Strategy For An Hiv Vaccine example essay topic

HIV vaccine is possible. When HIV was identified as the cause of AIDS in 1984, researchers famously predicted that a preventive vaccine was right around the corner. Of course, it turned out that the task was not so easy, as in the early days of the epidemic, very little was understood about the virus. Yet in the time since, we have learned much more. In fact, we know now more about HIV / AIDS than other diseases against which vaccines have been developed. Researchers are taking clues from the ways the body naturally responds, or fails to respond, to HIV.

For example, on average 10 years elapse from the time one is infected with HIV to when the virus has done enough damage to warrant AIDS diagnosis. This means that the immune system has some ability to control HIV, albeit temporarily, and the role of a vaccine will be to boost these defenses to where they can deliver a decisive blow. Additionally, there are rare individuals who exhibit an exceptional ability to tame the virus, and analysis of what is different about their immune systems is yielding ideas for vaccines. For example, some female sex workers have remained HIV uninfected for years, despite repeated sex without condoms. Researchers are building and testing vaccines designed to stimulate killer and other immune cells that are believed to be responsible for these women's upper hand against the virus. Already experimental vaccines against HIV, a close cousin of HIV that infects monkeys, have been shown to prevent AIDS.

What works in animals does not always translate into humans; still this is an exciting proof of concept. Why makes the development of a new vaccine so difficult Creation of new vaccine is never easy, the development of a vaccine to prevent HIV infection, or even, for that matter, to delay or temper the deva sting impact of AIDS has proven especially difficult. Any strategy for an HIV vaccine must take into account the astonishing variability of the virus. Hiv mutates rapidly as the infection spreads, and the virus can literally change the antigenic structures faster than the immune system. HIV infects helper T cells, the immune cells that orchestrate the immune response.

It is very difficult to design a vaccine that, to be effective, needs to activate the very cells that are infected by the virus. Researchers do not know what constitutes an effective immune response to HIV. It might be antibodies, activated immune cells, perhaps a third immune response, or a combination of immune responses. HIV can be transmitted as both free virus and in infected cells. This may mean that both arms of the immune system may need to be stimulated.

Researchers lack an ideal animal model for AIDS vaccine testing. How AIDS Vaccines Are Developed To design a vaccine to prevent AIDS, researchers must start with an idea or strategy. All products selected for use as a potential AIDS vaccine go through a rigorous screening process. This process begins with an idea for attacking the virus based on vaccine theory and current knowledge of the disease and its mechanism of progression. Each candidate vaccine must undergo extensive pre-clinical evaluation in the laboratory, small animal models, and in non-human primates before it is tested in humans. The decision to move forward with human trials is based on pre-clinical results, availability of the product, and the anticipated promise of the approach based on related scientific findings.

In addition, before a vaccine can be administered to human subjects it must first undergo review by the FDA and Institutional Review Boards at each clinical site. Vaccine Types Strategies For Antibody Response Vaccine Whole-organism This strategy includes inactivating or attenuating whole bacteria and other pathogen is is still considered the most effective ways to make antibody-inducing vaccines. However, this approach does have drawbacks. With this vaccine there is always the chance that a badly prepared batch could cause disease rather than prevent it. Subunits an effective way to reap the benefits of whole organism vaccine, while at the same time avoiding their inherent danger. The surface structures of pathologens will be used to stimulate the production of the antibodies.

Anti-i dio Type This still experimental strategy provides a way to immunise again ts a pathogen without ever having to expose the vaccinated individual to any part of the pathogen itself. Strategies for cellular Response Vaccines Live-viruses In addition to being effective, live-virus vaccine can also be hazardous. Recombinant vectors To stimulate a cellular immune response - "killer" T cells-it is necessary for the protein of a pathogen to be processed within cells, which in turn means that a pathogen genes must active inside cells. However, it really isn't necessary to infect a cell with all of the pathogen's genes; only one will do. DNA vaccines Another strategy for introducing the genes of pathogens into cells is to use just the genes itself. Latest vaccines Bioption-IAVI AIDS vaccines The Bioption-IAVI AIDS vaccines will be constructed from Semliki Forest Virus (SFV) o it does not cause disease o include synthetic copies of a subset of HIV's genetic material o deliver HIV genetic material to human cells, in turn stimulating the immune system to develop defenses against the virus. o In laboratory tests, SFV-based AIDS vaccines have shown great promise for safely and effectively inducing anti-HIV immune responses Adis vax vaccine This is the only vaccine ever to get through Phase trials How Vaccines Work Vaccines are designed to stimulate the immune system to protect against microgranisms such as viruses.

When a foreign substance invades the body, the immune system activates certain cells to destroy the invader. This activation of the immune system involves two main types of cells: B cells and T cells. B cells make antibodies, molecules that attach to and neutralize viruses floating free in the bloodstream, thereby preventing the viruses from infecting other cells. T cells can be helper cells or killer cells. Helper T cells organize the immune response. Killer T cells (known as C TLs) attack cells infected by viruses.

Microorganisms such as viruses contain many molecules that are seen as foreign to the body. These different molecular shapes are called antigens, or epitopes. The B cells and T cells are activated by recognizing these antigens. Each individual T cell or B cell will only recognize and respond to its individual "destiny antigen". Once a T cell or B cell is activated by its destiny antigen, the B or T cell clones itself, making many duplicate copies of itself.

Some of these cloned T cells attack and destroy cells infected by the invading virus. Other cloned B or T cells remain in the body as memory cells. If the body is re-invaded by the virus in the future, the memory cells will be reactivated and respond faster and more powerfully to destroy the virus. This is the principle behind vaccines, such as the vaccinations we received in childhood against measles or mumps.