Many vaccinations are consistently recommended for diseases, such as Hepatitis A, Influenza, Measles, Mumps, and others. But not all vaccinations are the same, nor does every vaccination only require one dosage. There are generally two types of vaccinations that both work towards the same goal of producing some sort of immunological memory so that we are less likely to get the disease in the future. The two main types that I will discuss are live vaccines and inactivated vaccines. There are a number of differences between live and inactivated vaccines, including the nature of the immune response, the dosage that is required to produce immunity, what types of individuals can receive a live vs. inactivate vaccine, and others (1).

Live vaccines include a weakened form of the virus or bacterium, with some live vaccines examples being cholera, polio, and rabies. An inactivated vaccine includes a whole inactivated organism or a purified component with examples including influenza and hepatitis A (2,3). With live vaccines, the body’s immune response is actually similar to that of being naturally infected with the disease you are vaccinating against. In contrast, inactivated vaccines produce a predominately humoral response that is not as powerful as the live vaccine response (1).

Additionally, inactivated vaccines generally take multiple doses (sometimes up to 5 dosages) to be completely effective. On the other hand, live vaccines usually establish immunity with one dose. Also, live vaccines should not be given to already immune compromised individuals, whereas inactivated vaccines can be (1).

Interestingly, live vaccines must replicate to be effective whereas the inactivated vaccines do not. In fact, inactivated vaccines cannot replicate. So the very reliance of functional live vaccine success is dependent on something that inactivated cannot accomplish at all.  With the live vaccines, there is a chance that an intense reaction could be possible after vaccination (1).

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1. Immunization Basics: PowerPoint Slides 2, 4, 13, 15.

2.  American Society of Health System Pharmacists, Inc., DynaMed [Internet]. Ipswich (MA): EBSCO Information Services. 1995 - . Record No. 356522, Hepatitis A VirusVaccine Inactivated; [updated 2016 Jan 20, cited place cited date here]; [about 27 screens]. Available from http://search.ebscohost.com.proxy.cc.uic.edu/login.aspx?direct=true&db=dnh&AN=356522&site=dynamed-live&scope=site. Registration and login required.

3. American Society of Health System Pharmacists, Inc., DynaMed [Internet]. Ipswich (MA): EBSCO Information Services. 1995 - . Record No. 356527, Influenza VirusVaccine Inactivated; [updated 2016 Jan 20, cited place cited date here]; [about 36 screens]. Available from http://search.ebscohost.com.proxy.cc.uic.edu/login.aspx?direct=true&db=dnh&AN=356527&site=dynamed-live&scope=site. Registration and login required.