Immunizations: Collaboration

Immunity and Vaccination

Immunity is a healthy protective response of the human body, with the potential to distinguish the body's own cells from the foreign. Therefore, immune response in a healthy body does not attack its own cells but reacts to and tries to destroy foreign or unknown cells or agents. Although some infectious agents, such as viruses like chicken pox, measles, or mumps and bacteria like pertussis or whooping cough, leave natural immunity with a person who develops the disease, some other infectious agents may cause a fatal (e.g., smallpox, rabies) or disabling (e.g., polio, HIV, human papillomavirus) outcome if contracted.

In addition to a naturally produced immunity, medicine offers an artificial way of stimulating the immune system—that is, vaccination—by introducing the agent causing disease in a safe form and amount to a human body with the purpose of stimulating production of an immune response and to protect the organism by preventing the development of a disease. Therefore, vaccination provides artificially stimulated immunity. Immunization or vaccination is strongly recommended to prevent potential fatality or permanent disability. According to the Centers for Disease Control and Prevention (CDC), vaccines are divided into two categories: (a) live (attenuated) and (b) inactivated. The first group—live, attenuated vaccines—could be both viral and bacterial. The second group—inactivated vaccines—are further divided into whole (viruses and bacteria) and fractional (protein based and polysaccharide based). A general rule guiding the effectiveness of vaccines is this—a vaccine that is closer or more similar to a disease-causing agent provides the better response from an immune system.

In addition to active immunity, which a person's immune system produces in reaction to a foreign disease-causing agent and usually leaves lifelong protection, passive immunity does not provide a lifelong immunity. After another human or animal organism produces an immune response, the antibodies are introduced to the human body in need. For example, the anti-rabies serum (produced by an animal) is given to those exposed to a rabies virus after being bitten by a rabid animal (humans are not generally vaccinated against rabies). Another type of passive immunity is transferred from a mother to a newborn baby, and it lasts usually a few months of the newborn's life. In addition, immune protection is provided to a breastfed baby via a mother's breast milk. After that initial safe period, infants and children start to develop their own immune protection. It usually happens as they come in contact with various infectious agents (i.e., antigens), either naturally by acquiring diseases or artificially via vaccines.

...