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Antibiotics
- Drugs that fight infections caused by bacteria e.g. Penicillin
- 2 types:
- Bactericidal Antibiotics
- Kill bacteria by disrupting:
- Cell wall, cell membrane or action of essential enzymes
- Bacteriostatic Antibiotics
- Prevent bacteria from reproducing usually by disrupting proteins synthesis
- Broad spectrum antibiotics affect a wide range of different types of bacteria
- Narrow spectrum antibiotics only affect specific types of bacteria
Antivirals
- Antivirals treat infections caused by viruses
- Work by inhibiting replication of the virus, e.g. acyclovir (Zorivax) for herpes infections
Vaccines
- Contain antigens that trigger immunity but do not cause the disease
- Induce long-term immunity to specific pathogenic infections by stimulating production of memory cells
- Developed to have active artificial immunity
Attenuated vaccines
- Weakened form of pathogen
- Generally unable to cause disease
- Strain replicates in vaccine recipient
- Causes infection with undetectable or mild symptoms
- Results in long-lasting immunity
- Advantages
- Single-dose usually sufficient to induce long-lasting immunity
- Due to multiplication of microbe in body
- Continued stimulation of immune system
- Vaccine has added potential for being spread
- “Disease“ after immunisation could be spread to un-immunised individuals inadvertently
- Disadvantages
- Have potential to cause disease in immunocompromised individuals
- Pregnant women should also avoid immunisation with attenuated vaccines
- Attenuated vaccines in use include:
- Sabin polio vaccine
- MMR
- Yellow fever (jaundice)
Inactivated vaccines
- Used killed or inactivated version of pathogen
- Advantages
- Generally considered to be safe
- Easy to manufacture
- More stable than live vaccines
- Disadvantages
- Immunity not as prolonged therefore boosters will be required for ongoing immunity against diseases
- E.g. Polio vaccine
Toxoid Vaccines
- Use a toxin made by the pathogen
- Immune response targeted to the toxin instead of the whole pathogen
- Advantages
- Toxoid vaccines are safe as long as they cannot cause the disease they prevent
- Stable, less susceptible to changes in temperature, humidity and light
- Disadvantages
- Immunity is not prolonged, may need booster shots for ongoing immunity
- E.g., tetanus
Subunit Vaccines
- Uses specific pieces of the pathogen to focus immune response to a specific target
- Advantages
- Immune response that is targeted to key parts of the pathogen
- Safe to use, even on immunocompromised people
- Disadvantages
- Immunity is not prolonged, may need booster shots for ongoing immunity
- E.g., HPV virus (Human Papillomavirus)
COVID-19 Vaccines