SELECTIVE UNRESPONSIVENESS TO HBSAG VACCINE IN NEWBORNS RELATED WITH AN IN-UTERO PASSAGE OF HEPATITIS-B VIRUS-DNA

Thirty four out of 158 (22%) newborns to mothers chronically infected by the hepatitis B virus (HBV) did not produce antibodies (Ab) to HBsA g I month after the last injection of the HBV vaccine supplemented wit h HBV specific immunoglobulins. At birth, HBV genome,uas detected by p olymerase chain reaction (PCR) in the peripheral blood mononuclear cel ls (PBMC) of a large majority (28 out of 34) of these non-responder ne wborns but never in the other newborns who responded to the HBsAg vacc ine. HBV genome was detected in serum, only in some cases (nine out of 34) and never in the absence of HBV DNA in PBMC. For nine out of 14 f ollowed newborns, the absence of response was transitory since anti-HB s Abs appeared after 15 months, without booster, while the HBV genome had disappeared. Unresponsiveness was specific to the HBV envelope pro tein since all late responders and 15-months-non-responders to the HBs Ag vaccine produced normal levels of Abs to the three poliovirus serot ypes, to tetanus toroid and to the pneumococcus polysaccharides, An in utero induced immune tolerance to low doses of HBsAg appears as the m ost plausible hypothesis to explain this unresponsiveness to HBV vacci ne. (C) 1997 Elsevier Science Ltd.