Role of Vaccines in the Fight Against Antimicrobial Resistance

An estimated 700,000 deaths occur annually as a result of antimicrobial resistance (AMR), and this number could increase to 10 million by 2050.¹ Various efforts are currently underway to address AMR. In 2016, multiple initiatives collectively earmarked approximately $500 million for the timely development of new antibiotics that act on resistant pathogens.² There has also been a focus on reducing the amount of antibiotics used in food-producing animals, as this type of consumption has been linked to increasing AMR in humans.

In addition to these endeavors, more attention should be placed on preventive measures that could reduce the need for antibiotics in the first place, such as improved sanitation practices and the use of vaccines, according to a paper published in 2017 in Vaccine.³ “While the role of vaccines in combatting antimicrobial resistance has been mentioned or considered in recent reports and plans on AMR, much less effort has been put into supporting the greater use of existing vaccines and the development of new ones to address AMR,” wrote the authors.

In 2016, the United Kingdom released a report and recommendations on AMR, in which they emphasized the overlooked value of vaccines as a part of the solution. They indicated that investment in the research and development of new drugs exceeds that for vaccines, and they stated that more effort is placed on treatment than prevention in the present model of global healthcare.^4,5

The authors of the 2017 paper pointed out that even if new classes of antibiotic are developed, resistance to them is likely inevitable. “Because AMR is intrinsic to antibiotic use, the only long term solution to AMR is preventing the infections that necessitate their use,” they noted. Vaccines “have been a key element in disease prevention globally for almost two centuries [and] should therefore be considered as key weapons in the fight against AMR.” The pneumococcal conjugate vaccine, for instance, has led to reductions in resistant organisms and antibiotic prescribing.³

Infectious Disease Advisor discussed the topic with Nina Shapiro, MD, director of pediatric otolaryngology and professor of head and neck surgery at the David Geffen School of Medicine at the University of California, Los Angeles, and author of the upcoming book, Hype: A Doctor’s Guide to Medical Myths, Exaggerated Claims and Bad Advice. She offered additional examples of how vaccines could potentially be used in combating AMR:

• First, there are illnesses such as gonorrhea that have become completely resistant to antibiotics. Vaccination to prevent gonorrhea would alleviate this issue of a potentially untreatable disease.
• Second, vaccination against viruses such as influenza would protect against the virus, which in turn would protect against potential secondary bacterial infections. This would also minimize development of AMR. Vaccination against viruses would also reduce inappropriate prescribing for viruses, including influenza.
• Third, vaccinations against bacteria such as pneumococcus, which is prevalent and associated with a great deal of intermediate or complete antimicrobial resistance, would be avoided with more widespread pneumococcal vaccination.

Dr Shapiro agrees that vaccine research warrants more attention in the coming years: “There has been a great deal of work in developing advanced antimicrobial therapy, but the area of concern is infection prevention.”

At a meeting held in London in the United Kingdom in 2017, vaccine experts and stakeholders concluded that clear evidence is needed to convince national and international healthcare policymakers, scientists, and donors to increase their investment in the distribution and development of vaccines as a tool in the fight against AMR.³ Vaccines that could reduce AMR and are now under development include those for Clostridium difficile, Staphylococcus aureus, Group B Streptococcus, and Enterobacteriaceae.¹

When the participants of the London meeting were asked to choose the organisms for which vaccines would most substantially affect AMR, and should thus be prioritized for research and development, the top 5 selections were tuberculosis, typhoid, influenza, respiratory syncytial virus, and gonorrhea. To accumulate the required evidence to elicit action in this area in general, there is a need for more work “both in clarifying methodologies for modeling the AMR impact of vaccines and in generating more data to populate the models,” attendees concurred.

Other steps should include:

• Incentives for researchers and manufacturers to develop vaccines, especially those with a potentially high impact on AMR;
• Consideration of vaccine projects in AMR initiatives, on the same level given to new drug proposals;
• Regular reviews of vaccine progress to increase awareness of the “vaccine AMR value” in the realm of AMR efforts; and
• Continued focus on reducing antibiotic use in livestock, including the increased use of vaccines.

For healthcare providers, the “top takeaway is that clinicians need to consider both viral and bacterial prevention as a mechanism to reduce AMR,” said Dr Shapiro. “Most are focused on treatment, but prevention is critical in reducing wider spread resistance.”

References

1. Jansen KU, Knirsch C, Anderson AS. The role of vaccines in preventing bacterial antimicrobial resistance. Nat Med. 2018;24(1):10-19.
2. Boston Consulting Group, Federal Ministry of Health. Breaking through the Wall: a call for concerted action on antibiotics research and development. Berlin: German Federal Ministry of Health; 2017. Accessed March 19, 2018.
3. Clift C, Salisbury DM. Enhancing the role of vaccines in combatting antimicrobial resistance. Vaccine. 2017;35(48 Pt B):6591-6593.
4. Review on Antimicrobial Resistance. Tackling drug-resistant infections globally: final report and recommendations. London: Review on Antimicrobial Resistance; 2016. Accessed March 19, 2018.
5. Review on Antimicrobial Resistance. Vaccines and alternative approaches: reducing our dependence on antimicrobials. London: Review on Antimicrobial Resistance; 2016. Accessed March 19, 2018.