Lecture Notes: Antibiotics, Antivirals, and Vaccines

Introduction

• Antibiotics, antivirals, and vaccines help the immune system.
• The immune system protects against pathogens (bacteria, viruses, fungi, protists, parasitic worms).

Immune System Basics

• First Line of Defense:
  • Skin: Barrier and contains helpful microbes.
  • Mucous membranes.
• Second Line of Defense:
  • Non-specific white blood cells (e.g., macrophages).
  • Inflammatory response.
• Third Line of Defense:
  • Specific immune response (lymphocytes: T cells and B cells).
  • T and B cells react to antigens (foreign molecules like pathogens).
  • Memory B and T cells "remember" pathogens for quicker response upon re-exposure.

Antibiotics

• Target bacteria specifically (e.g., strep throat, staph infections, pneumonia).
• Methods:
  • Destroy bacterial cell walls.
  • Block protein production.
• Forms: Pills, injections, IV.
• "Antibiotic" means "against life," not to be confused with antigens or antibodies.

Antibodies

• Proteins made by immune cells (B cells).
• Y-shaped and bind to pathogens to disable or mark them for destruction by macrophages.

Vaccines

• Expose body to inactive or weakened forms of pathogens.
• Stimulate immune response without causing disease.
• Create memory cells for future protection (immunity).
• Effective against bacteria and viruses.
• Role in eradicating certain diseases (e.g., smallpox).
• Herd immunity: Protects vulnerable populations (e.g., immunocompromised individuals, newborns, pregnant women).
  • Example: Rubella and its risks during pregnancy.

Antivirals

• Target viruses specifically.
• Forms: Pills, liquid, IV.
• Reduce severity of viral infections if given timely.
• Work by stopping virus replication without harming host cells (e.g., blocking specific proteins).

Challenges with Pathogen Mutation

• Pathogens can mutate and evolve, leading to antibiotic resistance and varying vaccine effectiveness.
• Example: Influenza virus changes frequently, requiring annual vaccine updates.
• Scientists strive to predict and counter these changes.

Conclusion

• Importance of staying informed and curious about antibiotics, antivirals, and vaccines.