“In patients with chronic kidney disease (CKD), the frequency of HBV infection is low, but not negligible,” explains Fabrizio Fabrizi, MD. “In addition, recent data indicate that chronic HBV infection promotes the development of CKD in the adult general population, which often leads to chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Since survival and quality of life are improved in patients with CKD without HBV infection compared with HBV-infected individuals, it is imperative that patients with advanced CKD undergo HBV vaccination.” Dr. Fabrizi adds that patients with advanced CKD undergoing hemodialysis are especially prone to acquire bloodborne infections, such as HBV infection.
HBV Vaccination Safe & Effective for Patients With CKD
For a paper published in Nephrologia, Dr. Fabrizi and colleagues aimed to examine the effectiveness and safety of recombinant HBV vaccine for the general population and especially for patients with CKD. The study team performed a narrative review to assess the mechanisms of lower immunogenicity of HBV vaccine in the CKD population. “Patients with CKD have a suboptimal response to various vaccines, and it remains unclear how we boost the immune response of such patients to the HBV vaccine,” he says, noting that the pathophysiologic mechanisms responsible for the poor immunogenicity of HBV vaccine in patients with CKD are under active investigation.
Since they frequently serve as primary care providers for patients with advanced CKD, Dr. Fabrizi says it is crucial to convey to clinicians the importance of vaccinating this patient population. “Various HBV vaccines are available throughout the world and some recombinant, second-generation vaccines are licensed in the United States,” he says. “Clinicians should aim to conduct mass vaccinations in patients with advanced CKD.”
Recombinant adjuvanted (HBV-AS04) vaccines are very effective, and the immunization rates are very high, Dr. Fabrizi continues; however, HBV-AS04 vaccines are not currently available in the US. “Clinicians typically prefer therapy to prevention,” he explains. “This is a common attitude of clinicians worldwide, not only in the US, most likely because results offered by therapies are immediately tangible, unlike those offered by preventative measures such as vaccination. However, the current public interest in vaccination toward SARS-CoV-2 has been generating interest in vaccination in general, including those for HBV (Table).”
Current HBV Vaccine Is Time-Consuming & Laborious
HBV-AS04 demonstrated better seroprotection rates and durable immune response over extended follow-ups compared with licensed HBV vaccine in patients with CKD, write Dr. Fabrizi and colleagues. The seroprotection rates were 95% (97/102) and 82% (202/248) in pre-dialysis and dialysis patients, respectively, 1 month after completing the vaccine schedule with HBV-AS04. HBV-AS02 was superior to a licensed vaccine in regard to seroprotection rate (76.9% vs 37.6%).
The researchers suggest adjuvanted recombinant HBV-AS04 vaccine and post-vaccination testing of anti-hepatitis B surface (anti-HBs) antibody in patients with CKD. In addition, booster doses are recommended for patients whose anti-HBs titers fall below the seroprotection level (<10 IU/mL) during follow-up.
“In previous studies, multiple approaches to improve the response rate of patients with CKD to HBV vaccine have been reported,” says Dr. Fabrizi. “Although recombinant HBV vaccines are available and their use is strongly recommended for patients with CKD by several international guidelines, adherence to these recommendations is frequently suboptimal in the developed world, including the US.”
One reason for the suboptimal active immunization rate of patients with CKD toward HBV is that the current HBV vaccine is time-consuming and laborious, requiring four monthly intramuscular doses, Dr. Fabrizi notes. “We desperately need vaccines with shorter vaccination schedules, such as a two-dose schedule instead of a four-dose schedule,” he explains. “In addition, the long-term protection offered by HBV vaccine remains unclear, as the evidence in the medical and scientific literature on this topic is limited. Fortunately, additional studies are underway.”
