Within days of the first confirmed novel coronavirus case in the United States on 20 January, antivaccine activists were already hinting on Twitter that the virus was a scam—part of a plot to profit from an eventual vaccine.
Nearly half a year later, scientists around the world are rushing to create a COVID-19 vaccine. An approved product is still months, if not years, away and public health agencies have not yet mounted campaigns to promote it. But health communication experts say they need to start to lay the groundwork for acceptance now, because the flood of misinformation from antivaccine activists has surged.
Such activists have “kicked into overdrive,” says Neil Johnson, a physicist at George Washington University who studies the dynamics of antivaccine groups on social networks. He estimates that in recent months, 10% of the Facebook pages run by people asking questions about vaccines have already switched to antivaccine views.