Immunosuppressive Drugs Affect Vaccine Response in Inflammatory Bowel Disease Patients

Inflammatory bowel disease patients receiving immunosuppressive therapy had decreased immunogenicity to at least 1 of the 3 strains in the trivalent flu vaccine.

According to a study of inflammatory bowel disease (IBD) patients conducted during the 2010-2011 flu season, immunosuppressive therapy was likely to affect immune response to flu virus strains found in trivalent vaccines.

The differences in immune response were apparent regardless of whether participants received monotherapy or combination therapy, suggest the results of a study published in the March 2014 edition of the Journal of Crohn’s and Colitis.

“The multivariate analysis data showed that each individual drug or their combination therapy were likely to independently affect the immune response to at least 1 of the 3 influenza vaccine strains,” the researchers wrote.

A univariate analysis revealed similar results, even after controlling for the effects of confounding conditions. In particular, that analysis found lower outcome ratios for seroprotection for the H1N1 strain in participants receiving azathioprine and 6-mercaptopurine, and lower outcomes ratios for seroprotection from H3N2 and influenza B for participants receiving infliximab.

Researchers collected serum samples prior to vaccination, 3 weeks after vaccination, and after the flu season ended, which was approximately 7 months after participants received vaccination. The trivalent flu vaccine administered to participants included inactivated versions of H1N1, H3N2, and influenza B virus strains.

Of the 91 participants in the study, researchers collected an initial serum sample from all participants, and the postvaccination and post—flu-season samples from 88 participants. Three participants were excluded from the postvaccination and post–flu-season tests because of a confirmed flu diagnosis.

The participants included 45 with a diagnosis of ulcerative colitis and 43 with a Crohn’s disease diagnosis. In the overall group, 74 participants’ IBD was in remission stage and 14 participants’ IBD was in active stage. Only 30 participants were not receiving immunosuppressive therapy, whereas 58 participants received some form of immunosuppressive therapy, including corticosteroids, tacrolimus, azathioprine and 6-mercaptopurine, and infliximab. Immunosuppressive therapy could be administered as monotherapy or as combination therapy.

Despite the lower outcomes ratios for certain flu strains, geometric mean for each virus in the trivalent flu vaccine rose for all participants following vaccination, as did the seroresponse proportion, which suggested that the vaccines produced an immune response in all participants, researchers noted.

When considering the geometric means by immunosuppressive therapy, the researchers noted increased means for influenza H3N2 and B in participants receiving corticosteroids. Participants in this group also exhibited increased seroprotection against H3N2, researchers added.

Meanwhile, participants receiving azathioprine and 6-mercaptopurine decreased geometric means for influenza H1N1, and participants receiving infliximab had decreased geometric means for H3N2. Participants in those 2 treatment arms showed decreased seroprotection for the H1N1 and H3N2 strains as well.

The researchers reported no serious side effects in any participants, and no significant difference in side effect frequency between participants receiving immunosuppressive therapy or no immunosuppressive therapy.

The study results suggest that IBD patients receiving immunosuppressive therapy may benefit from different vaccination protocols, such as dual vaccinations with booster doses, the researchers noted. Immune response to the inactivated pneumococcal vaccine is also inhibited in IBD patients receiving immunosuppressive therapy, and the inactivated version of the hepatitis B vaccine requires a booster dose, they noted.

“We are currently investigating the efficacy of a booster dose of the trivalent influenza vaccine in adult IBD patients undergoing immunosuppressive therapy,” the researchers wrote. “Furthermore, the development of personalized vaccination plans, according to prevaccination antibody titer, treatment drugs, and immunologic potential, is expected in the near future.”