FA16 Immunization Module’s Updates
Live and Inactive Vaccines
There are several classifications of vaccinations. Two of which are live and inactive vaccines. Live vaccines are derived from an attenuated form of the disease causing bacteria or virus. Live vaccines result in an immune response that is similar to a natural infection. In order for a live vaccine to be effective the organism must replicate. Failure to replicate does not elicit an immune response. Because of this, live vaccines must be stored in specific conditions that do not cause damage to the organism or impair its ability to replicate. In most cases, live vaccines do not pose a risk. However, uncontrolled replication can occur in immune deficient individuals resulting in severe or fatal reactions. There is also a possibility that the attenuated bacteria or virus could return to its pathogenic form.
Contrastingly, inactive vaccines are derived from deactivated bacterium or virus. Because the organism is deactivated, the bacteria or virus does not replicate. Inactive vaccines do not produce a natural immune response. Instead, the response to inactive vaccines is primarily humoral. In order for inactive vaccines to elicit a protective immune response, multiple doses of the vaccine must be administered. Levels of antibodies against the organism’s antigens decrease over time and require a boost (hence booster shots) to maintain immunity. Unlike live vaccines, inactive vaccines do not pose a threat to those that are immune deficient.
A chart containing major live and inactive vaccines are below. To see the full chart, use the link below.
http://www.cdc.gov/VACCINes/pubs/pinkbook/downloads/appendices/B/us-vaccines.pdf
Sources:
http://www.cdc.gov/VACCINes/pubs/pinkbook/downloads/appendices/B/us-vaccines.pdf
https://www.cdc.gov/vaccines/pubs/pinkbook/downloads/prinvac.pdf
Immunizations Basics PowerPoint
http://www.vaccines.gov/more_info/types/
New vaccines have recently begun to gain prominence in research known as DNA vaccines. These allow for DNA which produces viral proteins to be injected into a patient where they become included in the cells DNA to become transcribed and translated. The cells begin to produce viral proteins without transcribing enough for actual viruses to be produced. This means that the immune response is similar to live attenuated viruses without the dangers in patients with decreased or weak immune systems. Although there are yet to be any produced for vaccinations, the work is very promising. This may allow for us to produce vaccines that cross the boundaries you spoke about.
http://www.who.int/biologicals/areas/vaccines/dna/en/