Lecture on Mycobacterium Vaccine

Jul 20, 2024

Lecture Notes: Professor Angus' Lecture on Mycobacterium Vaccine

Introduction

  • Speaker: Professor Angus
  • Topic: Mycobacterium Vaccine and its potential applications against various infections and cancers

Mycobacterium Overview

  • Definition: "Mycobacterium" - Despite the term typically referring to fungus (MCO), these are bacterial organisms with colonies resembling fungus.
  • Development: These bacterial organisms are killed, transferred into an injection, showcasing remarkable properties against melanomas, other cancers, and infections.

Immune Response and Melanoma

  • Initial Study Focus: Investigating immune responses in melanoma patients.
  • Findings: Patients exhibited suppressed immune responses, particularly T-cell responses.

Collaboration and BCG Vaccine Development

  • Key Individuals: John Stanford, Graham Rook, and John Grange.
  • BCG Vaccine: Originally developed for TB vaccination by attenuating for life.
  • Alternative Approach: Team explored environmental mycobacteria from regions with low TB rates; discovered Mycobacterium vaccae (associated with cows).
  • Significance: Instead of attenuating the strain, they used heat killing and borate buffering, producing a potent immunogenic agent.

Application in Cancer Treatment

  • Heat-killed Mycobacterium: Worked to boost T-cell responses in melanoma patients without negative effects.
  • Extended Usage: Proved effective as a universal T-cell vaccine, reducing occurrences of flu and other infections in treated patients.
  • Commercial Development: Shift from M. vaccae to Mycobacterium obuense (OB) with enhanced quality control and efficacy.

Clinical Trials and Efficacy

  • Definitive Trials: Conducted in metastatic pancreatic cancer, showing significant survival benefits when combined with chemo.
  • Approval and Regulatory Challenges: Despite strong data, still awaiting approval for broader use.

Broader Implications and Research Insights

  • T-Cell Immunity: Critical in containing and controlling cancers (e.g., B-cell lymphomas, melanomas).
  • Immune Suppression by Tumors: Evidence in colorectal cancer; post-surgery observation showed immune response bounce-back linked to better patient survival.
  • Speculative Extensions: Enhancing T-cell responses could potentially reduce early-phase cancer development.

Challenges in Regulatory Approval

  • Regulatory Hurdles: Despite strong evidence, the vaccine faces delays in approval due to bureaucratic requirements for larger trials.
  • Ethical Considerations: Urgent need for treatments in terminal conditions often clashes with slow regulatory processes.

General Takeaways

  • Resistance to Simplistic Solutions: GB vaccine-induced immune responses correlate inversely with cancer control; high-tech approaches may introduce complications.
  • Innate and Adaptive Immunity: Heat-killed mycobacteria work naturally to enhance T-cell responses, unlike certain modern vaccines which may disrupt this balance.

Conclusion and Future Directions

  • Potential Uses: A broadened application in cancers and severe infections could revolutionize treatment approaches.
  • Call to Action: There's a need for awareness and possible public advocacy for approval and wider usage of the vaccine.

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