GENEVA, Switzerland (CMC) — The World Health Organization (WHO) Thursday said that vaccines against 24 pathogens could reduce the number of antibiotics needed by a significant number supporting worldwide efforts to address antimicrobial resistance (AMR).

WHO said in a new report that the reduction could be as high as 22 per cent or 2.5 billion defined daily doses globally every year and that while some of these vaccines are already available but underused, others would need to be developed and brought to the market as soon as possible.

AMR occurs when bacteria, viruses, fungi, and parasites no longer respond to antimicrobial medicines, making people sicker and increasing the risk of illness, death and the spread of infections that are difficult to treat.

AMR is driven largely by the misuse and overuse of antimicrobials, yet, at the same time, many people around the world do not have access to essential antimicrobials. The WHO said each year, nearly five million deaths are associated with AMR globally.

Vaccines are an essential part of the response to reduce AMR as they prevent infections, reduce the use and overuse of antimicrobials, and slow the emergence and spread of drug-resistant pathogens.

The new report expands on a WHO study published in BMJ Global Health last year. It estimates that vaccines already in use against pneumococcus pneumonia, Haemophilus influenzae type B (Hib, a bacteria causing pneumonia and meningitis) and typhoid could avert up to 106,000 of the deaths associated with AMR each year.

WHO said an additional 543,000 deaths associated with AMR could be averted annually when new vaccines for tuberculosis (TB) and Klebsiella pneumoniae are developed and rolled out globally. While new TB vaccines are in clinical trials, one against Klebsiella pneumoniae is in early stage of development.

“Addressing antimicrobial resistance starts with preventing infections, and vaccines are among the most powerful tools for doing that,” said Dr Tedros Adhanom Ghebreyesus, WHO director-general.

“Prevention is better than cure, and increasing access to existing vaccines and developing new ones for critical diseases, like tuberculosis, is critical to saving lives and turning the tide on AMR,” he said.

The WHO said vaccinated people have fewer infections and are protected against potential complications from secondary infections that may need antimicrobial medicines or require admission to hospital.

The report analysed the impact of already licensed vaccines as well as vaccines in various stages of development.

It found that annually, vaccines against streptococcus pneumoniae could save 33 million antibiotic doses, if the Immunization Agenda 2030 target of 90 per cent of the world’s children were vaccinated, as well as older adults.

It also found that typhoid could save 45 million antibiotic doses, if their introduction was accelerated in high-burden countries and malaria caused by Plasmodium falciparum could save up to 25 million antibiotic doses, which are often misused to try to treat malaria;

The study found that tuberculosis (TB) could have the highest impact once they are developed, saving between 1.2 to 1.9 billion antibiotic doses — a significant portion of the 11.3 billion doses used annually against the diseases covered in this report.

The WHO said vaccines could significantly reduce the substantial economic costs of AMR, and that globally, the hospital costs of treating resistant pathogens evaluated in the report are estimated at US$730 billion each year.

If vaccines could be rolled out against all the evaluated pathogens, they could save a third of the hospital costs associated with AMR, the WHO said, noting that a comprehensive, people-centred approach applied across health systems is needed to prevent, diagnose and treat infections.

It said this approach recognises vaccination as core to preventing AMR and especially impactful when combined with other interventions.

At the 79th United Nations General Assembly High-Level Meeting on AMR last month, world leaders approved a political declaration committing to a clear set of targets and actions, including reducing the estimated 4.95 million human deaths associated with bacterial AMR annually by 10 per cent by 2030.