As coronavirus cases resurge across the country, many inoculated Americans are losing patience with vaccine holdouts who, they say, are neglecting a civic duty or clinging to conspiracy theories and misinformation even as new patients arrive in emergency rooms and the nation renews mask advisories.

The country seemed to be exiting the pandemic; barely a month ago, a sense of celebration was palpable. Now many of the vaccinated fear for their unvaccinated children and worry that they are at risk themselves for breakthrough infections. Rising case rates are upending plans for school and workplace reopenings, and threatening another wave of infections that may overwhelm hospitals in many communities.

“It’s like the sun has come up in the morning and everyone is arguing about it,” said Jim Taylor, 66, a retired civil servant in Baton Rouge, La., a state in which fewer than half of adults are fully vaccinated.