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An improved vaccine against pertussis is needed. Pertussis toxin (PT) is secreted from Bordetella pertussis, the organism that causes pertussis or whooping-cough, and is used as a component of a vaccine which contains killed microorganisms. The gene encoding the pertussis toxin has been identified, and peptides (building blocks of proteins) that code for regions of the subunits of the toxin have been synthesized. These peptides can potentially be used for a recombinant or synthetic vaccine, which would be safe because the intact bacteria would not be included. The toxic effects of PT can be inhibited by blocking one of the subunits of the toxin, known as S1. Antibodies made against the S1 subunit protected mice from infection with Bordetella pertussis. Further study with the peptides of the S1 subunit allowed the identification of sites on the subunit which are necessary to stimulate T cells and generate an immune response. These tests were conducted in mice, but other studies have shown that a similar peptide causes an immune response in human blood cells. Further research is necessary to make a synthetic peptide, which can be used as a human vaccine to induce immunity against pertussis. (Consumer Summary produced by Reliance Medical Information, Inc.)

Exposure to whooping cough, a serious infectious disease in children, has been difficult to evaluate in the past due to lack of reliable tests. Careful questioning of parents about the symptoms has been used, but occasionally the disease may be atypical and therefore may go unrecognized. Two new tests (using enzyme-linked immunosorbent assays, ELISA) have been developed which determine the presence, in children's blood, of antibodies which recognize two proteins from the whooping cough bacteria (Bordetella pertussis), one of which is shared by other Bordetella bacteria. Parents of 266 Swedish children (who generally are no longer vaccinated against whooping cough) were questioned as to the possible occurrence of the disease in the children, and antibodies against the Bordetella proteins were measured. About one-half of the children had antibodies to either or both proteins, and the prevalence of antibodies increased with age. Antibodies to the nonspecific protein, filamentous hemagglutinin (FHA), were more prevalent. The protein test results were compared to results using another method which measured neutralizing antibodies, and the two methods correlated well. Of the 91 children whose parents reported occurrence of whooping cough, 90 had antibodies to one or both proteins. In contrast, only 14 percent of 175 children without history of whooping cough had detectable antibodies to the specific protein, and 36 percent had antibodies to the nonspecific protein. The results show a good correlation between parental information and serum antibody measurements. Interestingly, the data suggest that 14 percent of the children had atypical cases of whooping cough. Follow-up of children in the study indicated that antibodies to Bordetella pertussis may be protective against the infection. (Consumer Summary produced by Reliance Medical Information, Inc.)

Study objectives: The incidence and prevalence of pertussis in adults have increased in recent years. It has been shown that previously immunized adults and adolescents are the main sources of [...]

A child who develops certain side effects after receiving a DTP (diphtheria, tetanus and pertussis) vaccination need not necessarily forgo the remaining shots in the vaccination series, according to new […]