Protective antibody levels among hepatitis B vaccinated dialysis patients in Malaysia

Abstract

Background: Vaccination has significantly reduced hepatitis B infection globally. While WHO currently does not recommend booster doses owing to the presence of immune memory, certain advisory bodies such as CDC however suggested booster doses to be given to vaccinated dialysis patients with anti-HBs level of <10 mIU/mL. Older literatures have found that anti-HBs level of >100 mIU/mL confers complete protection against HBV infection in this particular population as they relied on the circulating antibodies, hence the requirement of booster doses. Due to lacking of local data, our objective is to evaluate the presence of protective antibody levels in vaccinated dialysis patients in a tertiary hospital located in Selangor state; one of the states in Malaysia with high hepatitis B incidence. Methods and materials: This prospective study involved 95 adult Malaysian chronic kidney disease patients, either on haemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD) between January and December 2018. Vaccination history was obtained from the proforma given and only those who completed primary adult vaccination series or those who were born in year 1989 upwards of which the neonatal hepatitis B vaccination was introduced in Malaysia were included. They were tested for HBsAg, anti-HBs and anti-HBc assays; in which only both HBsAg- and anti-HBc-negative patients were included in our analysis. Anti-HBs level was grouped to non-immune (<10 mIU/mL), partial immune (10–100 mIU/mL) and full immune (≥100 mIU/mL). Results: Out of 95 patients, only 36.8% (n = 35) were vaccinated. All of them were HBsAg-negative but 8.6% (n = 3) were anti-HBc-positive, leaving a total of 32 patients for our analysis. This involved 15 HD patients and 17 CAPD patients which comprised 12 males and 20 females with age distribution between 21 to 79 years. Majority were Malay, 59.4% (n = 19), followed by Chinese, 28.1% (n = 9), Indian, 9.4% (n = 3) and others, 3.1% (n = 1). Out of these 32 patients, 43.8% (n = 14) were partial immune, followed by 34.3% (n = 11) non-immune and 21.9% (n = 7) full immune. Conclusion: A higher rate of non-immune and partial immune hepatitis B vaccinated dialysis patients was observed in our study. Booster requirement for such population should be determined further by expert authorities to ensure protection against infection.