Saar Kuzi
Alessandra Coutinho Fernandes
William Cope
Richard Tapping
Kashif Ahmad
Reda Sadki
Shubhra Kanti Karmaker Santu
Adam P Rusch
Elle Meisner
Nereyda Ochoa
Landon J. Kunzelman
James DotimasFA16 Immunization Module’s Updates
Live Versus Inactivated Vaccines
Vaccines are used in order to simulate the immune system and produce an immune response similar to the response that would be activated by an infection that occurred naturally. This means that a vaccine is working to develop adaptive immunity to a particular pathogen. The adaptive system can stimulate memory cells in order to protect against future infection.
The two basic kinds of vaccines are live attenuated vaccines and inactivated vaccines. Both types have advatages as well as disadvantages. Live attenuated vaccines are a living version of the microbe, but it has been weakened in order for it not to cause disease. These vaccines need to replicate within the patient they are administered to. They are the closest vaccine to the natural infection; therefore they often can produce lifelong immunity with as little as one or two doses. However, it is possible for the microbe in the vaccine to revert back to its disease-causing form.
Inactivated vaccines, on the other hand, involve growing the microbe in media and then killing it using methods such as heat, radiation, or chemicals. Because these microbes are not alive, they cannot replicate. Therefore, the complete dose of antigen is required during injection to the patient. These vaccines are usually considered much safer than live vaccines due to the fact the microbe cannot revert back to its disease-causing form. However, inactive vaccines usually produce a weaker immune response than live vaccines. Because of this, multiple doses are always required. This is an important issue to consider when administering these vaccines in areas of people with limited access to health care.
Sources:
http://www.vaccines.gov/more_info/types/
Principles of Vaccination Document from the CDC
@ Victoria Costello. I think this is very important factor when determining what type of vaccine will be suitable to the patients depending on their immune system and current medical condition. As I read through it, I was wondering about the mechanism and how the inactivated vaccine works on the immunocompromised patient and permanent immune deficiency patient. And if they would react similarly or provoke similar responses in the innate and adaptive immune system.
You brought up an important issue pertaining to live vaccines and that they could revert back to their original disease-causing form. It is a scary thing to think about. Do you want to risk giving yourself the disease and having life-long immunity, or take a safer vaccine yet require more doses and possibly have a weaker immune response. I did not think about access to health care before I read your last sentence. Again, that is something to consider and whether your patient would make it back for their next dose of vaccine.