Editorial

Vaccines and anti-microbial resistance: a fascinating tango

There is a fascinating connection between vaccines and anti-microbial resistance (AMR); it relates to the dynamic interactions that they may exert on each other. Small changes in a vaccination strategy may generate a benefit or unwanted downward effects in AMR insurgence and spreading; on the other hand, strategies to tackle AMR cannot avoid encompassing vaccination campaigns. Furthermore, complexity is a common feature both for vaccination strategies and AMR.

This Special Focus is intended to update the topic of vaccines and AMR but containing complexity. The idea was to select a reduced number of papers that could summarize actual knowledge and perspectives on the role of existing and future vaccines in tackling AMR.

AMR is a silent pandemic that is estimated to cause around 1.3 million deaths annually globally, with close to 5 million deaths associated with AMR¹ and which is estimated to increase significantly up to 10 million annual deaths in 2050.² Such figures exceed deaths from cancer and diabetes combined, and they do not take into account the impact of being unable to safely perform high-risk medical procedures, such as complex surgery or chemotherapy.³

The global community should continue to put efforts together to tackle AMR by finding ways to harmonize meaningful interventions in the One Health perspective.⁴ To maintain the effectiveness of antibiotics over an extended period of time, we need to not only ensure appropriate use of antibiotics but as part of coordinated stewardship plan to maximize the impact of vaccination on AMR. Vaccines offer sustainable protection against AMR, as they are evolution-proof. Resistance among vaccines is less likely to evolve, and when it does, it is less harmful to human and animal health and well-being than drug resistance.⁵ A consistent contribution to AMR containment policies will be reached by: a) increasing vaccine uptake; b) developing new vaccines that address prioritized AMR relevant pathogens; and c) filling the gaps in evidence generation of the benefits produced by vaccination.

Further research should investigate how best to establish the value of vaccines for AMR and to guide decision-making around allocating resources to the development and delivery of vaccines.^6,7 In fact, some of the broader value elements relevant to vaccines are not (consistently) considered in Health Technology Assessment processes, including preventing AMR.⁸ Improved value assessment criteria, including the health and economic benefits of AMR-relevant vaccines, are needed for existing and new vaccines. The inclusion of AMR and antibiotic prescribing as a reportable outcome in vaccine clinical trials should be encouraged, as this would strengthen the evidence base for the use of vaccines to control AMR. Vaccines against respiratory syncytial virus (RSV) may represent a first experience in this field. In 2020, WHO selected the priority disease areas for which vaccines were critically needed and available evidence supported a favorable technical feasibility assessment and potential impact on AMR.⁹ RSV was defined as a very common respiratory tract infection that affects all ages even though most severe in early childhood. RSV was framed as an important driver of antibiotic use for undocumented respiratory illness globally and thus with a potential to reduce RSV-driven antibiotic use.⁹ Recently, two vaccines for RSV in adults were approved in USA¹⁰ and one in Europe.¹¹ The evaluation at the Country level and consequent recommendations of RSV vaccines are expected to acknowledge, recognize and emphasize their role in tackling AMR as stated by WHO.

Commitments from national governments in National AMR Action Plans and from relevant scientific societies would lead the way for AMR relevant interventions at Country level. In the case of Italy, where antibiotic resistance represents a consistent problem,¹² the under-revision National Immunization Plan¹³ and National AMR Containment Plan¹⁴ were connected on this topic, and both acknowledge vaccines and vaccinations as tools to counteract AMR. Furthermore, 19 Italian scientific societies endorsed a position paper where vaccines and vaccination strategies, together with access to new antibiotics and the appropriate use of the existing ones, are the three pillars for a common strategy of tackling AMR.¹⁵

New vaccines directed toward AMR relevant pathogens are difficult to be discovered and developed for a number of reasons. Nevertheless, new technologies for vaccine design and delivery are on the way. The first-ever vaccine specifically addressing Neisseria gonorrhoeae, a high priority among the WHO list of AMR relevant families of bacteria that pose the greatest threat to human health,¹⁶ is starting phase I/II development.¹⁷

All these topics are discussed across the papers of the Special Focus.

In summary, AMR is a threat not only to every aspect of modern medicine but also to global health security and economic growth. AMR is a complex problem driven by multiple, interrelated factors. It is an issue that can only be addressed through a holistic, collaborative and multi-sectorial approach. A compelling and growing evidence base shows that vaccines are an important complementary tool to reduce the threat of AMR. There is a need to fill the remaining gaps in the evidence base on the impact of vaccines on AMR, including the health economic case, and to establish their value as a complementary strategy in the fight against AMR. On the other hand, new vaccines for pathogens that pose a threat to human health, and especially for those resistant to antimicrobial medicines, are urgently needed.

Funding Statement

The author(s) reported that there is no funding associated with the work featured in this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Disclaimer

Federico Marchetti is a GSK Vaccines employee. His contribution to this edition is based on his expertise and does not reflect GSK’s position.