A vaccine is a biological substance that stimulates the immune system to produce an immune response to a specific pathogen, helping the body become immune to that pathogen. The act of administering a vaccine to an individual to provide immunity against a particular disease is called vaccination.

Immunity is the body's ability to defend itself against harmful pathogens, such as bacteria, viruses, or foreign substances. It involves a complex system of cells and proteins that recognise and neutralise these invaders, providing protection from infections and diseases. Immunity can be acquired through natural exposure, vaccination, or passive transfer of antibodies.

Antibiotics are a class of drugs used to treat bacterial infections in humans and animals. They work by targeting specific processes or structures within bacterial cells, which can include interfering with cell wall synthesis, protein production, or DNA replication.

An antiseptic is a substance or chemical agent that is applied to living tissue, such as the skin or mucous membranes, to inhibit the growth and spread of microorganisms, particularly bacteria, viruses, and fungi. They are used to reduce the risk of infection and promote wound healing.

The serum is an antitoxin-rich blood preparation used against a specific disease. This is yellowish and obtained when a blood sample is allowed to clot (coagulation). The sample is then centrifuged to remove the clot and blood cells, and the resulting liquid supernatant is serum. It consists of 90% water with dissolved hormones, proteins, minerals, and carbon dioxide. The serum is injected into the person against the specific disease. The antibodies present in the serum neutralise the antigens.