With COVID-19 vaccination rolling out in Australia little more than a year after the novel coronavirus was declared a pandemic, one could be forgiven for thinking it’s unlikely there’ll be another ‘once-in-a-generation’ infectious diseases crisis any time soon.

However, in what might come as a rude shock to many, researchers from India and the UK are warning that a highly contagious and rapidly evolving ‘old’ bacterium deserves our attention: Corynebacterium diphtheriae.

Although sporadic outbreaks of diphtheria in unvaccinated or partially vaccinated communities in low- and middle-income countries is common, there has been a steady climb in cases globally.

In 2018, there were nearly 17,000 reported cases, more than double the yearly average of 8105 cases recorded in the preceding two decades.