If a patient is infected for the first time with an new antigen, the Ig likely produced is:

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When a patient is infected for the first time with a new antigen, the first antibody produced is IgM. This is because IgM is the first class of antibody produced by the body in response to an antigen. It is a pentamer structure that can bind to a variety of antigens with high avidity. It is also capable of agglutination, complement activation, and opsonization. After a few days, IgG starts to appear and takes over the immune response. When a patient is infected with a new antigen for the first time, the initial immune response is mediated by IgM antibodies, which are the first antibodies to be produced during the primary immune response. IgM antibodies are relatively large and are present on B cells and in circulation. They are effective at activating the complement system and can neutralize pathogens by agglutinating them. Over time, IgG antibodies are produced and these can also neutralize pathogens by binding to them and triggering phagocytosis by immune cells.

If a Patient Is Infected for the First Time with an New