“Hepatitis B is a common viral infection with 2 billion people worldwide having evidence of prior or current infection, and it can present as an acute or chronic infection,” or with chronic sequelae, including cirrhosis and hepatocellular carcinoma, Alexandra Ritter said during the annual meeting of the Society for Pediatric Dermatology. A three-dose vaccination series is recommended beginning at birth, and in 2016, the Centers for Disease Control and Preventionthat 90.5% of U.S. children aged 19-35 months had completed the series.
While the vaccine series provides protection in healthy individuals more than 95% of the time, a decreased response has been noted in specific pediatric populations, including those with inflammatory and autoimmune diseases. “This is important to note and investigate further because a decreased vaccine response increases the risk for this high-risk population, and the use of boosters is currently debated,” said Ms. Ritter, who is a fourth-year student at the Medical University of South Carolina, Charleston.
To determine the percent of pediatric patients with inflammatory or autoimmune disease who lack evidence of immunity following the hepatitis B vaccine series, Ms. Ritter and colleagues Abigail Truitt and pediatric dermatologist, of MUSC, retrospectively reviewed the charts of 160 patients between the ages of 6 months and 21 years, who were diagnosed with an autoimmune or autoinflammatory disease, or inflammatory bowel disease (IBD), and had documented evidence of vaccination and prior to the start of immunosuppressive therapy.
Of the 160 patients, 100 (63%) had IBD, 34 (21%) had an autoimmune disease, 26 (16%) had an autoinflammatory disease, 89 (56%) were female, and their mean age was 15 years.
The researchers observed variation in the testing ordered between the three patient groups. Specifically, 88.2% of autoimmune patients had hepatitis B surface antigen () testing, compared with 96.15% of patients with an autoinflammatory disease and 67% of patients with IBD, while 76.47% of patients with an autoimmune disease had hepatitis B core antibody (anti-HBc) testing, compared with 88.46% of patients with an autoinflammatory disease and 31% of patients with IBD.
In addition, 82.35% of patients with an autoimmune disease had HBsAg testing, compared with 100% of patients with an autoinflammatory disease and 94% of patients with IBD.
Of the 148 patients who had HBsAg testing ordered and completed prior to starting an immunosuppressive drug, there was no statistically significant difference in the percent of patients showing evidence of an immune response to the hepatitis B vaccine (32.14% among patients with an autoimmune disease, 34.62% among patients with an autoinflammatory disease, and 31.91% among patients with IBD). Combined, 67.57% of tested negative for the hepatitis B surface antibody.
“Our study showed that the majority of these patients did not show serologic evidence of immunity despite being fully vaccinated,” Ms. Ritter said. “There was also variation in the testing ordered and a more standardized approach is needed in this high-risk population.” She acknowledged certain limitations of the study, including its retrospective design and lack of a control group.
“This brings us to our next question of whether this indicates a failure of the vaccine, or the way immunity is tested,” she continued. “The CDC and the European Consensus Group on Hepatitis B Immunity recommend a cutoff of greater than 10 mIU/mL. Those that achieve immunity are protected for up to 20 years due to immune memory, even if their antibody levels later drop. There have been rare cases of immunocompetent individuals having evidence of transient asymptomatic infections when antibody levels drop. The chronic disease has only been documented in infants born to positive mothers. In hemodialysis patients, however, clinically significant infections have been documented when antibody levels drop.”
The CDC only recommends postvaccination testing to infants born to positive mothers, health care workers at high risk, hemodialysis patients, people with HIV and other immunocompromised people, and needle-sharing partners of chronically infected people. This is completed 1-2 months following the third vaccine dose, and those with antibody levels less than 10 mIU/mL should be revaccinated. “As some groups do not respond to the vaccine series, alternative dosing and the intradermal vaccine have been studied and shown to be effective in certain groups,” she said.
When it comes to monitoring immunocompromised individuals and giving booster shots, however, there are conflicting recommendations. The CDC recommends yearly testing and booster shots when levels drop below 10 mIU/mL only in hemodialysis patients, while the European Consensus Group recommends testing every 6-12 months for immunocompromised individuals and boosters when their levels drop below 10 mIU/mL.
“The CDC has not yet determined if other immunocompromised individuals should receive a booster, with more research required, but studies have shown it to be effective,” Ms. Ritter said. Inlooking at evidence of immunity in children with connective tissue disease who were on immunosuppressive treatment, 50% had no evidence of protective antibodies, compared with 96% in the control group. “In that study, a booster shot was given, and protective antibody concentrations were found at follow-up,” she said.
The researchers reported having no financial disclosures.