Hepacivirus hominis. Hepacivirus hominis

Vertical transmission is the major cause of pediatric HCV infection worldwide. To better understand the pathogenesis of hepatitis C during and after pregnancy and to provide insights into the risk factors and mechanisms involved in vertical HCV transmission, the evolutionary dynamics of HCV variant spectra and HCV‐specific neutralizing antibody responses were examined using high throughput sequencing and pseudoparticle‐based assays in pregnant women monoinfected with HCV (n = 17) or coinfected with HCV and HIV‐1 (n = 15). Overall, statistically significant associations were found between HCV quasispecies diversity, selective pressure exerted on the HCV E2 envelope protein, and neutralizing activity of maternal immunoglobulins. Women with low quasispecies diversity displayed significantly higher mean AST and ALT levels throughout pregnancy, but this difference was restricted to monoinfected participants. Low quasispecies diversity and inefficient neutralizing activity were also significantly associated with vertical transmission, but only in the monoinfected group. These results indicate that maternal neutralizing antibody responses play an important role in the prevention of vertical HCV transmission, but not in presence of coinfection with HIV‐1, and suggest that the mode/route of vertical HCV transmission differ between monoinfected and coinfected women. These findings could inform clinical management strategies for prevention of vertical HCV transmission.