迄今 ,疫苗的研制仍以传统的方法进行 ,例如 ,细菌毒素用传统的化学方法脱毒。生物技术和分子生物学的发展使人们对几种细菌毒素的结构 -功能关系有了很好的认识。有赖于此 ,细菌毒素的遗传减毒成为可能。依此方法 ,已产生了遗传脱毒的百日咳毒素 ( PT)。这种分子在婴儿中有高度的免疫原性和效力 ,现已成为百日咳无细胞菌苗 ( Pa)的组分。相同的细菌毒素分子脱毒策略已应用于霍乱毒素 ( CT)和大肠杆菌不耐热肠毒素 ( L T)。当去除毒性的毒素突变体与几种抗原结合接种于粘膜部位时 ,突变体表现出高度的免疫原性和强烈的佐剂性。这些成功的结果表明 ,研制更强有力、更安全的疫苗是可行的 To date, the development of vaccines is still carried out by traditional methods. For example, bacterial toxins are detoxified by traditional chemical methods. The development of biotechnology and molecular biology has led to a good understanding of the structure-function relationships of several bacterial toxins. Thanks to this, genetic attenuation of bacterial toxins is possible. In this way, genetically detoxified pertussis toxin (PT) has been produced. This molecule is highly immunogenic and effective in infants and is now a component of the B. pertussis (Pa) vaccine. The same strategy of detoxification of bacterial toxin molecules has been applied to cholera toxin (CT) and Escherichia coli heat-labile enterotoxin (LT). Mutants exhibit a high degree of immunogenicity and strong adjuvant when detoxified toxin mutants are seeded onto mucosal sites in combination with several antigens. These successful results show that it is feasible to develop stronger and safer vaccines