Clinicians can administer the influenza vaccine concurrently with cytotoxic chemotherapy or during the cytopenic period to patients with cancer receiving 3-week cytotoxic chemotherapy cycles, according to a study published in the journal Cancer.1

Because limited research has evaluated the optimal timing of influenza vaccination for patients receiving chemotherapy, researchers sought to compare the immunogenicity of an influenza vaccine administered concurrently with chemotherapy with that of a vaccine given within the cytopenic period during 3-week chemotherapy cycles.

For the study, researchers enrolled 97 patients with solid tumors undergoing scheduled 3-week cytotoxic chemotherapy. Of those, 61% had breast cancer and 30% had lung cancer. Participants were randomly assigned to receive the 2014-2015 seasonal influenza vaccine on day 1 or 11 of the chemotherapy cycle.

Investigators stratified patients by their age and previous influenza vaccination status, and measured antibody responses to influenza vaccine strains H1N1, H3N2, and B before and 21 to 28 days after vaccination.

Results showed that seroprotection rates after vaccination were not significantly different between the day 1 and day 11 groups (strain H1N1, 67% vs 75% [P =.403]; strain H3N2, 77% vs 80% [P =.772]; strain B, 21% vs 27% [P =.472]).

Researchers also found that seroconversion rates and postvaccination geometric mean titers were similar between the 2 groups; however, vaccine-related adverse events occurred significantly more frequently in patients who received the vaccine during the cytopenic period (32% vs 13%; P =.040).

The findings ultimately suggest that influenza vaccination can be performed on the first day of chemotherapy administration or during the cytopenic period.

Reference

1. Keam B, Kim MK, Choi Y, et al. Optimal timing of influenza vaccination during 3-week cytotoxic chemotherapy cycles. Cancer. 2016 Dec 20. doi: 10.1002/cncr.30468. [Epub ahead of print]