Explainer: What is herd immunity and how do we achieve it?
The percentage of people who need to be immune in order to achieve herd immunity varies with each disease, according to the World Health Organization (WHO).
The Covid-19 pandemic has been defined by volatility and unpredictability.
Things have changed once again, predominantly as a result of the Delta variant, which is having an impact on our hope of exiting the pandemic through herd immunity.
