1. KEY CONCEPT Some viral diseases can be prevented with vaccines.

2. Viruses cause many infectious diseases
There are many examples of viral infections.
common cold
> 200 viruses
Mutate often

3. Viruses cause many infectious diseases
There are many examples of viral infections.
Influenza
Spreads quickly and
may cause epidemics
or pandemics
New vaccines each
year

4. Viruses cause many infectious diseases
There are many examples of viral infections.
SARS
Severe Acute respiratory
Syndrome
Viral respiratory disease
that appeared in 2002

5. Viruses cause many infectious diseases
There are many examples of viral infections.
HIV
Human Immunodeficiency
Virus
Retrovirus that destroys
white blood cells of the
Immune System and
eventually causes AIDS
(Acquired Immunodeficiency
Syndrome)
HIV-infected white
blood cell
The body has natural defenses against viruses.

6. Vaccines are made from weakened pathogens.
A vaccine stimulates the body’s own immune response.
Vaccines prepare the immune system for a future attack.
Vaccines are the only way to control the spread of viral disease.

7. Vaccine
Substance that stimulates the body’s own immune response against invasion by pathogens.
Made from the same pathogen that it is supposed to protect against. Made of weakened viruses or parts of viruses that will cause the body to make immunity.
Diseases that have vaccines: chicken pox, hepatitis A, mumps, measles, rabies, influenza
Diseases that do not have vaccines: colds, SARS, HIV, West Nile virus

8. Norwalk Virus
Bad virus for cruise ships: vomiting and diarrhea