Hepatitis B virus (HBV) vaccination induces protective immunity in most individuals, but 5-15% remain non-responders or low responders. Host genetic factors, particularly single nucleotide polymorphisms (SNPs) in cytokine genes, significantly influence vaccine-induced immune responses. Interleukin-10 (IL-10) is a key immunoregulatory cytokine that modulates B cell differentiation and antibody production. Given its role in immune regulation, polymorphisms in the IL-10 gene may affect HBV vaccine responsiveness and contribute to inter-individual variation in protection. This study aimed to identify specific SNPs in the IL-10 gene associated with HBV vaccine response in vaccinated individuals and evaluate their potential as predictors of non-response. A case-control study was conducted among vaccinated participants categorized as responders and non-responders based on anti-HBs antibody titers. Genomic DNA was extracted from peripheral blood samples. Selected SNPs in the promoter and coding regions of the IL-10 gene were genotyped using PCR-RFLP or real-time PCR. Associations between genotypes, allele frequencies, and vaccine response were analyzed using logistic regression, adjusting for age, sex, and other relevant covariates. Hardy-Weinberg equilibrium and linkage disequilibrium among SNPs were also assessed. Several IL-10 SNPs showed significant differences in allele and genotype distribution between responders and non-responders. Notably, promoter polymorphisms at positions -1082A/G (rs1800896), -819C/T (rs1800871), and -592C/A (rs1800872) were associated with vaccine response. The G allele at rs1800896 and the T allele at rs1800871 correlated with lower anti-HBs antibody titers and a higher likelihood of non-response. Haplotype analysis revealed that the ATA haplotype was significantly associated with poor vaccine response.  Specific SNPs in the IL-10 gene are significantly associated with HBV vaccine responsiveness. These genetic markers may serve as predictors for identifying individuals at risk of non-response, supporting personalized vaccination strategies. Further validation in diverse populations and functional studies are needed to clarify the underlying mechanisms and translational potential.

Keywords: IL-10 gene, Single nucleotide polymorphism, SNP, Hepatitis B virus, HBV vaccine, Vaccine response, Immunogenetics, Anti-HBs antibody.