Study Explores Limits of HBV Vaccination in Patients Treated for HCV

Ekram Wassim, MBChB, MPH, PhD

Patients with chronic hepatitis C virus (HCV) infection often have poor responses to hepatitis B virus (HBV) vaccination even if they have been treated for HCV and achieved sustained viral response (SVR), according to a new study.

The data offer new insights into the limitations of the HBV vaccine, and could help identify which patients are most likely to benefit from vaccination, and which patients might not.

More than 170 million people worldwide have HCV infection, and 400 million people are believed to be infected by HBV. It is not clear how many patients have both, though some studies have suggested that HCV coinfection in patients who are hepatitis B surface antigen (HBsAg)-positive is as high as 30%.That’s a significant public health problem, because patients with both infections face higher rates of cirrhosis and other liver damage, explained corresponding author Ekram Wassim, MBChB, MPH, PhD, of the High Institute of Public Health at Alexandria University, in Egypt, and colleagues.

Previous reports have suggested that the HBV vaccine is less effective in patients with HCV infection and in patients with isolated HBV core antibodies (HBcAb). The development of direct-acting antivirals (DAAs) has led to an effective cure for HCV, but it is not fully understood how treatment for HCV might affect responsiveness to HBV vaccination.

Current guidelines suggest that any patient prescribed DAAs for HCV infection should also be assessed for HBsAg, hepatitis B surface antibody (HBsAb), and HBcAb. HBV vaccination is recommended for any patient deemed susceptible to HBV infection. In Egypt, Wassim and colleagues said, all patients with HCV infection who achieve SVR are given a full series of HBV vaccination, regardless of their vaccination history, HBV immune status, or serological profile.

Given the apparent conflict between widespread use of HBV vaccination in patients with HCV and the questionable efficacy of the vaccine in such patients, Wassim and colleagues decided to take a closer look at vaccine responsiveness among patients treated for HCV.

The investigators recruited 118 patients with chronic HCV who took 12 weeks of DAAs and were evaluated for HBV serological markers. Of those, 98 patients received HBV vaccines.

Among the vaccinated, 57.1% responded to the vaccine, but only 5.1% achieved a seroprotective level of HBsAb titer. Among those with HBcAb, the response rate was just 5.6%, compared to 64.5% in patients without. A multivariate analysis suggested that advanced age, and presence of isolated HBcAb were linked with poor responses.

Wassim and colleagues noted that the idea that isolated HBcAb limits responsiveness to HBV vaccine is controversial. Their data supports the link, but it does not appear to be the only answer.

“Nevertheless, this cannot account on its own for the high rate of hyporesponsiveness to HBsAg, which rather may be caused by the longstanding HCV infection,” they wrote.

The authors noted that the findings suggest Egypt’s aggressive approach to HBV vaccination might not be cost-effective.

The paper analyzes 3 models of vaccination strategies. The most cost-effective model involved testing all HCV-treated individuals for HBcAb, and not offering HBV vaccines to those patients who are seropositive. Among seronegative patients, a second analysis would be performed to test for HBsAb. Those patients with protective HBsAb levels would also not be offered a vaccine. However, those who were seronegative on the second test would be offered a three-dose HBV vaccine regimen.

Wassim told HCP Live that public health officials in countries with high rates of HCV should take note of the findings. She noted that Egypt has made hepatitis eradication a national health priority.

“Our work should be considered by stakeholders who might change the policy based on the promising findings,” she said. “This will add to the success of the HCV control program launched in 2014.”

The study, “Effectiveness of hepatitis B vaccination in chronic HCV patients after successful generic direct acting antiviral therapy: significance of isolated hepatitis B core antibodies,” was published online in Tropical Medicine & International Health.