Immunity is a special ability of the organism that allows it to resist various diseases by targeting and destroying foreign agents. Two types of immunity are usually defined – active and passive. Active immunity is the process of exposing the organism to a certain antigen that will trigger an immune response. Such a response can take days and even weeks to start up, but it has a very long-lasting effect. Active immunity can be acquired or natural. Artificially acquired immunity can be triggered by a vaccine, which contains a specific antigen. This vaccine will stimulate the initial response against that specific antigen without stimulating the symptoms of the illness.
Passive immunity can be divided into two types – artificial and natural. Artificial passive immunity is immunization through the injection of certain antibodies. Natural passive immunity develops during pregnancy. Some antibodies are passed from the mother to the fetus’s bloodstream through the placenta. As a result, the newborn baby has a natural protection for a couple of the first few weeks or even months, until this antibody loses its protecting power and disappears. Opposite to this, acquired passive immunity develops when the serum is obtained from immune individuals, accumulated, and immunoglobulin fraction is concentrated. After this procedure, the injection to the susceptible person is made. The four most widespread preparations of immunoglobulin that are used in modern medicine include: Human Hepatitis B, Human Rabies, Human Tetanus, and Human Varicella-Zoster.
To conclude, one type of immunity cannot be more effective than another, as they are complementary and help people to stay healthy or effectively fight with most diseases. The importance of both types of immunity is so great that the Centers for Disease Control and Prevention have called it one of the biggest achievements of healthcare in the 20th century (especially, the development of artificial immunization).