How do viruses work?
A virus is nothing but a fragment of DNA looking for host cells so it can survive.
Cells are stand-alone living entities. They are living structures that grow, reproduce, and help sustain life. They can do this because they have the right proteins, enzymes, and amino acids. Viruses are different. Viruses are not self-sustaining. They need host cells in order to live and reproduce.
A virus is just a particle that release information to make copies of itself. It’s a deadly, tiny, copying machine.
Here’s the structure of a virus:
Nucleic Acid- a set of genetic instructions, either DNA or RNA
Coat of Protein - which surrounds the DNA or RNA to protect it
Lipid Membrane - Depending on the type of virus: Enveloped viruses have a lipid membrane that surrounds the protein coat. Naked Viruses do not have a lipid membrane.
So unlike human and bacteria cells, viruses do not contain the needed enzymes to carry out chemical reactions for life. To survive, viruses latch onto to host cells and hijack the cell’s enzymes to make more virus particles.
What’s an Enzyme?
Enzymes help speed up chemical reactions in the human body. They bind to molecules and alter them in specific ways. Enzymes are essential for respiration, digesting food, muscle and nerve function, along with thousands of other roles.
Since viruses do no have the right enzymes they cannot do what other cells can do.
How viruses invade our cells:
Here’s the process:
Virus attaches to a host cell.
They insert genetic instructions on how to make more virus particles.
The host cell follows these instructions.
New viruses are made inside the cells.
The new viruses break free from the host cell and find new host cells to infect.
So what’s the danger?
Viruses are part of our daily lives. We’re constantly in contact with foreign pathogens. Most of the time nothing happens and we’re fine. Sometimes we get sick and have symptoms. Then very rarely, we will have an outbreak of a very strong virus.
Virus cells kill their host cells or disrupt cell function when they leave to find a new host. If a virus isn’t stopped they will continue to destroy cells, killing the body from the inside out. Again, most of the time our bodies will fight the virus off.
How do we protect ourselves?
There is no cure for viruses. Your body is actually the best defense. Your immune system has multiple ways of fighting all sorts of pathogens.
Here’s how:
Pyrogens: When the body is infected, your immune system responds by producing chemicals called pyrogens. Pyrogens cause the temperature in your body to increase. The fever slows the rate of virus reproduction.
T cells: A special cell of the immune system called a T cell circulates looking for infections. One type of T cell is called a cytotoxic T cell because it kills cells that are infected with viruses with toxic mediators. Cytotoxic T cells have specialised proteins on their surface that help them to recognise virally-infected cells.
Interferons: Infected cells release small proteins called interferons which interfere with the virus’ ability to replicate. They also warn nearby cells of infection.
Antibodies: Viruses can also be removed from the body by antibodies before they get the chance to infect a cell. Antibodies are proteins that specifically recognise invading pathogens and bind (stick) to them.
Other defenses: white blood cells like natural killer cells, macrophages, cytokines, etc.
*For more information on your immune system, check out our more extension blog.
When our first lines of defense do not work against a virus and it’s able to multiply, our body will send it reinforcements. White blood cells call for more white blood cells. Our bodies will use all lines of defense to slow the virus. This is when symptoms actually kick in. Coughing, sneezing, runny nose, fever, etc. These symptoms are a result of how our bodies are expelling the virus particles from our bodies.
But sometimes our own immune system can lead to serious illness.
Our immune system uses inflammation as a tool for healing. Imagine a fire (virus) breaks out in a city. We call for help from our first responders (white blood cells). Our bodies have a way of expanding tissue and cell walls so that the reinforcements can get through. Imagine if we could expand highways and move buildings so firefighters could get through.
Inflammation is a rush of cells to help fight an infection or restore tissue. To do this, your body dilates the vessels in the area to allow more cells to come in.
What we saw with Covid-19, as our bodies are trying to protect themselves, it can also take a toll on us. Cytokines (signaling molecules) create more inflammation. And too much inflammation can lead to secondary infections like bacterial or viral pneumonia. This can lead to a secondary illness which makes the body weaker and sicker. A flood of cytokines creates a cytokine storm. Which is meant to protect the body, but can lead to acute respiratory distress syndrome (ARDS) damaging the lung cells the body is trying to save.
A second infection leads to more immune responses and more inflammation. This can be too much on the body, making it weaker and leading to organ failure.
Medicine:
Antibiotics: stop or kill bacteria, but do not work with viruses.
Antibiotics are giving if there’s a secondary infection. Bacteria cells are different than virus particles.
Immunizations (Vaccines): Contains a deactivated virus or genetic code of the virus, which activate the body’s immune system to produce a natural defense against the disease (antibodies).
Antivirals: reduces the reproduction of viral cells by stopping the infection process. And it depends on the virus and medicine. Some antivirals prevent the virus from fusing to the healthy cell by blocking a receptor that helps bind the virus to the cell.
Types of Viruses and their impact on the world:
Ebola: Zoonotic virus (animal to animal, then to human) broke out in Africa in 2014-2016.. Includes stomach pains and even hemorrhaging, bleeding, bruising, rashes. Over 11,000 deaths. We now have a vaccine.
HIV: “Human Immunodeficiency virus” a virus that attacks the immune system. If not treated it leads to AIDS (the infection “Acquired Immunodeficiency syndrome”. There is not cure. HIV is a life long virus. But it can be controlled. Hundreds of thousands die each year around the world.
Rabies: Zoonotic disease. Estimated 59,000 deaths a year.
Smallpox: Disease that’s been around for thousands of years and kills 3 of 10 people who have it. Causes rash and bumps on body. Estimated 300 million died in the 20th century alone. Small pox influenced the world and our history. Wars were won and lost because of outbreaks of small pox. This virus even wiped out indigenous nations. The vaccine eradicated it.
Influenza: The FLU virus has many strands and adapts every year. About 35,000 had died in the US in 2018.
The Spanish Flu: (H1N1) killed 50-100 million people between 1918-1920.
MERS-CoV: Middle East respiratory syndrome coronavirus (MERS-CoV) is a virus transferred to humans from infected dromedary camels. It is a zoonotic virus. 27 countries have reported cases since 2012, leading to 858 known deaths due to the infection.
H7N9 Flu: A new bird flu strain. Has a 60% death rate, but it doesn’t spread efficiently.
SARS-CoV1/SARS-CoV2: The outbreak of SARS-CoV-2 began in December 2019, and by March 15, 2021, the global case rate had reached 120 million and deaths had reached 2.65 million and is still ongoing. We now have a vaccine for Covid-19.
Viruses can be extremely dangerous. Not all viruses are deadly. Some act very fast. Others can stay dormant in the body for years.
To best protect ourselves from viruses we need to:
Support our immune systems through a well balanced diet with plenty of vitamins and nutrients, along with consistent exercise, stress management, adequate sleep, and protecting ourselves from toxicity and other forms of immune suppressors.
Safe sexual practices can also protect us from sexually trasmitted diseases.
Vaccines have played a major role in eradicating viruses.
Safe hygiene such as hand washing, covering mouth when coughing or sneezing, cleaning and cooking food properly, etc.