events; the total number of recipients is too small and the follow-up generally too short to detect rare or delayed serious adverse reactions.
Studies of the immunogenicity of the recombinant vaccine show that, by the third dose, over 95 percent of healthy children and adults have responded by producing antibody. Infants and older individuals produce less antibody than young children and adults, which is the usual case for many vaccines.
Guillain-Barré syndrome (GBS) is characterized by the rapid onset of flaccid motor weakness with depression of tendon reflexes and inflammatory demyelination of peripheral nerves. The diagnostic criteria for GBS spelled out in Chapter 3 are those used in this chapter, although the data available from case reports in the literature or in reports of adverse events are often sparse and do not fulfill all diagnostic criteria. The annual incidence of GBS appears to be approximately 1 per 100,000 for adults. The data are not definitive, but the annual incidence of GBS in children under age 5 years appears to be approximately the same. The annual incidence of GBS in children over age 5 years and teenagers appears to be lower. Chapter 3 contains a detailed discussion of GBS.
The association of GBS and swine influenza vaccine has been an impetus for scrutinizing all new vaccines for neurologic sequelae. This was, no doubt, the impetus for the postmarketing surveillance study of Shaw et al. (1988). In addition, hepatitis B virus infection itself may have, on occasion, triggered GBS (Berger et al., 1981; Marti-Masso et al., 1979; Ng et al., 1975; Niermeijer et al., 1975; Penner et al., 1982; Tabor, 1987; Tsukada et al., 1987).
Chapter 3 presents background information on the biologic plausibility of a causal relation between vaccines and demyelinating disease. The association with GBS has been reported from various countries and with various versions of both plasma-derived and recombinant hepatitis B vaccines. As already mentioned, GBS has on occasion been reported to occur following hepatitis B viral infection.