Inactivated Influenza Vaccines Reported Safe for Cancer Patients on Immune Checkpoint Inhibitors

A new study reported cancer patients receiving Immune Checkpoint Inhibitors (ICI) did not increase their risk of immune-related adverse events after receiving an inactivated influenza vaccine. 

This small, IRB-approved retrospective review of advanced cancer patients on ICIs published in the Clinical Infectious Disease on March 15, 2019, answered the question if the flu vaccine exacerbates immune events in ICI patients.

Importantly, there were no fatal adverse events reported among the ICI patient population, and the portion of patients who developed immune-related adverse events was lower than previous reports, these authors reported. 

During the 3 seasons, 370 patients met criteria for ICI and vaccination within 65 days. The most common underlying cancers were lung (46%) and melanoma (19%); 61% of patients received anti-PD-1 agent only. 

In the entire cohort, 20 percent experienced an Immune-Related Adverse Event (IRAE) of any grade, and the incidence of grade 3 or 4 toxicity was 8 percent. 

No grade 5 events occurred. 

In the subset of 170 patients newly treated with anti-PD-1 agents, overall IRAE rate was 18 percent, grade 3/4 events occurred in 7.6 percent. 

These researchers, Curtis R Chong, Vivian J Park, Bevin Cohen, Michael A Postow, Jedd D Wolchok, and Mini Kamboj, concluded this report saying ‘there were no increase in incidence or severity of IRAE was detected in patients on ICIs who received the inactivated influenza vaccine within 2 months of ICI.’ 

‘For newly treated patients on anti-PDI agents, IRAE rates were comparable to published clinical trials and did not vary with the order of administration.’ 

And, ‘routine seasonal flu vaccination is encouraged in patients on ICIs.’ 

The study was partly funded by the NIH/NCI Cancer Center.