Relative levels of virus and rE protein binding antibody in immune sera.

aThe end point binding titers are based on ELISAs performed with virus or recombinant E (rE) protein antigen and serial dilutions of immune serum. The end point titer was the reciprocal of the highest dilution that produced a signal 2 standard deviations above the signal for normal human sera.bThe amount of antibody that bound to rE protein relative to the virus was calculated using the following formula: (end point titer for rE antigen/end point titers for whole virus)X 100. When endpoint titers were calculated using a E protein cross reactive mouse MAb (4G2), similar end point titers were obtained for well coated with virus or recombinant E indicating both antigens had a similar number of accessible E molecules.