Immunosuppression occurs across a spectrum and can be severe, mild, or anywhere in-between. The degree of immunosuppression is best determined by a physician. Suppression of the immune system can be a result of disease or medication. Examples of diseases that result in immunosuppression include leukemia, HIV, and lymphoma (though there are many others). As previously mentioned, drugs such as chemotherapy can also suppress the immune system.

The safety of administering vaccinations to immunosuppressed individuals is a complicated matter, but can first be approached by determining which types of vaccine pose health risks and which are safe. There are two main types of vaccines: 

1. Live attenuated vaccines are those that contain live, but modified disease-causing viruses and bacteria. Due to the modifications, the microorganism is weakened, but still able to replicate. Live attenuated vaccines do not cause illness.
2. Inactivated vaccines are those that contain dead, disease-causing bacteria or viruses. The microorganisms in inactivated vaccines are unable to replicate and do not cause illness.

Inactivated vaccines (see table 1 for examples) are generally considered safe for all degrees of immunosuppressed persons. This is primarily due to the fact that the viruses and bacteria cannot replicate. Thus, it is recommended that immunosuppressed patients receive inactivated vaccinations as a healthy individual would. Some vaccines are particularly recommended for those with immunosuppression because it is a risk factor for many vaccine-preventable diseases (ie. influenza, hepatitis B) However, the efficacy of the vaccination may be decreased due to the inability of the immune system to bolster a response.

Live vaccinations (see Table 1 for examples), however, are more complicated. For those that are severely immunosuppressed, live vaccinations are not recommended.  This is primarily because, as mentioned, the bacteria or viruses are still able to replicate in live vaccinations. In a person with severe immunosuppression, the immune system is unable to appropriately handle the bacteria or virus. In some cases, live vaccinations may be recommended by a physician. These situations require a risk-benefit analysis and are usually determined by the degree of immunosuppression and the likelihood of exposure to a vaccine-preventable disease.

In summary, immunosuppression occurs with varying degrees of severity. Inactivated vaccines are generally considered safe for immunosuppressed individuals, whilst live vaccinations require a risk-benefit analysis and are generally not considered safe for severely immunosuppressed individuals.Immunosuppression occurs across a spectrum and can be severe, mild, or anywhere in-between. The degree of immunosuppression is best determined by a physician. Suppression of the immune system can be a result of disease or medication. Examples of diseases that result in immunosuppression include leukemia, HIV, and lymphoma (though there are many others). As previously mentioned, drugs such as chemotherapy can also suppress the immune system.

Resources

General Recommendations on Immunization. (2015). Retrieved September 27, 2016, from http://www.cdc.gov/vaccines/pubs/pinkbook/genrec.html

You Call The Shots. (2016). Retrieved September 27, 2016, from http://www.cdc.gov/vaccines/ed/youcalltheshots.html

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