CD40LG and infection: Specifically, immunoglobulin M (IgM)levels rise quickly after infection or vaccination and drop shortlyafter recovery, while IgA and IgG levels take longer to increase anddecrease and are therefore more reliable to serve as indicators forimmunity against reinfection.26,27 Time-resolved screeningwith combinations of IgM and IgG binding antibody tests can providedetailed information about the seroconversion after infection or vaccination.Such tests only use selected proteins of the virus and can thereforebe used without the need for specialized biosafety facilities.