Original antigenic sin in the influenza vaccination and its influence / 中华预防医学杂志

Original antigenic sin may exist in the influenza virus infection or vaccination, which possibly reduces the protective efficacy in repeated influenza vaccination. This paper reviews the literature on the original antigenic sin and its influence in influenza vaccination, and interprets the possible mechanism of this phenomenon from the three aspects of influenza virus structure, humoral immunity and cellular immunity. A large number of studies have shown that original antigen sin has a negative impact on influenza vaccination, but the evidence disproveing this phenomenon also exist, so multi-center large-scale clinical trials should be conducted to provide evidence-based basis for reaearching whether original antigen sin exists and its effects. in order to provide reference for the development and update of noval influenza vaccines and its formulation of immunization strategies.

Effects of original antigenic sin on the immune response to inactivated influenza A virus subtype ;H5N1 vaccine / 中华微生物学和免疫学杂志

Objective To investigate the effects of original antigenic sin caused by previous expo-sure to influenza A virus subtype H1N1 on the immune response to inactivated H5N1 vaccine. Methods In this study, the BALB/c mice were first infected with A/PR8 (H1N1) virus or immunized with inactivated vaccine to induce immune responses against the A/PR8 virus. Then they were injected once with inactivated H5N1 vaccine at dosages of 0. 01μg, 0. 1μg and 1μg, respectively. The levels of IgG and neutralizing an-tibodies in serum samples were detected after immunization. Four weeks after immunization, the mice were challenged with a lethal dose of H5N1 virus. Some indicators including the survival rate, body weight loss and residue virus titer in lung were recorded for further evaluation. Results The pre-existing anti-A/PR8 antibodies in mice didn′t alleviate the immune responses to inactivated H5N1 vaccine. Conclusion This study indicates that the original antigenic sin associated with the previous exposure to A/PR8 virus has no significant effect on the immune efficacy of H5N1 vaccine.

Original Antigenic Sin Response to RNA Viruses and Antiviral Immunity

The human immune system has evolved to fight against foreign pathogens. It plays a central role in the body's defense mechanism. However, the immune memory geared to fight off a previously recognized pathogen, tends to remember an original form of the pathogen when a variant form subsequently invades. This has been termed 'original antigenic sin'. This adverse immunological effect can alter vaccine effectiveness and sometimes cause enhanced pathogenicity or additional inflammatory responses, according to the type of pathogen and the circumstances of infection. Here we aim to give a simplified conceptual understanding of virus infection and original antigenic sin by comparing and contrasting the two examples of recurring infections such as influenza and dengue viruses in humans.

Original Antigenic Sin Response to RNA Viruses and Antiviral Immunity

The human immune system has evolved to fight against foreign pathogens. It plays a central role in the body's defense mechanism. However, the immune memory geared to fight off a previously recognized pathogen, tends to remember an original form of the pathogen when a variant form subsequently invades. This has been termed 'original antigenic sin'. This adverse immunological effect can alter vaccine effectiveness and sometimes cause enhanced pathogenicity or additional inflammatory responses, according to the type of pathogen and the circumstances of infection. Here we aim to give a simplified conceptual understanding of virus infection and original antigenic sin by comparing and contrasting the two examples of recurring infections such as influenza and dengue viruses in humans.