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
Vaccinating Immunocompromised Patients
Recent studies suggest that an important factor in determining the effectiveness of vaccines in immunocompromised patients may rely on the timing of the vaccination with respect to chemotherapy.
One study compared the response towards an influenza vaccine to the timing of the administration of chemotherapy [1]. The quality of the vaccine response was analyzed by identifying seroconversion.
Seroconversion is the time in which a patient first develop antibodies in high enough levels that makes antibodies detectable. This study defined a positive humoral response if there was a four-fold or greater increase in antibody titer after vaccination. In healthy individuals, antibodies usually appear within one week of exposure to the vaccine. However, in immunocompromised individuals, seroconversion might not occur until the third week.
In the group of patients with HIV who received influenza immunization between their chemotherapy courses, 93% showed seroconversion. This was significantly higher when compared to patients who received influenza immunization at the time when they were administered chemotherapy. Only 50% of them showed seroconversion.
Therefore, these results indicate that humoral responses may possible by improved if influenza vaccines are given between chemotherapy courses rather than concurrently with chemotherapy courses. This recommendation is supported by another study whose results showed that immunocompromised individuals who received influenza vaccination within 7 days receiving chemotherapy had a very poor humoral response [2].
Sources:
[1] http://www.sciencedirect.com/science/article/pii/S1473309909701756#fig1
[2] http://www.nature.com/bjc/journal/v82/n7/pdf/6691088a.pdf
I think that Omar has a really valid point in his comment! going from a 93% seroconversion rate to 50 is a huge jump being caused by the chemotherapy sessions. Perhaps further studying of the mechanisms behind this kind of inhibition could be used in the treatment of autoimmune disorders such as myasthenia gravis or multiple sclerosis to stop the immune responses being self-directed?
I think that it is interesting that HIV patients had more success being immunized than someone being treated with chemotherapy. But, it makes sense that isotype switching is just a longer process because B cells numbers are unaffected in HIV but Helper T cells are less abundant. This accounts for the longer time for seroconversion in this patient population. However, success rates are significantly lower in those undergoing chemotherapy because both T cell and B cell populations are expected to be lower. Leading to less interaction and less seroconversion. It is probably wise to vaccinate a patient a week or two before chemotherapy treatments. @Omar Calderon
It is interesting to read about immunocompromised groups such as HIV patients having high seroconversion. However, it is also surprising that the data for the chemotherapy group of immunocompromised patients have a 50/50 response to the influenza vaccine. Perhaps trying to find what is allowing some patients to have a better response by looking at the degree of chemotherapy used and the specific cancers being treated could elucidate whether or not a vaccine would be helpful at the time.