Vaccines Are an AMR Intervention
Efforts to control antimicrobial resistance (AMR) often focus on developing new antibiotics, improving diagnostics, strengthening stewardship, and preventing transmission of resistant organisms. Vaccination belongs in the same discussion.
Vaccines can influence AMR before an antibiotic is ever prescribed. By preventing infection, they can reduce the number of people who require antimicrobial treatment, directly prevent disease caused by resistant pathogens, and limit opportunities for pathogens to replicate, diversify, and spread. Vaccines against viral infections can contribute as well by reducing inappropriate antibiotic prescribing and secondary bacterial infections that might otherwise require treatment.1–6
The distinction between infection prevention and resistance control is therefore less clear than it may first appear. An intervention that prevents infections also changes antibiotic demand and the conditions under which antimicrobial resistance develops and circulates.
Recent modeling suggests that effect could be substantial.
How Large Could the Impact Be?
In its 2024 assessment of the potential impact of vaccines on AMR and antibiotic use, the World Health Organization (WHO) examined 24 pathogens and 44 vaccines, including vaccines already available and others in development.7
TheWHO estimated that optimal use of existing vaccines, with coverage reaching 90%, could avert approximately 106,000 deaths associated with AMR each year, save 9.1 million disability-adjusted life years (DALYs), avoid $861 million in hospital costs and $5.9 billion in productivity losses, and reduce annual antibiotic consumption by 142 million defined daily doses (DDDs).7
The potential effect becomes larger when future vaccines are included. WHO estimated that optimal use of vaccines against 23 of the 24 pathogens evaluated could reduce antibiotic consumption by approximately 2.5 billion DDDs annually, or about 22%. Vaccines in late-stage development alone could potentially avert more than 100,000 deaths associated with AMR and reduce antibiotic consumption by approximately 1.9 billion DDDs each year.7,8
These estimates broaden the rationale for vaccine investment. The value of a vaccine directed against an AMR-relevant pathogen may extend beyond the cases of disease it prevents. Its impact can also include antibiotics that are never prescribed and resistant infections that therefore have fewer opportunities to emerge or circulate.
Why Vaccination Changes the Resistance Equation
Vaccines affect AMR through several related mechanisms.
The most direct is prevention of infection. If vaccination prevents disease caused by an antibiotic-resistant organism, it reduces the number of resistant infections requiring treatment. When vaccination also reduces colonization or transmission, protection can extend beyond vaccinated individuals by limiting circulation of the pathogen within a population.1–5
Vaccination can also reduce antibiotic consumption even when the vaccine does not target a bacterial pathogen. Antibiotics are frequently prescribed for respiratory illnesses caused by viruses, despite having no activity against viral infections. Viral illness can also create opportunities for secondary bacterial infections that do require antibiotic treatment. Preventing the original infection can therefore reduce both inappropriate and appropriate antibiotic use downstream.2,3
A third effect occurs at the level of pathogen evolution. Vaccines act before infection becomes established or severe, limiting the size and duration of pathogen populations within hosts and reducing opportunities for replication and genetic diversification. Vaccine-induced immune responses may also act against multiple antigens or epitopes rather than imposing the type of single selective pressure often associated with a targeted antimicrobial drug.4,9
Vaccine escape can occur, and vaccination can alter the prevalence of pathogen variants. Nonetheless, vaccines can place pathogens in a very different evolutionary environment from treatment administered after an infection has become established.9
For AMR strategy, the important point is not that vaccination makes resistance impossible. It is that preventing infections can reduce the number of occasions on which resistant organisms must be treated, transmitted, and selected.
Real-World Evidence Is Already Available
Several established vaccination programs illustrate these effects.
Pneumococcal vaccination provides one of the clearest examples. Conjugate vaccines against Streptococcus pneumoniae have reduced invasive pneumococcal disease and produced indirect effects among unvaccinated populations through reductions in bacterial circulation. Following vaccine introduction in the United States, resistance to multiple antibiotic classes also declined substantially. More recent pneumococcal vaccines covering additional serotypes could further reduce respiratory disease and the associated need for antibiotic prescriptions.1–3,5,6
Typhoid conjugate vaccines illustrate the more direct relationship between vaccination and drug-resistant disease. Vaccination against Salmonella Typhi has been used in settings where resistant typhoid poses a significant public-health threat, including Pakistan and Zimbabwe. Modeling cited by Gavi, the Vaccine Alliance, suggests that widespread use of typhoid conjugate vaccines across high-burden countries could avert millions of cases of multidrug-resistant typhoid over a decade.5
Influenza vaccination demonstrates a different pathway. Preventing viral respiratory infections can reduce secondary bacterial infections such as pneumonia and otitis media and can also reduce situations in which antibiotics might otherwise be prescribed unnecessarily.2,3 These effects are especially relevant because much outpatient antibiotic use is associated with respiratory disease.
The three examples illustrate why the AMR value of vaccination cannot be captured by a single mechanism. A vaccine may directly prevent resistant disease, reduce antibiotic consumption, interrupt transmission, or accomplish several of these goals at the same time.
The Next Opportunity Is the Vaccine Pipeline
Greater use of existing vaccines could produce significant benefits, but vaccine coverage alone cannot address pathogens for which effective vaccines do not yet exist.
The WHO and other groups have therefore begun examining vaccine development more explicitly through an AMR lens. Vaccine Value Profiles published in 2024 considered dozens of candidates targeting AMR-priority pathogens, with much of the development activity concentrated in organisms such as Mycobacterium tuberculosis and S. pneumoniae. At the same time, important gaps remained for several priority pathogens, including Pseudomonas aeruginosa and Acinetobacter baumannii.3,7
Tuberculosis demonstrates the potential scale of the opportunity. Drug-resistant tuberculosis remains a major treatment challenge, and modeling cited in the vaccine assessments suggested that even a partially effective vaccine capable of reducing progression to active disease could prevent large numbers of deaths from drug-resistant tuberculosis in countries carrying most of the global burden.3
Other targets present different scientific and development challenges. Efforts continue to develop vaccines against pathogens including Clostridioides difficile, Staphylococcus aureus, pathogenic Escherichia coli, Klebsiella pneumoniae, group B Streptococcus, Neisseria gonorrhoeae, and Shigella.3 Some of these pathogens have long histories of unsuccessful vaccine development, while others must be addressed in populations with specific safety or immunogenicity requirements.
Those difficulties make prioritization important. If the ability to reduce antibiotic use, resistant infections, and transmission is incorporated into assessments of vaccine value, AMR impact could become another factor guiding which targets receive scientific attention, financing, and development support.
Making Vaccination Part of AMR Strategy
Vaccines will not replace the need for new antimicrobials, better diagnostics, stewardship, surveillance, infection control, or improved access to appropriate treatment. They can, however, reduce the number of infections for which those tools are needed.
That makes vaccination relevant at several points along the AMR continuum. Greater uptake of existing vaccines can prevent infections today. New vaccines could address pathogens for which resistance has made treatment increasingly difficult. Viral vaccines can reduce antibiotic exposure even when bacteria are not their primary target.
The larger opportunity is conceptual. Vaccination is often categorized as infection prevention, while antibiotics and stewardship are treated as the principal tools for addressing antimicrobial resistance. The evidence suggests that these categories overlap.
Preventing infection changes antibiotic demand, pathogen transmission, and the evolutionary environment in which resistance develops. As a result, vaccine coverage, vaccine research and development, and the prioritization of new vaccine targets should be considered part of AMR strategy itself.
