Vaccines, Immunology & Public Health
The human immune system defends against pathogens through innate non-specific barriers (skin, phagocytes) and adaptive immunity mediated by B-lymphocytes (humoral antibody production) and T-lymphocytes (cell-mediated immunity). Edward Jenner developed the first successful vaccine in 1796 using cowpox virus to confer immunity against deadly smallpox. Modern immunization utilizes multiple platforms: inactivated vaccines (Covaxin, Salk polio), live-attenuated vaccines (BCG, MMR, Sabin oral polio), subunit vaccines (Hepatitis B), and mRNA vaccines (Pfizer-BioNTech, Moderna) encoding viral spike proteins. India's Universal Immunization Programme (UIP) and Mission Indradhanush ensure nationwide coverage against vaccine-preventable childhood diseases like diphtheria, pertussis, tetanus, polio, and measles.
Key Concepts & Examination Highlights
- Edward Jenner pioneered vaccination in 1796 by using cowpox material to induce active immunity against smallpox.
- Live-attenuated vaccines use a weakened form of the living germ, exemplified by the Bacillus Calmette-Guérin (BCG) vaccine for tuberculosis.
- The Government of India launched Mission Indradhanush in December 2014 to expand full immunization coverage for children and pregnant women.