Fendrix vs Engerix-B: Which vaccine is more effective against HBV in patients with IBD?

Vaccination against hepatitis B virus (HBV) with single-dose Fendrix does not result in a higher response rate compared with double-dose Engerix-B in patients with inflammatory bowel disease (IBD), results of a study have shown, noting that a four-dose schedule is more effective than a three-dose regimen.

In addition, lower response rate is driven by older age and treatment with immunomodulators or antitumour necrosis factors (anti-TNF).

To compare the two vaccines against HBV in inflammatory bowel disease, the authors randomized 173 patients to receive either Engerix-B double dose (54 percent) or Fendrix single dose (46 percent) at months 0, 1, 2, and 6. They measured anti-HBs 2 months after the third and fourth doses and again at 6 and 12 months after the fourth dose. Response to vaccination was characterized by anti-HBs ≥100 IU/L.

Less than half of the patients (45 percent) responded after three doses and majority of them (71 percent) did after the fourth dose. The response rate after the fourth dose was 75 percent and 68 percent with Fendrix and Engerix-B, respectively (p=0.3).

Older age and treatment with steroids, immunomodulators, or anti-TNF correlated with impaired success or a lower probability of response, but the type of vaccine was not associated with the response.

Anti-HBs titre negativization occurred in 13 percent and 20 percent of patients after 6 and 12 months, respectively. Anti-HBs ≥100 IU/L after vaccination was the only factor associated with maintaining anti-HBs titres during follow-up.

“A high proportion of IBD patients with protective anti-HBs titres after vaccination loose them over time,” the authors said. “The risk of losing protective anti-HBs titres is increased in patients achieving anti-HBs <100 IU/L after the vaccination.”