(Bismarck, ND) — The phenomenon of vaccine hesitancy is threatening herd immunity from COVID-19 in western North Dakota. The state is a national leader in the vaccination movement, with more than a quarter of the population vaccinated by late March. Some who are skeptical about the vaccine are a challenge for the state’s efforts to achieve mass immunity. Doubts are also causing a slowdown in vaccination efforts. Some who are younger and healthy are rejecting the vaccines, believing they have a good chance against the virus.