TNF and influenza: For influenza and pneumonia vaccines, some studies report a correlation between TNF inhibiting medications and reduced titers, some studies report no reduction in titers related to TNF inhibitor use, and some studies suggest that reduced titers could be due to co-administration of additional immunomodulating agents with the TNF inhibiting medication [8, 24, 25, 39–44], as is the case in many of our subjects.