A vaccine is a biological preparation intended to improve an individual’s immunity to a specific illness or disease. Most vaccines are composed of weakened or killed forms of an agent that resembles a disease-causing microorganism. A typically safe version of the pathogen, which is unable to cause the disease, is then produced by the altered or inactivated state. Once the vaccine is administered into the blood stream, the agent is recognized as a foreign body, which then triggers the process of active immunity, which in turn builds up antibodies to fight this particular pathogen (Wisegeek). Vaccination is intended to provide protection so that if the body comes in contact with the same type of disease in the future, the immune system will already have memory antibodies to fight the disease before symptoms occur. Since the introduction of vaccines for illness causing pathogens, diseases such as measles, polio and the common flu have greatly decreased in occurrence. With that being said, not all vaccines have been proven to be safe or effective. One virus that does not yet have an effective preventative vaccine is the Human Immunodeficiency Virus (HIV).
HIV is a retrovirus that attacks the human immune system. Transmission of the virus can occur in many different ways; through contact of infected secretions of one person with the genital, oral, or rectal mucous membranes of another person. HIV can also be transmitted through blood and from mother to child during pregnancy, childbirth or through breast milk (Healthmagic, 2010). The virus is characterized by its two glycoproteins: gp120 and gp41. The larger of the two glycoroteins is gp120, this molecule is the primary site of attachment to CD4 receptors of the host cell and while also triggering inflammation when shed into the blood. Gp41 promotes fusion to a target cell while remaining on the cytoplasmic membrane.
HIV infects four types of cells: helper T cells, macrophages, smooth muscle cells and...
Please join StudyMode to read the full document