1. Viruses

2. What are viruses?
They are not living things. Viruses are considered non-living because they do not use energy to grow or to respond to their surroundings, and they don’t have the needs of living things. 
Viruses only do one thing living things do – they reproduce, but they can only reproduce inside another organism.

3. What are viruses?
They are very, very small. Much smaller than bacteria.
Viruses are so small that they cannot be seen with the type of microscopes found in most high schools. 
Instead, scientists must use electron microscopes to view viruses.  Viruses are much smaller than the cells they infect.
See how small some are!

4. What are viruses?
Viruses can infect almost every living thing (all of the kingdoms), but each virus can only infect a few types of cells in only a few specific species. Examples:
The flu virus can only infect the throat cells of humans.
A virus that infects a tomato plant cannot infect a human.

5. Naming Viruses
Viruses are not named like living organisms using binomial nomenclature. 
Often, a virus is named after the disease it causes.  Some viruses are named after the person(s) who discovered them.

6. Examples of Viruses
Viruses vary in their shape and size.  Below are some pictures of various viruses. 
Rabies Virus
Flu Virus
Ebola Virus

7. Structure of Viruses All viruses have two basic parts:
1. an inner core of DNA
2. an outer coat of
protein

8. The outer coat provides protection for the virus and is made of protein.  The coat is what determines what type of cells the virus is able to invade.
The inner core is made up of a virus' DNA.  It is this genetic material that holds the instructions for making more viruses.

9. Virus Reproduction

10. Diseases Caused by Viruses
Measles
Meningitis
Mononucleosis
Norwalk Virus
Rabies
Rotavirus
West Nile
HIV / AIDS
Chicken Pox
Common Cold
Pink Eye
Ebola
Hepatitis
Flu

11. What is smallpox?
Smallpox is a contagious, deadly infection caused by the variola virus.
Before there was a vaccine, smallpox used to cause death all around the world. Thanks to widespread use of the vaccine, the last natural case of smallpox occurred in And in 1980 the World Health Organization (WHO) declared that the spread of smallpox was stopped and that the disease had been wiped out.

12. Small Pox

13. Because there is a slight risk of serious reactions and even death from the smallpox vaccine, routine smallpox immunization ended in the United States in 1972.
Smallpox virus is known to exist in labs at the Centers for Disease Control and Prevention (CDC) in the U.S. and at the Institute of Virus Preparations in Siberia, Russia.

14. Treatments for Viral Infections
Antibiotics don’t work against viral infections.
Vaccines help prevent some viral infections such as chicken pox and flu.

15. How do vaccines work?
Most vaccines trick the body into thinking it has been infected with a virus.
The body releases its own natural defenses to fight off the phony viral infection.
The body is then on “alert”. It will recognize and fight off the virus if it really enters the body.

16. How do vaccines work?
Some viruses can mutate or change their appearance. That’s why you need to get a new flu shot every year. This year’s flu virus will not look like last year’s, so your memory cells will not recognize it from last year’s vaccination.