UNIT 1: Introduction & Branches of Biology

Vaccines and Biopharmaceuticals

Vaccines and Biopharmaceuticals

Biopharmaceuticals, also known as biologic medical products, are pharmaceutical drug products manufactured in, extracted from, or semi-synthesized from biological sources. Unlike chemically synthesized drugs, these are complex molecules produced through cutting-edge biotechnology, primarily recombinant DNA (rDNA) technology.

Classification of Vaccines by Technology

Vaccines are biological preparations that provide active acquired immunity to a specific infectious disease. They are categorized based on the method used to handle the pathogen or its components.

1. Whole-Pathogen Vaccines
  • Inactivated Vaccines: Consist of virus particles or bacteria that have been grown in culture and then killed using heat or formaldehyde. They cannot replicate but maintain the structure for immune recognition.
    • Examples: Covaxin (Bharat Biotech), Polio (IPV), Hepatitis A, Rabies.
  • Live-Attenuated Vaccines: Use a weakened form of the germ. They create a strong, long-lasting immune response but are usually avoided for immunocompromised individuals.
    • Examples: MMR (Measles, Mumps, Rubella), Varicella (Chickenpox), Yellow Fever, Oral Polio Vaccine (OPV).
2. Subunit, Polysaccharide, and Conjugate Vaccines

These use specific pieces of the germ—like its protein, sugar, or capsid—to trigger an immune response.

  • Recombinant Protein Vaccines: Produced by inserting the DNA encoding an antigen into bacterial or mammalian cells.
    • Example: Novavax (Covovax), Hepatitis B vaccine.
  • Toxoid Vaccines: Use a toxin (harmful product) made by the germ that causes a disease. They create immunity to the parts of the germ that cause a disease instead of the germ itself.
    • Example: Diphtheria, Tetanus.
3. Nucleic Acid Vaccines (The New Frontier)
  • mRNA Vaccines: Teach cells how to make a protein that triggers an immune response. The mRNA does not enter the cell nucleus or affect DNA.
    • Examples: Pfizer-BioNTech, Moderna (Spikevax), GEMCOVAC-19 (India’s first indigenous mRNA vaccine).
  • DNA Vaccines: Involve the direct injection of a plasmid containing the DNA sequence for the antigen.
    • Example: ZyCoV-D (Zydus Cadila) – The world’s first DNA vaccine for humans, administered needle-free.
4. Viral Vector Vaccines

These use a modified version of a different, harmless virus (the vector) to deliver important instructions to the cells.

  • Examples: Covishield (Oxford-AstraZeneca/SII) uses a chimpanzee adenovirus; Sputnik V (Russia).

Key Biopharmaceutical Categories

Biopharmaceuticals extend beyond vaccines to include various therapeutic agents derived from living organisms.

CategoryDescriptionExamples
Monoclonal Antibodies (mAbs)Laboratory-made proteins that mimic the immune system’s ability to fight off harmful pathogens.Trastuzumab (Cancer), Itolizumab (Psoriasis/COVID-19).
Recombinant ProteinsProteins produced via rDNA technology in host cells.Recombinant Insulin (Humulin), Growth Hormones.
CytokinesSignaling proteins that help regulate the immune system.Interferons (used for Hepatitis), Interleukins.
Gene TherapyTechnique that modifies a person’s genes to treat or cure disease.Luxturna (Retinal dystrophy), Zolgensma.
BiosimilarsBiologic products highly similar to an already approved “reference” biologic.Indian biosimilars for Adalimumab or Insulin Glargine.

India’s Regulatory Framework and Initiatives

India is often referred to as the “Pharmacy of the World,” particularly in the vaccine segment.

Regulatory Bodies
  • Central Drugs Standard Control Organization (CDSCO): The national regulatory body for cosmetics, pharmaceuticals, and medical devices.
  • Drug Controller General of India (DCGI): Heads the CDSCO and is responsible for approval of licenses of specified categories of drugs including blood products, IV fluids, and vaccines.
  • Department of Biotechnology (DBT): Functions under the Ministry of Science and Technology; promotes large-scale use of biotechnology in India.
  • RCGM (Review Committee on Genetic Manipulation): Functions under DBT to monitor safety-related aspects of recombinant DNA projects.
Major Schemes and Missions
  • Mission COVID Suraksha: Launched to accelerate the development and manufacture of indigenous COVID-19 vaccines.
  • Ind-CEPI: A mission to strengthen India’s epidemic preparedness through vaccine development, aligned with the global Coalition for Epidemic Preparedness Innovations.
  • National Biopharma Mission (NBM): An industry-academia collaborative mission titled “i3” (Innovate in India) for accelerating discovery research to early development for biopharmaceuticals.

Technical Facts for Prelims

The Central Dogma of Molecular Biology

Understanding vaccines requires knowing the flow of genetic information: DNA is transcribed into mRNA, which is then translated into Protein. DNA vaccines target the start of this chain, mRNA vaccines the middle, and subunit vaccines provide the end product (protein) directly.

Cold Chain Requirements

The stability of biopharmaceuticals is temperature-dependent.

  • Traditional Vaccines: Typically stored at 2°C to 8°C.
  • mRNA Vaccines: Often require ultra-low temperatures (-70°C) for long-term stability due to the fragility of the lipid nanoparticles (LNPs) used to coat the mRNA.
Adjuvants

Adjuvants are ingredients used in some vaccines that help create a stronger immune response in people receiving the vaccine. Aluminum salts (alum) are the most commonly used adjuvants in human vaccines.

Passive vs. Active Immunity
  • Active Immunity: Results when exposure to a disease organism triggers the immune system to produce antibodies (via infection or vaccination). Long-lasting.
  • Passive Immunity: Provided when a person is given antibodies rather than producing them through their own immune system (e.g., Monoclonal antibodies, convalescent plasma, or breast milk). Immediate but short-lived.
Last Modified: April 22, 2026

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