Preventive Medicines and Vaccines
Vaccinations or Immunization are an indivisible part of preventive medicine against microbial infections, like measles, diphtheria, tetanus, hepatitis, smallpox, polio etc. A vaccine is a biological preparation that provides dynamically acquired immunity to a particular disease. Immunization, adjournment of weakened, killed, or divided microorganisms or of antibodies or lymphocytes that is controlled primarily to anticipate disease.
A vaccine can confer dynamic immunity against a particular harmful agent by stimulating the immune system to attack the agent. Once invigorated by an Immunization, the antibody-producing cells, termed as B lymphocytes, stay sensitized and ready to react to the agent should it ever gain entry to the body. A vaccine may confer passive immunity by providing antibodies or lymphocytes already made by an animal or human donor. Immunizations are usually administered by injection (parenteral administration), but some are given orally. Vaccines applied to mucosal surfaces, such as those lining the gut or nasal passages, appear to invigorate a greater antibody response and may be the most effective route of administration.