Antimicrobial-resistant microbes, known as superbugs, are becoming an increasingly worrying global public health threat, according to the World Health Organization (WHO). In the United States alone, the Center for Disease Control (CDC) says that superbugs infect around 2 million people and kill 23,000 each year. As infections become more resistant to treatment, recommendations ranging from diligent hospital hygiene guidelines to limiting prescriptions of antimicrobials such as antibiotics have been suggested by experts to slow down the trend. Dr Bruce Gellin, an infectious disease and vaccine specialist, wrote an op-ed on STAT News explaining how vaccines present a solution to what he calls an "emerging crisis".

What are superbugs and how are they caused?

When microbes become resistant to the drugs used to treat them, they are deemed as superbugs. Superbugs don't just present themselves as the hospital acquired infections that usually make headlines like drug-resistant Clostridium difficile (C. difficile) or Methicillin-resistant Staphylococcus aureus (MRSA). They can also be in the form drug-resistant versions of infections that affect people outside of healthcare settings, such as antibiotic-resistant gonorrhoea, fluconazole-resistant Candida (a common cause of fungal infections) and antibiotic-resistant tuberculosis; with the latter two superbugs being considered "serious threats" by the CDC, according to the Scientific American blog.

Superbug strains of microbes are spread via the same routes of transmission as their standard counterparts, so people who are at risk of contracting normal strains of certain microbes could also be at risk of contracting the superbug versions. Antimicrobial resistance can occur naturally, but the overuse and misuse of antimicrobials in humans and livestock "accelerate the process," says the WHO.

How vaccines can help

Dr Gellin, who is also president of the Sabin Vaccine Institute, writes in his STAT News op-ed that because vaccines prevent some bacterial infections, the use of antimicrobials in treating those infections will be reduced and in turn, so will the risk of antimicrobial resistance.

He cites data supporting his stance, writing: "A study published in the Lancet led by Ramanan Laxminarayan of the Center for Disease Dynamics, Economics, and Policy found that if every child under 5 years old in the 75 countries studied received pneumococcal conjugate vaccines, the resulting reduction of pneumonia would avert 11.4 million days of antibiotic use each year."According to him, vaccination doesn't just help stop superbugs by preventing bacterial infections as a whole and reducing consequential antimicrobial use.

He writes that vaccines against viral infections also form a part of the equation when it comes to reducing antibiotic use, despite their being ineffective against viruses.

This is because antibiotics are sometimes misused by being used to treat the flu or flu-like viral infections. As cases of the flu decline due to vaccination, so will the potential for the antibiotics to be misused that way. Dr Gellin also adds that some viruses can cause secondary bacterial infections and that vaccinating against them also contributes reduced antibiotic use. Vaccines also benefit communities on a larger scale, as when disease circulation is limited, unvaccinated members of the community also benefit from protection, a concept called herd immunity, writes Dr Gellin.

It is true that vaccines form only a part of the solution to this global issue, and that experts are also working on solutions to actively fight superbugs, such as the creation of stronger antibiotics. But the experts agree that the prevention of infections is essential, and can avert a host implications from them; Dr Gellin writes: "It hardly matters how 'super' these bacteria are if we can prevent them from infecting people in the first place."