Viruses can infect and multiply in host cells, disrupting their normal processes and causing disease. A virus consists of hereditary material surrounded by a protein coating. Vaccines prepared from dead or weakened viruses can prevent disease by stimulating the immune system without causing illness. Interferon is a protein released by infected cells that slows or stops viral replication.

1. Chapter 2 Section 3 – Viruses
1. disease – a condition that results from the
disruption in function of one or more of an
organism’s normal processes

2. 2. virus – a strand of hereditary material
surrounded by a protein coating that can infect
and multiply in a host cell
3. host cell – a living cell in which a virus can hide
until activated by environmental stimuli

4. 4. vaccine – a preparation made from dead or
weakened pathogens (bacteria or virus) that can
prevent disease.
5. antibiotic – a preparation
that limits the growth of bacteria;
antibiotics are used to treat
bacterial infections

5. 6. interferon - a protein released by animal cells,
usually in response to the entry of a virus, that
has the property of slowing or stopping virus
replication.

6. - The first vaccine was developed in 1796.
- Edward Jenner developed a vaccine for smallpox