Adults in rural areas are more likely to refuse the coronavirus vaccine than their urban and suburban counterparts, signaling that the federal vaccination campaign still faces a problem convincing some people to get the shots.

The Kaiser Family Foundation reported that 21% of adults living in rural parts of the United States would “definitely not” get the coronavirus vaccine once it became available to them, compared with 13% of adults in suburban areas and 10% in urban areas. The proportion of rural residents who said in March that they definitely would not get the shots was also consistent with previous months’ polling results. Almost three-quarters of them identified as Republican or Republican-leaning, and roughly 4 in 10 identified as white evangelical Christians.