Passive immunization procedure

Two immunization procedures designed to enhance the immune response to multiple antigen mixtures have been reported recently. The cascade immunization technique (20) utilized in vitro depletion of E. coli proteins (ECPs) which had previously elicited an antibody response. The removal of these dominant immunogens from the mixture was accomplished by immunoabsorption with antibodies obtained from an earlier antiserum. The passive immunization procedure (21) relied on in vivo blocking of strong immunogens by the concurrent administration of early antiserum obtained previously. This latter report demonstrated the presence of an apparently poorly immunogenic ECP to which a humoral response could only be elicited by this passive procedure. 

A second group underwent the passive immunization procedure. The protocol was similar to the conventional immunization procedure except injections of antigen also included a concurrent intravenous injection of 0.5 ml of serum obtained from the same individual rabbit seven days earlier. 

Figure 4. Separation and detection of ECPs by two dimensional gel electrophoresis. A Silver stained. B Immunoblot with conventional procedure day 112 antisera. C Immuunoblot with cascade procedure day 112 antisera. D Immunoblot with passive immunization procedure day 112 antisera. Exposure time was 24 hours. Reproduced with permission from Ref. 24. Copyright 1989 The Humana Press Inc.

Antenatal hepatitis B screening for all pregnant women followed by active and passive immunization of all infants bom to HBsAg positive mothers is recommended. This procedure has a success rate of 90-97% and also provides long-lasting immunity, as mentioned by Lok 2002 and Marion et al. 1994. 

Immunization is either passive or active. In passive immunization, biotech-nologically constructed antibodies are raised as in animals the same as for antibody-based diagnostics, and then injected into human beings. This procedure is expensive and so is limited to life-threatening situations when the infected patient has not enough time to produce his or her own antibodies naturally. Ideally the antibodies must be humanized by protein engineering, namely made to look human, or else they are likely to be attacked by the body as alien animal products. 

Early work (796) on T. taeniaeformis and T. pisiformis showed that the high degree of immunity developed against larvae of these species could be transmitted by passive transfer of immune serum. Results with other species, such as E. granulosus and T. solium have not been so successful and not as promising as procedures involving active immunisation (see below). 

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