Study on SARS-CoV-2 infection in middle-aged and elderly population infected with hepatitis virus: a cohort study in a rural area of northeast China.

Background: To investigate the symptoms, the level of antibody, the progression of liver disease after SARS-CoV-2 infection in middle-aged and elderly population infected with hepatitis virus. Methods: The study was based on a cohort of high-risk liver cancer and the participants was recruited in April 2023. Blood sample were collected and information was obtained through questionnaires. Data on reinfection was obtained by follow-up until July 31, 2023. The SARS-CoV-2-specific neutralizing antibody and IgG were measured. Results: A total of 599 participants infected with hepatitis virus were included and the mean age was 61.3 ± 7.4 years. The SARS-CoV-2 infection rate was 94.7%. Among the infected, 132 were asymptomatic, 435 were symptomatic, no severe cases occurred. Four months after infection, no difference was in liver function and aMAP score between the infected and uninfected. The infected had higher seropositivity rates of both antibodies than the uninfected (neutralizing antibody: uninfected: 93.7%, infected: 99.6%; IgG: uninfected: 59.4%, infected: 98.9%). The levels of both antibodies in the symptomatic were higher than those the asymptomatic and the uninfected (neutralizing antibody: uninfected: 0.75 AU/mL, asymptomatic: 15.46 AU/mL, symptomatic: 24.76 AU/mL; IgG: uninfected: 15.10 AU/mL, asymptomatic: 263.84 AU/mL, symptomatic: 291.83 AU/mL). By July 31, 2023, the incidence of reinfection was 17.5%. Conclusions: Although the infection rate of SARS-CoV-2 was high, no severe cases occurred. Omicron infection may not aggravate progression of hepatitis. Four months after infection, the population showed high positivity rate in neutralizing antibody and IgG. Monitoring of virus mutations and targeted prevention and care strategies is crucial for vulnerable populations.