Current treatment strategies for chronic hepatitis B virus (HBV) infection aim at long-term suppression of the viral replication since a cure remains elusive. Its clinical management therefore relies greatly on routine monitoring of serum HBV DNA levels using quantitative polymerase chain reaction (qPCR) assays. Designing a highly conserved oligonucleotide set for the qPCR assay can be challenging due to the high genetic heterogeneity of the virus. The ever-increasing number of HBV genomes deposited in the GenBank nucleotide database warrants a revisit to previous primer and probe designs. We examined primer and probe sets from 53 qPCR assays published in the past 2 decades for their coverage in 9864 complete HBV genomes retrieved from GenBank. Of all the 53 qPCR assays, only 17% achieved ≥80% coverage. About 40% of the 53 assays covered less than 20% of the 9864 genomes. In silico DNA thermodynamics analysis demonstrated reduced primer/probe binding affinity, which further increases the risk of viral load misdetection and underestimation for certain HBV variants. Taken together, there is a pressing need for improving available qPCR designs for the quantification of HBV DNA based on the updated genome data.

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