Table 1.

Headlines and inoculation treatments for each of the experimental study conditions.

	HPV vaccine headlines	COVID-19 headlines	Inoculation
Base	Panel to Expand HPV Vaccine Recommendations	CDC Updates Recommendations on Mask Wearing
+Controversy	Controversy Erupts Over New HPV Vaccine Recommendations		…people…try to make health recommendations seem more controversial than they really are…. They create drama to draw attention away from the large amount of agreement…
+Controversy +Uncertainty	Advocates Cast Doubt on Scientific Evidence Behind New HPV Vaccine Recommendations as Controversy Erupts		…people…try to make health recommendations seem more controversial than they really are, saying that the science is more uncertain than it really is…. They create drama and exaggerate uncertainty to draw attention away from the large amount of scientific agreement…
+Controversy +Political	Political Pushback to New HPV Vaccine Recommendations as Controversy Erupts		…politicians…try to make health recommendations seem more controversial than they really are…. They create drama for political gain to draw attention away from the large amount of bipartisan agreement…
All Politicized Elements		Controversy and Political Pushback Over CDC Mask Wearing Recommendations in Light of Doubts About Scientific Evidence	…politicians or other people…try to make health recommendations seem more controversial than they really are, saying that the science is more uncertain than it really is or that there is more division between Republicans and Democrats than there really is…. They create drama and exaggerate uncertainty to draw attention away from the large amount of scientific and bipartisan agreement…

Note: News article treatment language varied between the two topics. Each of the politicized conditions added additional language (in addition to the headline changes listed in the table) to the base information to help emphasize the particular treatment which included discussion of heated debate and disagreement and a quote.