Covid for dummies - part deux - Blood Cancer Uncensored

Virus for dummies part 1 was introductory in nature and talked a lot about viruses in general, less about covid-19 (covid) specifically . For those who are interested in knowing more about covid in detail, here is part deux with the usual disclaimer. I am not a doctor nor scientist. Some accuracy in what follows is sacrificed for the sake of dumbing things down and some because I am just not smart enough to understand it all. With that said, here goes.

First we need a brief refresher from part one. A virus is a tiny piece of genetic junk wrapped in a protein covering. It is not alive in the traditional sense of life, maybe not dead as we think of dead either. Lets call it the undead, like invisible dancers in the thriller music video or whitewalkers in Game of Thrones.

There is a whole family of respiratory viruses called coronaviruses. They can be mild, like the common cold. Or they can severe, like Middle East respiratory syndrome (MERS), that can kill up the 30% infected. The name corona comes from Latin for crown, itself borrowing form Greek for garland or wreath. When seen under an electron microscope, coronaviruses have a little crown of spikes called peplomers. Pelpomers are proteins on the surface of the virus that help it bind to the host cell.

Covid is short for coronavirus disease. The number 19 is added because that’s the year the virus appears to have jumped from a bat to a human in Wuhan. More on that later.

Another name for covid is SARS-Cov-2, severe acute respiratory syndrome coronavirus 2. That name is significant because it describes covid 19 as a “strain” or SARS, a respiratory virus that struck in 2009. Strains are genetic variants, things that are similar but different. Long grain and short grain are strains of rice. SARS 2 is a strain of SARS 1, both are strains of the family of coronaviruses. There are a couple hundred other strains of the coronavirus known more commonly as the common cold.

We all know how covid gets in. Someone sneezes on us or we touch a surface with covid on it and then touch our mouths or our noses. Once inside us, covid uses those little spikes (peplomers) to bind to lung cells. Remember cells for dummies? Cells are the building block of life. Each cell has genes in its dna that instruct it how to work. One thing lung cells do is transfer oxygen from the lungs to red blood cells to in turn transfer oxygen to our vital organs. We obviously do not want anyone changing those instructions, which is exactly what covid does.

Once the covid virus binds to a lung cell, it releases its bad gene into the cell giving the cell a new set of instructions. Then it does what viruses do best. It tricks the cell into replicating the virus over and over and over. Think of a computer virus that gets into your email account and sends out millions of emails to your directory list.

So why is covid 19 so much worse than a coronavirus cold? For that, we have to go back to the bat in Wuhan. Coronaviruses, just like flu viruses, can live in animals or humans. When viruses live in humans for a long time, we develop personal and herd immunities to them. Our body makes antibodies that recognize viruses and neutralize them. Herd immunity is where all our neighbors have immunity, limiting the number of available hosts for viruses.

When viruses jump from animals, we do not have any immunity to them. The Spanish flu of 1918 (H1N1) , which some say originated in Kansas or France, is believed to have jumped for a bird to a human, or perhaps a bird to pig to a human. It infected about one quarter of the world’s population and killed an estimated 50 million people.

Unlike covid, the Spanish flu did its worst on those between the ages of 20 and 40.

The working theory on covid is that bats have harbored it for years. Then it jumped from a bat to a human at a market in Wuhan. People get sick from animal diseases now and then, so that in itself was no big deal. What was bad was when covid mutated in a way that it jumped from human to human. That’s when all hell broke loose. Some infectious disease experts immediately knew a novel virus spreading in one city in China threatened the world, the rest of us not so much.

While not immune to covid, we had all become somewhat immune to virus pandemic panic. We are too young to remember the Spanish flu. SARS, MERS, Ebola and Swine flu has all been hyped as pandemics that would sweep the world. But they never lived up to the hype, I cannot name one person who came down with any of these illnesses. Many of us and our governments were lulled into a false sense of security thinking covid was just another over hyped virus. I know that’s what I thought.

Covid, it turns out, is different from its cousin, SARS and from the flus we have seen. Covid is much more contagious than the flu. Also we see enough types of flu where we, and the herd of people in our communities, have some built in immunity. Covid is so novel, it takes our bodies longer to figure it out and create antibodies to fight it. What makes covid even more dangerous is that it can be in its most infectious stage early on when people have no symptoms. People are said to be “shedding” a virus when they are contagious and release virus particles into the environment. When people shed viruses for days before getting symptoms, both they and those around them can be less vigilant.

So what is the big deal with all the ventilators? This is where it gets scary. Imagine your lungs as an upside down oak tree with two main trunks splitting outward, the left and right lobes of your lungs. From these trunks extend many branches forming our upper, middle and lower lobes. At the end of the branches are leaves, in our lungs we call these leaves alveoli. Alveoli to humans are what leaves are to trees. Leaves use photosynthesis to convert sunlight into energy to feed the tree. Alveoli are the tiny air sacs that allow the lungs to pass through oxygen to the blood.

Most people who get covid do fine, for more than 80% its not much worse that its coronavirus cousin, a bad cold. Some will develop viral pneumonia where parts of the lungs get inflamed. Something like 2% of covid cases progress to acute respiratory distress syndrome (ARDS). These are the people most likely to need mechanical ventilation. If 1,000,000 people in New York get covid, 2% of that is 20,000, hence the need for 20,000 ventilators. New York city has over 8 million people. You can do your own ventilator math is your think half of the city will ultimately infected, as some predict the case will be.

Think of ARDS as a type of pneumonia that covers all of both lungs, not just one or two spots. The alveoli all become inflamed as our bodies own immune system kicks into gear. The fluid from that inflammation fills the alveoli and blocks the transfer of oxygen which wants to diffuse through the thin membranes of the alveoli to the capillaries where oxygen can be transported to the heart and our other vital organs.

Unable to breathe on their own, many with ARDS are sedated and have a tube put down their throats into their lungs where life saving oxygen is forced into the lungs by a ventilator. This requires a lot of monitoring by experienced medical personnel. Experience tells them this works best with people lying on their stomachs. People might be on the ventilator for many days to buy time for their own body to heal their lungs and allow them to breathe on their own. Now imagine in New York city hundreds, if not thousands, of people filling hundreds, if not thousands, of beds lying on their stomachs kept alive by ventilators and a stressed medical staff working double shifts to save them.

Its all made worse by the fact that it appears that most people who go on ventilators will not survive. The survival rates for covid cases on ventilators vary, but early studies have it less than 50%. Even if a ventilator gives someone only a 25% chance to live, I think we can all agree everyone deserves that chance. And I hope this discussion has been helpful to those readers who do not fully understand the ventilator shortage debate raging all over the world. The stark reality is that within the next few weeks we might see doctors in the US and other countries choose who gets on a ventilator and who dies if there are not enough ventilators to go around. Indeed there are hospitals drafting a very grim protocol right now creating guidelines for what happens if there are not enough ventilators. That might mean taking a ventilator from your 85 year old parent and giving it to your 40 year old child if both are sick.

Sobering stuff indeed. But there is plenty room for hope. This is not 1918 when the Spanish flu hit. We have learned social distancing to some extent and that will save thousands of lives. And covid is no great mystery to our scientists, they know exactly what it looks like and exactly how it reproduces. The race is one to find a treatment, cure or vaccine and the brightest minds in the world are in the race and on our side. One promising treatment is as simple as collecting covid antibodies from recovered covid victims and giving them to people who have covid. Another treatment has them using monoclonal antibodies similar to those used to treat cancers. The spikes on the covid virus it uses to bind and infect our cells are a great target for biomedical engineers to design new drugs, or find drugs we already have, to bind to the virus and neutralize it.

My glass half full prediction is this. Most places will peak in the next month or two and the worst will be over. As most coronaviruses have done, covid will burn out some on its own as the summer approaches. That will buy time and before covid kicks up again next fall we will have at least some treatments for it, if not a vaccine. We will also have some more degree of herd immunity. And social distancing will be more natural for us. I saw a scary prediction 200.000 will die in the US from covid. With a population of 330 million, that’s less than one in a thousand of us dying, so while scary, not terrible odds for us individually.

And here is a final thought in the “there is always a silver lining to every cloud” category. The world’s experience with covid will change public consciousness of how disease spreads and provide all of us with cll some increased margin of safety going forward with the spread of other diseases reduced by new hygiene practices. I do not know that I personally will ever touch a doorknob again without the thought some microscopic pest is lurking on it. I do not plan on living the rest of my life scared, but I think I will be, as will others, cleaner and safer going forward.