The Grand Finale of Blogs: Vaccines

Moment of silence for the effort, creativity, research, and time put into these beautiful blogs we write every week. To finish it off, we are going to talk about vaccines. Starting with how they approved and then discussing a vaccine that could be the next big breakthrough in medicine: an HIV vaccine. There are 6 major steps in the process of vaccine approval and I will be giving a brief description of each to help my readers better understand the process and hopefully it helps them be more aware of how important and safe vaccination is! To read more detailed information on the topic I would visit historyofvaccines.org!

• Exploratory stage: This is the basic research stage in which the scientists are pursuing what kinds of vaccine they want to create; whether it be VLP, conjugate, etc.
• Pre-clinical stage: This stage is where the initial testing on either human cell cultures or animals occurs. Checking desired dosage for further testing and observing adverse effects is the most important part of this stage. They may also test a early stage vaccine on animals and then attempt to infect them with the target pathogen.
• Clinical stage: A sponsor has submitted an application for a new drug to the FDA and has been approved for the next phases of testing.
  • Stage I: The first human subjects are tested on here. Normally not the target age initially but may work towards it throughout this stage. The vaccine is given to a small number of people and normally they know whether it is a placebo or not. Some researchers may also choose specific candidates as challengers and infect them with either a live or attenuated version of the pathogen. The goal is the monitor the immune response.
  • Stage II: A larger test group is used here since the stage I trial went well. This stage is more specific to individuals who may be more susceptible as well as confining the specific parts about the vaccine such as proposed doses and method of delivery.
  • Stage III: The testing pool is largely expanded in this stage. The vaccine is randomized and double-blinded against a placebo. Vaccine safety and efficacy are the most important things being tested here.
• Once a vaccine has made it past these stages it moves forward for approval and licensure.

As you can see, it takes many years and many tests in order to approve the safety of a vaccine and its ability to prevent the pathogen. Now lets talk more specifically about HIV and the lack of a vaccine against this disease. Researches have been attempting a vaccine against HIV/AIDS since the 1980’s. With variability in the virus and the lack of ability to produce the desired immune response it is extremely difficult to create a specific vaccine for this disease. The immune response that most researchers believe is the most desired requires activation of both acquired immune responses: cell-mediated and humoral immunity (antibodies). In the early 2000’s a vaccine came close to passing the clinical stages of testing but did not have large enough decrease in infection rate to quantify the results for approval. Although there have been failed attempts at vaccine production against HIV, each failure provides more information for the path the the approvable vaccine.