Transcript Vaccination and HIV

Vaccines and Opportunistic
Infections
EQ: How does your body react to
vaccines and opportunistic
infections?
Vocabulary: antiseptics, antibiotics,
antibiotics resistance, vaccines,
opportunistic infections, HIV, AIDS
Many methods are used to control
pathogens.
• Antiseptics kill pathogens outside of the body.
– do not target specific pathogens
– examples include vinegar and soap
– Can be bacteriacidal or bacteriastatic
• Antibiotics kill pathogens inside the body.
– target one specific bacterium or fungus
– Usually made from bacteria, fungus
– Destroy/inhibit formation of cell wall
– not effective against viruses (because viruses do not
have cell wall)
– examples: penicillin (from fungi)
• Antibiotic resistance can cause medicines to become
ineffective.
– Some bacteria in a population have genes that make
them immune to antibiotics.
– These bacteria spread the gene, making the antibiotics
useless.
A bacterium carries
genes for antibiotic
resistance on a plasmid.
A copy of the plasmid is transferred
through conjugation.
Resistance is quickly
spread through
many bacteria.
Check for Understanding
1. Explain why the same medicine does not work
against the same bacterial infection the next time
you are infected?
Check for Understanding
2. When you have a flu and the doctor gives you
medicine, explain what the antibiotics are for?
Vaccines artificially produce acquired
immunity.
• Vaccines also control pathogens and disease.
– given to prevent illness
– contain the antigen of a weakened pathogen
HIV and AIDS
• Opportunistic infections.
– occur because white blood cells cannot fight infections
– if immune system were healthy, would fight these
infections
Leukemia is characterized by abnormal white
blood cells.
• Leukemia is cancer of the bone marrow.
– characterized by immature white blood cells
– causes weakened immune system
HIV targets the immune system.
• The human immunodeficiency
virus (HIV) is a virus.
– attacks and weakens the
immune system
– is transmitted by mixing
infected blood with a bodily
fluid, sexual intercourse,
mothers to child, and needles.
• HIV infection leads to AIDS.
dead
T cell
T cell
activated
B cell
antibody
HIV
– HIV reproduces in and destroys T cells.
– The body cannot replace T cells fast enough.
– T cells cannot help in immune responses.
• AIDS is acquired immune deficiency syndrome.
– several opportunistic infections
– very low amount of T cells