FA16 Immunization Module’s Updates
Vaccinating the immunocompromised
Vaccinating individuals who are immunocompromised requires special precautions to reduce the likelihood of adverse side effects. The need to develop alternative vaccination methods for individuals suffering from infectious diseases is essential, especially when one considers that the incidence rate of HIV in the United States was 1.2 million in 2013 (CDC, 2014). The therapeutic regimens used in the treatment of HIV are sufficient for suppressing the viral load and maintaining CD4 T-Helper cell within range; however, not all patients respond to their medication. If a patient is responding poorly to their medication and their immune status unknowingly decreases, vaccination could prove disastrous to the immunocompromised individual. Immunocompromised patients who are vaccinated with inactivated vaccines have a minimal risk of suffering from any adverse side effects. An inactivated vaccine, according to Rubin et al. (2013), contains antigens that are unable to replicate and therefore, no infection will result from the vaccination. In contrast, immunocompromised patients who are given a live vaccine are at risk of developing a severe infection. A live vaccine is an attenuated form of the virus that does not replicate in a healthy individual, but can do so in an immunocompromised patient. Unfortunately, immunocompromised patients will not develop a proper immune response to eradicate the attenuated virus and there is a possibility that an opportunistic infection will occur. Even if the attenuated virus does not result in infection, there is a likelihood that the immune response will be insufficient for immunity to occur. As such, Rubin et al. (2013) reported that a healthcare practitioner must carefully consider the immunocompromised individual’s situation to determine if the use of a live vaccination is appropriate.
References
Centers for Disease Control and Prevention. (2014). Surveillance brief: terms, definitions, and calculations used in CDC HIV Surveillance publications. Retrieved September 28, 2016 from https://www.cdc.gov/hiv/pdf/prevention_ongoing_surveillance_terms.pdf
Rubin, L. G., Levin, M. J., Ljungman, P., Davies, E. G., Avery, R., Tomblyn, M., & Kang, I. (2013). 2013 IDSA clinical practice guideline for vaccination of the immunocompromised host. Clinical Infectious Diseases, cit684.
This is a great explanation for why immunocompromised individuals are not given live attenuated vaccines, but I have a different question. How do inactivated vaccines help immunocompromised individuals if their immune system is dysfunctional? In order to elicit a good immune response, there are many steps required: antigen phagocytosis, antigen processing, functional MHC, proper antigen display, successful immunological synapse, proper migration of many cell types, proper maturation and proliferation of cells, successful gene recombination events, and generation of functional memory cells. If all these must occur to gain immunity, how do immunocompromised individuals benefit from vaccine of any kind? My predication is that some other unrelated components of their immune system is compromised, but that malfunction does not interfere with the lengthy, complicated process of building immunity to an antigen.
Is there perhaps some sort of combination vaccination that could be used that included small doses of the live vaccine but also some dose of antibodies to go along with it to perhaps give the immuno-comprised patients a longer period of time for their decreased number of T cells? Or conversely, can we take out some T cells before chemo and inject them after? Essentially like bood-doping but with T cells.
Hi Jarod,
I thought your post was really interesting and the topic was not something I had considered prior to reading about it. I think that you're absolutely correct that we need to look into lower risk options on vaccinations for those who are immunosuppressed. This passage has really made me wonder how often people who are unknowingly infected with the early stages of HIV and the like respond to vaccinations, and How do Physicians screen for this to try to minimize the risk ?