Key Information:  Ticks coexist with a variety of symbionts and commensal bacteria, forming an ecological unit known as the tick holobiont. This holobiont represents an additional level at which natural selection operates. The tick's hologenome, which includes both the host and microbiome genomes, functions in a complementary manner. Studies suggest that disturbances in tick-microbiota homeostasis, often caused by antibiotic treatments, reduce tick fitness and alter interactions between ticks and pathogens. The use of broad-spectrum antimicrobial compounds targeting multiple bacterial species complicates the establishment of direct causal relationships between specific changes in tick microbiota and alterations in tick physiology or pathogen colonization. Currently, the lack of precise tools to manipulate the tick microbiome hinders deeper mechanistic understanding.

Recently developed anti-tick microbiota vaccines target the microbiota of vector arthropods by immunizing vertebrate hosts against live keystone bacteria or their proteins. This approach not only targets tick endosymbionts but also has the potential to predictably reshape the structure of tick microbial communities by reducing the abundance of selected keystone bacteria or endosymbionts. These vaccines offer a promising strategy to manipulate the tick microbiome to combat ticks and the pathogens they transmit.