Vaccines offer a potent armour against infectious diseases that once carried a heavy toll of mortality and morbidity, particularly among children. Gaps were already forming in that armour in the years before the COVID-19 pandemic. But amid stagnating vaccination rates, the pandemic acted like a shotgun, punching many more holes in humanity’s defences against preventable diseases such as measles.

The risks of allowing these infections to flourish are clear. Zimbabwe is currently working to contain a huge measles outbreak that claimed the lives of more than 750 children between April and October. And poliovirus has recently re-emerged in the United States after decades of successful elimination, prompting a state of emergency in New York.

The drop in vaccination rates is partly a direct consequence of the pandemic itself, which caused severe interruptions in public-health services and diverted resources. But it isn’t simply a crisis of access to vaccines. The failures and inequities in the global public-health response, coupled with politicization of the pandemic, have also undermined confidence in the institutions and people that coordinate and conduct immunization efforts.

Read more at Nature