Sex differences in hepatitis A virus infection in mice.

Male mice infected with hepatitis A virus (HAV) exhibit 2-3 times higher viral replication and more severe liver injury than females, regardless of age.

• Why it matters: Understanding sex differences in hepatitis A outcomes can clarify biological mechanisms behind epidemiological disparities and improve targeted interventions.
• What they did: Researchers challenged male and female Ifnar1-/- mice with HAV, measuring viral loads, liver injury markers, immune responses, and hormone effects, including ovariectomy and estradiol treatment.
• The result: Findings show females have a protective effect from estrogen, reducing viral loads and liver damage, independent of hepatocellular estrogen receptor signaling, highlighting sex hormones' role in disease severity.