The correct option is (d).
Explanation
Vaccination involves the administration of an antigenic material (a vaccine) to stimulate an individual's immune system to develop adaptive immunity to a pathogen. Vaccines are available for a wide spectrum of viral and bacterial diseases, playing a crucial role in public health and disease eradication.
Statement-wise Analysis
- 1. Cholera: Correct. Cholera is an acute diarrhoeal infection caused by the bacterium Vibrio cholerae. There are currently safe and effective oral cholera vaccines (OCV) available, which are often used in humanitarian crises or areas with high endemicity.
- 2. Tuberculosis: Correct. Tuberculosis (TB) is caused by Mycobacterium tuberculosis. The Bacille Calmette-Guérin (BCG) vaccine exists to prevent severe forms of TB (such as TB meningitis) in children and is a standard component of the Universal Immunization Programme in India.
- 3. Smallpox: Correct. Smallpox was a contagious disease caused by the variola virus. It holds the distinction of being the first human disease to be eradicated globally, a feat achieved in 1980 primarily through a massive worldwide vaccination campaign.
- 4. Hepatitis: Correct. Hepatitis refers to the inflammation of the liver, commonly caused by viral infections. Safe and effective vaccines are available for Hepatitis A and Hepatitis B. The Hepatitis B vaccine is widely administered to infants under national immunization schedules.
Key Takeaway: Vaccination is a proven method for preventing numerous infectious diseases, ranging from historical pandemics like Smallpox to current public health challenges such as Tuberculosis, Hepatitis, and Cholera.