The correct answer is Diphtheria, Pertussis, and Tetanus. Explanation & Key Takeaways: • The DPT vaccine provides immunity against three serious bacterial diseases: Diphtheria, Pertussis (whooping cough), and Tetanus. • This vaccine is a part of the Universal Immunisation Programme (UIP) in India, aimed at protecting children from life-threatening infections. • Diphtheria affects the throat and can lead to breathing issues, heart failure, or paralysis. • Pertussis, or whooping cough, causes severe coughing fits, making it hard for infants to breathe and leading to complications like pneumonia. • Tetanus, also known as "lockjaw," is a bacterial infection that causes painful muscle stiffness and spasms, often through wound contamination. Related Concepts: • The DPT vaccine is usually administered in multiple doses starting at 6 weeks of age, followed by booster doses as part of the immunization schedule. • In addition to the DPT vaccine, there are combination vaccines like the DTaP (Diphtheria, Tetanus, acellular Pertussis), which are less likely to cause side effects. • The vaccine works by stimulating the immune system to produce antibodies against the toxins produced by these bacteria, without causing the disease. • Side effects of the DPT vaccine are usually mild and may include fever, swelling at the injection site, or irritability. • Vaccination coverage has significantly reduced the prevalence of these diseases globally, making them rare in countries with robust immunization programs.