID-19 means something. Researchers call the family it comes from CoV, which means coronavirus for short. The 19 in the name means it was discovered in 2019. A novel strain is the same thing as saying, new strain”, indicating one that humans haven’t experienced before so they aren’t immune to it.

Novel virus strains like COVID-19 are not much different from the new strain of the flu virus you might get this year. COVID-19 did not come out of the blue. Coronaviruses have actually been around on earth for a long time. What makes COVID-19 important to humans is that something about this virus has fundamentally changed so we as a human race have never been exposed to it in our history (as far as we know anyway). This leaves all 7.5 billion of us on earth a vast new pool of naïve hosts that have become the best of all scenarios from the virus’s perspective. Because virtually no one on earth has the benefit of immunity, the virus technically wins in the infection game, especially in the beginning of its existence among us. With so many uninfected people to choose from, the infection has a chance to spread rapidly up until the point where most people become immune to it or until a good vaccine against it has been made available to us. In this audiobook, you’ll understand what makes COVID19 different from, say, the Ebola virus, which is also something few people are immune to but is far from being as common as COVID-19 will invariably be in the human race. By the time you finish this audiobook, you should feel like you know as much about the COVID-19 virus as the experts do. You will know what this virus is all about, why it has become so prevalent everywhere on earth, how it is spread, and what it looks like if you become infected. You will also learn about why it has become such a huge public health crisis and what is being done to help as many people at risk for this infection as possible. Better yet, you will be better prepared to deal with this virus when it is your turn to get it or when it is in your backyard. The facts and myths about the virus will be explained and the future of this virus on earth will be talked about, even though this might still be speculation and a bit like looking into a crystal ball we don’t completely see clearly yet. You should know, though, that we are learning more about COVID-19 every day as researchers scramble to help people worried about getting this infection and to help people already infected. Like any new health crisis such as the current COVID-19 epidemic, researchers focus on the immediate needs at the moment and only after the dust settles a bit will the whole picture of the natural history of this virus emerge. You are living a part of history that doesn’t come around very often. The more you know about this virus and about viruses in general, the less fear you’ll have and the clearer you will be about the steps you and your loved ones need to take to survive this disease. 4

WHAT IS COVID-19 ANYWAY? Before we talk about COVID-19 specifically, we should talk about viruses in general and how they differ from bacteria, for example. Both of these types of infectious organisms cause disease that can be hard to distinguish from one another by your symptoms alone but are really very different infections. While bacteria are considered to be cellular pathogens”, this is not the case with viruses. Viruses in general are much simpler than bacteria, even though they are no less deadly or less likely to cause serious disease states in humans. Viruses are not cellular at all. They are basically little protein balls filled with genetic material. Some are considered naked protein balls with the outer covering called a capsid. Others have what’s called an envelope around the capsid, which is similar to the lipid or fatty membrane around every cell of your body. The envelope was probably not originally from the virus itself but was an evolutionary remnant picked up when a virus captured a piece of its infected cell’s membrane around it as it left the infected cell to infect other cells. Inside each capsid is a piece of genetic material, which are basically unique instructions every organism has inside each cell or pathogen that tell the cell which proteins to make and allow the cell to function so it can grow and divide to make daughter cells. It’s the genetic material inside the egg and sperm of humans and other species of plants and animals that get passed on from the parent generation to the offspring generation. In all forms of cellular life, the genetic material inside each cell is called DNA or deoxyribonucleic acid. This is an extremely long chain of simpler molecules that can contain different genes. Each gene is its own instruction manual for the making of one protein. It takes thousands of proteins to have even simple cells function, grow, and divide to make daughter cells. Viruses are the only particles that might or might not contain DNA. The DNA inside our cells is considered double-stranded” because it looks like a ladder of two separate but matching strands connected with rungs of molecules that hold the two strands together. In viruses, some will have double-stranded DNA like we do. Others will have single-

stranded DNA or anther related molecule called RNA. RNA or ribonucleic acid is inside our cells too but isn’t the main genetic material. In viruses, the RNA may be the primary genetic material in the particle; it can be single-stranded or double-stranded. These differences are important and change how the different viruses can be treated with antiviral medications. What’s conspicuously absent in virus particles is a complete set of instructions for making new baby viruses”. There is enough genetic material to make the necessary proteins to reconstruct the next generation of virus particles but viruses rarely have the instructions to make the enzymes and other methods of actually replicating or copying the virus itself. This is where you, the host, comes in. You have in your cells just what the virus particle needs and really must have in order to replicate itself. Your cells then become hijacked by the virus particle in order to help the virus become infectious to other cells. Finally, no virus on earth would be at all dangerous if there wasn’t a way for it to pass from person to person. Common ways to transmit a virus include coughing or sneezing, which makes the virus airborne on spit droplets or nasal secretions so it can be inhaled by anyone nearby. This is how many respiratory viruses get from person to person. Other viruses are passed through what’s called the fecal-oral route. This is when the virus is shed in the infected patient’s stool and, if handwashing is insufficient, the virus gets transmitted to food that is prepared by the infected person in order to infect someone else. Hepatitis A is transmitted this way. Still others are only transmitted through sharing blood or body fluids, such as during sex. Hepatitis B, hepatitis C, and HIV are transmitted this way. Finally, viruses can be passed through fomites, which are inanimate objects that have the virus particle on them. This includes countertop surfaces, door handles, and toys a child puts into his mouth and discards for another child to pick up. As you will see, viruses vary significantly in their ability to survive for long on these fomites. Some are tough and resistant so they live for hours or days. Others simply do not survive long at all so fomite transmission of these viruses does not occur.

There is one more thing about virus infections in general you must keep in mind when you listen further about COVID-19 and how it relates to other viruses. This relates to the issues of virulence and transmission. If you were a virus particle, what would make you the perfect virus”? First, you would have to have enough hosts to infect. With immunization programs, a few people will get a viral infection but it will not spread to create an epidemic. This is because of what’s known as herd immunity”. There just aren’t enough sensitive hosts for the virus to take hold. COVID-19 approaches perfection because there just isn’t herd immunity yet. This will most likely happen one day, though, so the numbers of new cases will drop dramatically. The perfect virus must make the host organism sick enough to cause disease and to create symptoms most beneficial for its transmission. With respiratory viruses, if you didn’t cough and sneeze with them, the virus has less of a chance of spreading. Even so, every virus has a limit and it is entirely possible for a virus to be too virulent for its own good. This is partially the case with viruses like Ebola and MERS, which is also called Middle Eastern Respiratory Syndrome. MERs, interestingly, is another type of coronavirus infection. Viruses that are too virulent just aren’t successful because the infected person is too sick to pass it on to others. The patient might die too quickly so the chances of spread is less. The virus might kill nearly everyone it infects, which also acts against its ability to spread from person to person. The person who is too sick from a virus doesn’t go shopping, hang out with friends, or go to concerts or on vacation. They stay home instead, where the virus runs its course and infects few other people. These types of viruses might create an epidemic but it soon burns out because it isn’t transmitted very well. The super-perfect virus is one that infects people in varying degrees. It will kill some people, which makes it dangerous, but doesn’t kill everyone. Some are sick enough to stay home, while others feel well enough to leave their home to do other things. Still others of us—perhaps the worst-case scenario for us hosts but the best-case scenario for viruses—simply do not know they have the infection. They go everywhere, including on vacation. They might cough or touch a surface, infecting others without really being sick themselves. 7

COVID-19 is about as close to being the perfect virus as one could imagine. It kills some people but not everyone who gets it. This means it isn’t nearly as deadly or as inefficient as viruses liked Ebola and MERS, which kill too many people too quickly to get passed onto others. It is transmitted in ways everyone can relate to. Unlike hepatitis B or HIV— both of which rely on having sex or sharing blood with infected persons—COVID-19 gets transmitted much more easily so hardly anyone can avoid it. It even has a fair number of carriers”, which are those without symptoms that still pass on the disease—even more likely than the sick person who simply stays home. These are the reasons why doctors are more worried about COVID-19 than other viruses that, on the surface, seem much more dangerous than this one. The potential for rapid spread is great in COVID-19 infections, made worse by the fact that almost no one on earth yet is immune to it. It is practically impossible to prevent the disease through quarantining cruise ships, for example. Too many people could walk around the ship and off of it later to spread the disease to others, simply because they have no symptoms. This isn’t to say that containment through quarantine does no good at all; it just isn’t a perfect approach to managing COVID-19. Now, let’s talk about what COVID-19 is in relation to other viruses on earth. Unless you’ve been living under a rock lately, you probably already know that COVID-19 and other coronaviruses are respiratory viruses, meaning that it mainly infects the human respiratory tract. The virus family is called Coronoviridae. These are single-stranded RNA viruses, similar to the virus that causes hepatitis A, Norwalk virus, rhinovirus, which is one of the viruses that causes the common cold, Zika virus and poliovirus. Single-stranded viruses can be called positive-sense RNA viruses or negative-sense RNA viruses. Positive sense viruses can get directly made into proteins necessary to make the offspring virus particles. Negative sense viruses need to have an intermediate step to turn them into positive sense virus RNA that is able to then make proteins. Because of the uniqueness of these viruses in terms of the genetic material they hold, some drug companies feel optimistic that drugs can be made one day that will exploit this feature without harming the human host.

As you will see, it is mainly spread through droplets and exposure to infected fomites, although it doesn’t stay alive on fomites as long as some other virus particles. Coronaviruses have been known about since the 1960s but no one knew it could cause pneumonia until it became the source of the SARS pandemic in 2003. SARS itself means severe acute respiratory syndrome” and causes severe, often life-threatening pneumonia. To date, about seven known coronavirus types exist in nature, including COVID-19. SARS and MERS, which is the Middle East Respiratory syndrome virus, are also types of coronaviruses with lethal potential in humans. We will talk later about how these viruses differ from one another. It is believed that, like other coronavirus infections, it is mainly a seasonal infection that will be worse in the fall through spring months and less common in the summer months, although we have all heard that COVID-19 exists in parts of the world that have no winter. It is likely far too late to expect that any given summer or even global warming will make this virus disappear altogether. Like influenza, it will probably not be as prevalent in the summer but will be guaranteed to come back in the fall. We haven’t even talked about the possibility that it might change each year like the influenza virus does but don’t count this out. When researchers look at the genetic makeup of the different coronaviruses, they really see just a tiny difference in the genes and the makeup of the genes within each of these virus particles. On the other hand, this miniscule change means that the viruses look different to our immune systems and we can easily get infected with one of them, even if we are immune to one of the others. As mentioned, coronaviruses are single-stranded RNA viruses but, unlike some similar viruses, it has a lipid envelope surrounding its capsid. You’ll see later why this is important. As a respiratory virus, COVID-19 and other coronaviruses are an important public health problem because they affect the respiratory tract. Those with preexisting respiratory tract disease simply do not tolerate these kinds of infections well. Respiratory viruses can mainly infect the upper respiratory tract, such as the nose, throat, and sinuses, or they can infect mainly the lower respiratory tract, such as the bronchial tree and lungs. Some of these, like COVID-19, can infect the entire respiratory tract. 9

Most are fall to spring viruses but, if you’ve ever had a summer cold”, you know this is largely theoretical and that some viruses just do not follow this rule. In the winter, the air is drier so the mucous membranes in your nose, throat, and sinuses are more susceptible to viral infections. In addition, the cold weather drives people indoors under closer quarters so the infection has a greater chance of person-to-person spread. Other viruses are also more commonly seen this time of year so double-infections are more possible. This makes this winter phenomenon with regard to respiratory viral infections both an environmental and social issue. There are two types of people who might get any virus infection, including COVID-19. There are people called immunocompetent hosts because their immune systems are relatively strong and they fight off infections relatively easily. These are the people who are most likely to spread the virus, either because they don’t know they have it or have very mild symptoms. Few immunocompetent people will die from a respiratory virus. Immunocompromised hosts are the other classification of people who can get a respiratory virus like COVID-19. Patients with diseases like asthma, COPD, emphysema, cystic fibrosis, or other lung diseases are technically immunocompetent in most cases but, because their lungs are already sick with preexisting disease, they do much more poorly than others who don’t have lung disease. Even smokers who don’t have true lung disease have impairments in the way they clear infections from the lungs so they too are at risk. The truly immunocompromised host can have a variety of reasons why COVID-19 and other respiratory infections are more dangerous. Immunocompromised hosts include those who’ve had bone marrow transplants and those with blood-related cancers. Some of these people have very high numbers of infection-fighting white blood cells but these are largely useless because they simply don’t work efficiently or at all in the fight against infections. Anyone who takes drugs to block their immune system because of autoimmune diseases or prior organ transplants are also immunocompromised hosts. HIV patients are immunocompromised because the HIV virus attacks the immune system directly. Those who take corticosteroids, which are not the same thing as the anabolic steroids some

athletes take, have an increased risk of a serious respiratory infection from COVID-19 and other respiratory diseases. The same is true of people who have low white blood cell counts for any reason. People who are sick with another virus or bacterial infection are overworked fighting infection so they too are immunocompromised. There are other common situations where a person is considered immunocompromised in some way. Pregnant women are slightly compromised, partly because their bodies are primed to be less aggressive in fighting off the foreign fetus they carry. They tend to get sicker in general with viruses and certain viruses, such as the Rubella virus and Zika virus, are known to cross the placenta to infect the baby. This could lead to a miscarriage in pregnancy or to birth defects in the baby. Not much is known yet about the potential for COVID-19 to have these kinds of effects on unborn babies but there have so far been no reports of birth defects or bad pregnancy outcomes with this virus. The elderly are also considered immunocompromised for multiple reasons. They are more likely to have other chronic diseases that make it hard to tolerate even minor infections and are more likely to develop pneumonia from a viral respiratory infection. Diabetics are also somewhat immunocompromised for reasons not yet completely clear. Nevertheless, diabetics tend to get infections that become serious more readily than those without diabetes. Can stress itself make you immunocompromised? This is less well studied but is most likely true. Stress raises your body’s cortisol levels, which negatively affects your immune system. This is why you seem to get sick more easily under stressful circumstances and fight off infections more poorly. Keep this in mind when we talk about strategies to beat COVID-19. All known coronaviruses are considered zoonotic viruses, which mean the potential to spread from other animals to humans does exist. SARS, for example, was believed to first become a human infection after first being one that infected civet cats. Civet cats themselves probably got the infection from bats. MERS, on the other hand, started out as a dromedary camel infection. There are still other coronavirus infections in animals alone that haven’t jumped species to infect humans as well.

Currently, there is nothing to suggest that COVID-19 is any different from other zoonotic coronavirus infections. Researchers believe that bats are the main reservoir for COVID-19 but that there may be some unknown intermediate host between bats and humans. While we talked about the fact that viruses which infect other animals do not usually cause diseases in humans, this isn’t always the case. Zoonotic viruses are common throughout the world and other pathogens, like bacteria, parasites, and fungi can also be zoonotic. The animals themselves may seem healthy but will still harbor the infection. Researchers speculate that 75 percent of novel or emerging viral infections like COVID-19 are zoonotic in origin. Not all zoonotic viruses are identical to the same virus in infected animals. This is because viruses can mutate or change slightly, making them jump more easily from one species to another. It isn’t known if COVID-19 is one of these. Regardless of whether a fundamental change in the virus has occurred, people get zoonotic viruses if they come into contact with the secretions or feces of infected animals. They can also get sick if they live with infected animals that have left the virus particle on fomites, if a flea or tick bites an animal and then bites a human, or if animal feces or the animal meat itself are eaten on food that hasn’t been washed or cooked properly. Raw vegetables, raw fruit, and undercooked unpasteurized eggs can all be sources of zoonotic infections. Keep this in mind for the rest of your life, especially when you eat these things without washing them first. Even drinking water contaminated by animal feces can lead to an infection. Once the virus has officially jumped ship and has become a human infection, it hardly means much that it was once a zoonotic infection. If the virus decides that the human host is just as good or better than the original animal host, it becomes a human infection that is forever passed from one person to another and no longer requires an animal source. The one thing doctors and researchers already know about COVID-19 because they’ve studied the other coronavirus infections that have been around longer is that these are virus particles that mutate easily. A mutation is simply a change in the genetic material that can affect how the virus is perceived by the human host in the future. Big mutations

can lead to new strains of the virus, which is probably how COVID-19 started in the first place. In that way, coronaviruses are important sources for novel infections and have a greater likelihood of mutating into a slightly different strain over time, similar to what happens with the influenza virus. In simple terms, it might mean that one day you will get your annual coronavirus vaccination just like you get an annual flu shot. Doctors just can’t yet predict if this will happen or not. While COVID-19 mainly kills older or sicker people, anyone can get it. In fact, in other coronavirus strains, children are more likely to have symptoms and severe disease than adults. This is fortunately not the case with COVID-19. It also mainly affects the respiratory tract, although other coronaviruses can infect the central nervous system or brain, leading to confusion or death from this complication. Some coronaviruses can persist in the brain, becoming a risk factor for chronic neurological diseases. It isn’t known yet if this can happen in COVID-19 as has happened with other strains of this virus. So, COVID-19 is a new virus but it has several known predecessors that have been around for nearly fifty years or longer. This may be important and valuable in COVID-19 research and prevention because we already know some things about this class of virus particles. As a respiratory virus similar to influenza and the common cold virus, it will likely become part of our everyday lives for the near future at least. Because of this, everything you already know about how to combat these kinds of viruses applies to COVID-19 as well.

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