The bacterial pathogen Streptococcus pneumoniae is a major public health concern, being responsible for more than 1.5 million deaths annually through pneumonia, meningitis, and septicemia. Available vaccines target only a subset of serotypes, so vaccination is often accompanied by a rise in the frequency of nonvaccine serotypes. Epidemiological studies suggest that such a change in serotype frequencies is often coupled with an increase of antibiotic resistance among nonvaccine serotypes. Building on previous multilocus models for bacterial pathogen population structure, we have developed a theoretical framework incorporating variation of serotype and antibiotic resistance to examine how their associations may be affected by vaccination. Using this framework, we find that vaccination can result in a rapid increase in the frequency of preexisting resistant variants of nonvaccine serotypes due to the removal of competition from vaccine serotypes.

细菌性病原体肺炎链球菌是主要的公共卫生问题，每年因肺炎，脑膜炎和败血病导致150万人死亡。可用的疫苗仅针对血清型的一个子集，因此疫苗接种通常伴随着非疫苗血清型频率的增加。流行病学研究表明，血清型频率的这种变化通常与非疫苗血清型之间的抗生素耐药性增加有关。在以前的细菌病原体种群结构多基因座模型的基础上，我们已经开发了一种结合血清型和抗生素抗性变异的理论框架，以研究疫苗接种如何影响它们的关联。使用这个框架，