Transmitted and pretreatment drug resistance among 69 HIV-1 CRFs in China: the first systematic analysis

In recent years, an increasing number of HIV-1 circulating recombinant forms (CRFs) have been identified in China. This study presented the first systematic analysis of the molecular epidemiological characteristics and drug resistance mutations (DRMs) profiles of all 69 CRFs identified in China up to 2025, comprising 13 first-generation, 45 second-generation, 10 third-generation, and one fourth-generation CRF . Several CRFs exhibited moderate transmitted drug resistance (5-15%) and elevated pretreatment drug resistance (10.8-55.1%). Notably, V179D/E were prevalent across multiple CRFs and, in combination with other DRMs, may contribute to reduced susceptibility to non-nucleoside reverse transcriptase inhibitors (NNRTIs). These findings provided critical surveillance data on DRMs and baseline data for NNRTIs selection in China, underscoring the necessity of phenotypic validation in novel CRFs harbouring natural DRMs.