WHAT IS A VIRUS?
A virus is a microscopic organism which is on the borderline of living and non-living. It is parasitic, meaning that it survives by intaking nutrients from the host to aid it’s nutrition.
Viruses, simply put, are just genetic material in a capsid (protein capsule)!
This genetic material can come in 2 forms! Namely DNA and RNA
Now, you may also think that how is a virus on the borderline of living and non-living?
HOW IS A VIRUS ON THE BORDERLINE OF LIVING AND NON-LIVING?
When viruses are outside the host body, they are unable to sustain as living organisms and are referred to as non-living. BUT, when they enter the host body and take control of it, they are able to multiply and sustain as living organisms.
WHAT CAUSES A VIRUS TO BE HARMFUL?
As said before, a virus is parasitic. Which means that it relies on the host cells for survival
Now, if a virus enters the host’s body, it will control the body of the host
This means that it will also have to intake nutrition for survival. How will it take nutrition? By acting as a parasite and using the host’s body to get it’s required nutrition.
But, how does it take control of the host’s body?
When it enters into the host’s body, it has to go into a cell!
So, virus has it’s own membrane (around it’s capsid).
This membrane will COMBINE with the cell membrane of the host.
Now, the virus can ENTER into the cell and can also DESTROY the cell.
It can cause further rampage through the human body if left untreated and CAN reach the BRAIN (very few strong viruses can do that)
After reaching the brain, it can cause harm to the brain!
A viral disease named “Viral Encephalitis” causes an inflammation in the brain.
What do you mean by inflammation?
When a virus foreign pathogen enters in your body, the body triggers an immune response. This immune response is termed as inflammation.
Now, you might think, that how is Viral Encephalitis harmful?
When inflammation happens, there arises a swelling in the brain which can lead to serious issues such as headache, stiffness of neck (neck hurts when you move your neck’s pivot joint), sensitivity to light (eye hurts a lot when seeing something bright), mental confusion (I AM CONFUSION) and seizures (nerves carry electrical signals, now, if a seizure happens, there are uncontrolled electrical signals causing a change in your behavior, feelings or movements)
TYPES OF VIRUSES
There are 4 types of viruses:-
- Helical viruses- They are made up of a single type of protein which is stacked around a central axis to form a helical-in-shape structure.
- Polyhedral viruses- They are composed of genetic material surrounded by a multi-sided capsid, composed of usually 20 faces, triangular in shape.
- Spherical viruses- They are enclosed in a membrane known as envelope and are more circular in shape. They also have spikes on the surface composed of sugary proteins which assists in sticking and entering the host cells.
- Complex viruses- They look more like a lunar lander and are composed of a polyhedral head, a helical body and legs. The legs attach to the cell membrane so that it can transfer the genetic material.
TRANSMISSION OF A VIRUS
Virus transmission
To spread the infection to more people, a virus has to transmit.
How does it transmit??
If the virus transmits, what it does is that it takes out a fragment of the DNA of the previous organism and then puts it into the other organism, leading the other organism to become infected.
Also, viruses which infect bacteria are known as bacteriophages. Bacteriophages inject their genetic material into the rigid cell wall of the bacteria. Then, when it lays dormant for a while there, it is known as the lysogenic cycle. So, long story short, lysogenic cycle is when Virus DNA lays dormant in Bacteria DNA.
There are many ways by which a virus can be transmitted from one organism to another :-
- Touch- SARS-CoV-2 can be transmitted from the infected to the uninfected through direct contact.
- Exhaled gases- The main gas which is exhaled through our body is Carbon Dioxide (CO2). If a virus also comes along with these exhaled gases, it can transmit to the person which inhales the same gas. For eg- Influenza, SARS-CoV-2
- Exchange of bodily fluids- Diseases like HIV, can enter the body of the uninfected from the infected through the exchange of bodily fluids like blood.
- Contaminated food/H2O- A virus, Norovirus can enter into the body if we eat contaminated food/water.
- Insects- The Zika virus, carried by mosquitoes can transmit from mosquitoes to humans.
HOW IS A VIRUS CREATED???
Viruses are mostly created from genetic materials of old cells. Now, what does this mean? Let’s talk about COVID-19 here. So, it was created from an old, prehistoric cell. Now, as cells mutate, the old cell is no longer used by the specific organism. Therefore, the prehistoric cell can cause harm to the current organism, whilst being at the borderline of living and non-living. Forming a virus.
HOW DOES A VIRUS DIE???
As told before, a virus is on the borderline of living and non-living.
[/word_balloon]So, simply put, neither is it living nor it is non-living
[/word_balloon]Only living things die.
[/word_balloon]So, how can a virus, in itself, die as it is neither non-living nor living?
[/word_balloon]Thus, we can conclude that a virus is indirectly immortal
[/word_balloon]WHAT CAUSES A VIRUS TO CHANGE???
Genetic modifications can….
Sometimes, there are genetic modifications in a virus, but what causes those genetic modifications??
In a virus, there are molecules, known as nucleotides, which form different combinations of the virus.
Now, these nucleotides have a tough work to do.
They have to copy the genome sequence (all the genes) of the virus so that exact same copies can form after reproduction…
Now, sometimes the copy of the virus can be different.
This can lead to a stronger virus or a weaker one.
When this happens, we say that the virus has mutated.
MOST DANGEROUS VIRUS OF ALL TIME IN TERMS OF MORTALITY RATE
- HIV (Human Immunodeficiency Virus)
The most dangerous virus of all time is the HIV virus.
The mortality rate of the virus is 99.9999973475%.
Now, such a high percentage confuses people
This means that in all time, only 1 person has been cured of HIV till date
There have been 37.7 million people who have been infected with this virus, and till date, only 1 has survived
The only person to have survived after being infected from this virus had been cured of the virus by a process called Stem-cell transplant.
All the cells of the body of the woman were destroyed by a process known as high-dose chemotherapy.
Then all the cells from the body of another person were transplanted into the woman,
Thus, she is still in her recovery period and is en route to recovery.
2. RABIES
This is the most feared virus…
[/word_balloon]It is caused by dogs.
[/word_balloon]It is a deadly disease which destroys the brain.
[/word_balloon]It can be fatal in most circumstances with a mortality rate of 99%.
[/word_balloon]In order to survive, you have to consult a doctor before symptoms appear which happens once in a blue moon as people won’t even know they have the disease if they show no symptoms
[/word_balloon]But, on the bright side, it is preventable through vaccination….
[/word_balloon]3. EBOLAVIRUS
Vaccine making for this virus is impossible…. (only 1 vaccine has been approved yet)
The average fatality rate of the Ebola Virus is about 50% on average. This means that almost half of all the people infected with this virus die. If that’s not horrifying, there is no treatment for this virus as it constantly keeps mutating, so it becomes impossible for scientists to make a vaccine. So, it’s all up to your immune system if you want to survive. Also, for the Zaire Strain Of the Virus, the mortality rate is 68%.
Also, there is only 1 vaccine for this disease, the Ervebo vaccine, which is 97.5% effective at preventing the virus. Also, this vaccine is only eligible for people who are older than 18 years. This vaccine is made from the Vesicular Stomatitis Virus (EVD). Now, what scientists did was they took the EVD virus and removed it’s surface protein and replaced it with Zaire strain of the Ebola Virus. This will evoke an immune response against the Ebola Virus.
4. SMALLPOX
Even though the WHO declared Smallpox to be eradicated from the world in 1980, this disease before 1980 had caused rampage across the world, with 1 in every 3 being infected with it. People who were infected and then recovered were often left with deep and permanent scars, often blindness. It had a mortality rate of 30%
5. HANTAVIRUS
