title: [Comparison of specific immune responses to duck hepatitis B virus in infected, immune, and uninfected ducks].
abstract: OBJECTIVE
  To explore the factor in determining whether hepadnavirus infection is cleared or becomes chronic.
  
  
  METHODS
  Experimental groups were established by inoculation with duck hepatitis B virus (DHBV) at different age and schedule. The kinetics of virus replication and the humoral and cell mediated immune response (CMI) by ducks acutely and chronically infected with, or immune to DHBV infection was measured.
  
  
  RESULTS
  Infection of the adolescent animals with DHBV led to a transient viremia. The levels of anti-DHBs and anti-DHBc were higher in acutely infected group than in chronically infected group (P<0.05), but lower than in immune group (P<0.01). CMI analysis showed the response to DHBsAg and DHBcAg by peripheral blood mononuclear cells from acutely infected ducks (10 day pi) was stronger than that from chronically infected ones (P<0.05); however, the level of the response reduced over a period of 5 weeks. There were no differences regarding CMI response in acutely infected or immune ducks.
  
  
  CONCLUSIONS
  The immune response especially antigen -specific immune response is the key factor in determining the outcome of the infection.
authors: Institute for Viral Hepatitis, Chongqing University of Medical Sciences, Chongqing 400010, China.
authors: N
authors: N
authors: Tang
authors: A
authors: A
authors: Huang
authors: S
authors: S
authors: Guo
authors: Z
authors: Z
authors: Qi
authors: D
authors: D
authors: Zhang
mesh_terms: D000818:Animals; D004372:Ducks; D018347:Hepadnaviridae Infections / Q000276:immunology*; D006510:Hepatitis B Antibodies / Q000097:blood; D015611:Hepatitis B Virus, Duck / Q000276:immunology*; D007111:Immunity, Cellular; D014779:Virus Replication
chemical_list: D006510:Hepatitis B Antibodies