Sunday 9 August 2020

CORONAVIRUS DIARIES XIII

 

“If you would be a real seeker after truth, it is necessary that at least once in your life you doubt, as far as possible, all things.” - Rene Descartes 

Today, I am interviewing a medical expert, researcher, published author of many scientific, peer-reviewed articles and medical textbooks, a well-known professional, and an academic of many years, who currently works for a government agency that supervises medical care in Australia, ensuring that the public are protected and that they enjoy safe, effective and evidence-based treatment and care. I shall refer to this person as Dr X.
 
Jammy: Dr X, thank you for agreeing to this interview on the COVID-19 pandemic. Your expertise is valued and your time is appreciated. 

Dr X: you’re welcome, I am happy to provide as much up-to-date and accurate information as I can in a language that an average lay person can understand. 

Jammy: Please explain to me, what are viruses? 

Dr X: Viruses are interesting aggregates of organic matter, that technically are not able to be classified as “living”. They don’t respire, they don’t respond to stimuli, they cannot reproduce themselves and many of them, if purified, can be crystallised like sugar or salt and stored in a jar on a shelf, unchanging for many years. They are of two major types, depending on whether they possess their genetic material in the form of RNA or in the form of DNA – not both like our cells have. 

Jammy: So are they cells? 

Dr X: No, they are not cellular. They are very simple compared to cells possessing in most cases only a little genetic material in their core and a surrounding, protecting shell of protein, with or without an external envelope of lipid, depending on the virus type. They are exceedingly small. A red blood cell of a human is 7,500 nanometres (a nanometre is a billionth of a metre), a typical bacterium is around 1,000 to 2,000 nanometres, and a large, complex virus is only around 400 nanometres, while a small one is about 25 nanometres. 

Jammy: So if they cannot reproduce themselves, how do viruses multiply? 

Dr X. They are expert fraudsters and master deceivers. When viruses come into the body, their external proteins latch onto cell receptor molecules and thus they enter into living cells. Inside these, they take over the metabolism of the cell and they force the cell to make more and more viruses instead of more cell. As the cell fills up with viruses, it bursts, is destroyed and thousands of new viruses emerge, to infect more body cells, or come out of the body to infect other people. 

Jammy: Hmmm, seems like a pretty pointless existence… 

Dr X. Well, no more pointless than many living organisms, or even some people! 

Jammy: When viruses come into the body, can’t we take antibiotics to destroy the viruses? Just like we do with bacterial infections? 

Dr X. Bacteria, fungi and protozoa can be relatively easily managed with antibiotics and other drugs because they are living organisms with their own metabolism, which in many cases is quite different to human cells. Antibiotics interfere with the metabolism of these microorganisms, killing them or suspending their growth so the body’s immune cells can destroy them. Viruses, as we said, are not alive and do not metabolise. Thus they are not susceptible to antibiotics and most antimicrobial drugs. 

Jammy: But AIDS is caused by a virus and HIV infection can be treated effectively nowadays with drugs, can’t it? 

Dr X: Yes, HIV infection can be effectively managed nowadays with a cocktail of specific drugs because HIV is a rather special virus. It is a virus which can only make the cell manufacture more virus by getting the cell it infects to first make a special enzyme that doesn’t exist in human cells (the enzyme is called reverse transcriptase). Many of the anti-HIV drugs interfere with this special enzyme’s activity in cells, hence preventing viral replication in cells. 

Jammy: So, theoretically, it’s possible to have a drug that interferes with COVID-19 replication in cells? That would get rid of virus from the body, and hence infection? 

Dr X: This is much more difficult. COVID-19 is a more or less quite ordinary virus, which comes into cells and takes over cell metabolism easily, utilising all of the cell’s own enzymes and nutrients to make more virus. If we interfere with these cellular metabolic pathways with a drug, we would be interfering with the metabolic process of all cells in our body, which could effectively kill us. A rather drastic way of overcoming a viral infection. 

Jammy: What about hydroxychloroquine? Doesn’t that help with overcoming COVID-19 infection? 

Dr X: For a while, some initial studies with it showed promise. Unfortunately, examination of these initial trials with this drug, indicated that they were conducted in a rather haphazard manner and the results of the studies were not interpreted in a scientific manner. More trials were conducted, and at this time, there are very limited data to support the use of hydroxychloroquine for the treatment or prevention of COVID-19. Clinical evidence is emerging, but results are inconclusive. Besides, prolonged use of hydroxychloroquinone (especially in compromised patients or together with other drugs) has numerous side effects, some of which are life-threatening. Hydroxychloroquine is definitely not the wondrous cure for COVID-19 as some very vocal people are vehemently suggesting – I wonder if these people have shares in drug companies manufacturing hydroxychloroquine? 

Jammy: What about a vaccine against COVID-19? 

Dr X: Vaccines are the standard, safe, cheap and effective way to prevent a whole variety of different viral diseases, for example: Polio, measles, hepatitis B, rubella. Will a vaccine be developed as easily for COVID-19 as for the diseases I just mentioned? The answer is maybe yes, maybe not. The “maybe yes” comes from the observation that in animal studies, coronaviruses stimulate strong immune responses, which seem capable of knocking out the virus. Recovery from COVID-19 may be in large part due to effective immune response. The “maybe not” comes from evidence just as strong, at least with earlier SARS and MERS viruses, that natural immunity to these viruses is short-lived. In fact, some animals can be reinfected with the very same strain that caused infection in the first place. 

Jammy: Some people suggest that we should not bother with restrictions and precautions and just rely on herd immunity to get us over the pandemic. 

Dr X: Herd immunity occurs when a large portion of a community (the herd) becomes immune to a disease, making the spread of disease from person to person unlikely. As a result, the whole community becomes protected not just those who are immune. Often, a percentage of the population must be capable of getting a disease in order for it to spread. This is called a threshold proportion. If the proportion of the population that is immune to the disease is greater than this threshold, the spread of the disease will decline. This is known as the herd immunity threshold. What percentage of a community needs to be immune in order to achieve herd immunity? It varies from disease to disease. The more contagious a disease is, the greater the proportion of the population that needs to be immune to the disease to stop its spread. For example, measles is a highly contagious illness. It is estimated that 94% of the population must be immune to interrupt the chain of transmission.

There are some major problems with relying on community infection to create herd immunity to the virus that causes COVID-19. First, it isn’t yet clear if infection with the COVID-19 virus makes a person immune to future infection (as we said, that is one of the problems with making a protective vaccine against this virus).

Even if infection with the COVID-19 virus creates long-lasting immunity, a large number of people would have to become infected to reach the herd immunity threshold. Experts estimate that in the USA, 70% of the population (i.e., more than 200 million people!) would have to recover from COVID-19 to halt the epidemic. If many people become sick with COVID-19 at once, the health care system could quickly become overwhelmed. This amount of infection could also lead to serious complications and millions of deaths, especially among older people and those who have chronic conditions. 

Jammy: Oh dear! We are in a bind… So what can we do? 

Dr X: We must slow the spread of the COVID-19 virus and protect individuals at increased risk of severe illness, including older adults and people of any age with underlying health conditions. To reduce the risk of infection we must all:

  • Avoid large events and mass gatherings.
  • Avoid close contact (within about 6 feet, or 2 meters) with anyone who is sick or has symptoms.
  • Stay home as much as possible and keep distance between yourself and others (within about 6 feet, or 2 meters) if COVID-19 is spreading in your community, especially if you have a higher risk of serious illness. Keep in mind some people may have the COVID-19 virus and spread it to others, even if they don’t have symptoms or don’t know they have COVID-19.
  • Wash your hands often with soap and water for at least 20 seconds, or use an alcohol-based hand sanitiser that contains at least 60% alcohol.
  • Wear a cloth face covering or face mask in public spaces, such as in shops, where it’s difficult to avoid close contact with others, especially if you’re in an area with ongoing community spread. Dispose of the face mask safely in a rubbish bin.
  • Cover your mouth and nose with your elbow or a tissue when you cough or sneeze. Throw away the used tissue in a rubbish bin.
  • Avoid touching your eyes, nose and mouth.
  • Avoid sharing dishes, glasses, bedding and other household items if you’re sick.
  • Clean and disinfect high-touch surfaces, such as doorknobs, light switches, electronics and counters, daily.
  • Stay home from work, school and public areas if you’re sick, unless you’re going to get medical care. Avoid public transportation, taxis and ride-sharing if you’re sick.
  • Get tested for COVID-19 if you have symptoms and self-isolate at home until you get the results.

Jammy: Thank you Dr X, sound advice indeed! 
 Dr X: My pleasure. Stay safe and take care.

7 comments:

  1. A very interesting and informative piece.

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  2. Thank you to Jammy and Dr. X for a very good, easy to understand read on covid!

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  3. Great post, understandable and easy to follow. Great info on viruses and why we can't use ordinary drugs and antibiotics on them.

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  4. So good to read something sensible and down-to-earth about this pandemic. Thank you.

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  5. If viruses aren't alive, we're trying to kill something that isn't alive! Crazy!

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  6. We are in stage 3 of reopening in Toronto and so far so good. Our cases have been under 100 a day for about a week and hopefully that downward trend will continue. But I am not letting my guard down. I fear a second lockdown may loom much the same as Australia and other countries have happened.

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  7. Vladimir Putin says Russia has approved world's first coronavirus vaccine, despite WHO warnings about rushing it through. See:
    https://www.abc.net.au/news/2020-08-11/russia-approves-first-coronavirus-vaccine-vladimir-putin-says/12547608

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