Immunogenicity of influenza vaccine in colorectal cancer patients.

Objective: Although influenza is regarded as a major cause of morbidity and mortality in immunocompromised patients, vaccine coverage remains poor. We evaluated the immunogenicity of influenza vaccines in colorectal cancer patients.

Methods: In this study, 40 colorectal cancer patients who received an influenza vaccine at the Korea Cancer Center Hospital during the 2009-2010 and 2010-2011 influenza seasons were analyzed. The blood samples were collected at prevaccination and 30 days post vaccination, and antibody titers were measured using the hemagglutination-inhibition tests.

Results: In the 2009-2011 season, the seroprotection rate for H1N1 (94.7%) was significantly higher than that for H3N2 (42.1%) and B (47.3%). The seroconversion rate was 52.6%, 26.3%, and 36.8% for H1N1, H3N2, and B, respectively. Fold increase of geometric mean titer (MFI) was 3.86, 1.49, and 3.33 for H1N1, H3N2, and B, respectively. In the 2010-2011 season, the seroprotection rate for H1N1 (57.1%) was significantly higher than that for H3N2 (52.4%) and B (38.1%). The seroconversion rate was 52.4%, 47.6% and 33.3% for H1N1, H3N2, and B, respectively. MFI was 12.29, 3.62 and 4.27 for H1N1, H3N2, and B, respectively.

Conclusions: Our study cohort showed an acceptable immune response to an influenza vaccine without significant adverse effects, supporting the recommendation for annual influenza vaccination in colorectal cancer patients.