In lieu of the development of novel antibiotics, prevention of bacterial infections via the use of vaccines might be a key alternative strategy available. Additionally, the use of vaccines and prevention or minimization of bacterial infections leads to decreased antibiotic consumption and is therefore likely to help with antibiotic resistance. Finally, by reducing or eliminating drug-resistant strains, vaccines could aid in decreasing antibiotic resistance. Vaccines designed could either be prophylactic or therapeutic, the latter being useful for preventing the infection from relapsing again and appearing to be more common in the context of tuberculosis. Vaccine can be composed of (i) live-attenuated bacterial cells, (ii) inactivated bacterial cells and, (iii) subunit vaccine which contains just enough material from bacterial cells to elicit an immune response and might include specific proteins or polysaccharides. Finally, inactivated toxins isolated from bacterial cells can also be used to design "toxoid" vaccines 239 examples include the DPT vaccine and tetanus vaccine among others. A report released by the WHO in 2021 provided details of >60 and >90 vaccines in clinical and preclinical development. The report was focused on identifying vaccines that have been designed for the bacterial strains that are listed in the 2017 WHO Bacterial Priority Pathogens List. The report indicates a lack of vaccines in development for E. faecium and Enterobacter spp. both of which are classified as high and critical priority in terms of requirement of new/novel antibiotics by the WHO.