OCCURRENCE OF CHICKENPOX DURING PREGNANCY IN WOMEN SEROPOSITIVE FOR VARICELLA-ZOSTER VIRUS

In a group of 21 women counseled after exposure to chickenpox during p regnancy, 4 developed varicella despite initial studies showing that p reinfection sera were varicella-zoster virus (VZV)-seropositive by flu orescent anti-membrane antibody, latex agglutination, ELISA, and VZV g lycoprotein immunoblot assay. Further investigations showed that 2 of the 4 had low-titer (1/100), low-avidity, VZV-reactive IgG3 antibodies by ELISAs of preinfection sera. After chickenpox, these women develop ed primary-like serologic responses to VZV. Two women with high-titer (1/1600, 1/3200), high-avidity, IgG1 antibodies showed anamnestic sero logic responses after reinfection. The criteria of protective VZV immu nity remain ill-defined.