Massive numbers of new COVID–19 infections, not vaccines, are the main driver of new coronavirus variants

It’s natural to wonder if highly effective COVID-19 vaccines are leading to the emergence of variants that evade the vaccine – like dark peppered moths evaded birds that hunted them. But with just under 40% of people in the world having received a dose of a vaccine – only 2% in low-income countries – and nearly a million new infections occurring globally every day, the emergence of new, more contagious variants, like delta, is being driven by uncontrolled transmission, not vaccines.