Immunization carried out by introducing into the body either a live pathogen (inoculation), or a dead or weakened (vaccination), has proven to be highly effective in the fight against infectious diseases. In areas with a high rate of their transport, it led to a significant reduction in the incidence of diseases such as diphtheria, measles, rubella, poliomyelitis and whooping cough. Smallpox has been eliminated largely due to immunization. These successes have led to significant improvements in public health and a significant reduction in early mortality, as well as hereditary and acquired defects. But the main concern of the health authorities is that many parents who have not heard of diseases such as diphtheria or poliomyelitis will not have enough motivation to immunize their children. The danger also increases because, after a generation of relative relief from such diseases, the population will decrease or disappear natural immunity, and the reappearance of these diseases can lead to mass epidemics.In the United States, immunization is maintained by legislation that prohibits admission of unvaccinated children to schools.
Pathogens carry surface markers called “antigens,” which cause the immune system to produce antibodies to fight against them (see above). Fortunately, infectious organisms can be modified in such a way that, no longer representing a danger to the person infected with them, they retain their antigens. If such modified microorganisms enter the body, the immune system reacts to them in the same way as normal virulent microorganisms, and produces protective antibodies.
Immunity can also be achieved in a passive manner. Antibodies produced as a result of infection in another person or animal can be introduced into a person suffering from the same infection. Antibodies are protein molecules, not cellular organisms, so they do not carry their antigens. Human immunoglobulin (gamma globulin) is derived from blood transfused from a donor and contains a significant set of antibodies to diseases that are widespread in the general population, including measles, epidemic parotitis, hepatitis A, rubella and chicken pox.Immunoglobulins can also be obtained selectively from donors who have had a particular disease. In this way, immunoglobulins can be obtained for more rare diseases such as tetanus, rabies and hepatitis B.
Active immunization is always preferable, but since it takes time to build the required levels of antibodies, passive immunization is often necessary to treat serious diseases. Often, both types are combined - passive immunization provides immediate cover while at the same time gradually building up the patient’s own antibodies. Every person, starting from infancy, should be immunized against diphtheria, whooping cough, tetanus, polio and measles, and also, as necessary, against other diseases. Vaccination against smallpox is no longer required and should not be given. HIV-positive people, whether they have symptoms or not, should be immunized against measles, mumps, rubella, polio, whooping cough, tetanus, diphtheria, typhoid fever, cholera and hepatitis B.