The number of coronavirus cases in most states is still rising, ensuring that the U.S. has a long way to go in its fight against the Delta variant.

Why it matters: Hospitals across the country are filling up with coronavirus patients, and some are running out of available ICU beds. Until cases begin to drop, the health care system will continue to face a crisis, and Americans will continue to suffer preventable deaths.

By the numbers: The number of total cases in the U.S. rose by nearly 18% over the last week.

• One in five ICUs throughout the U.S. has at least 95% of beds occupied, the NYT reported earlier this week, and the situation in the South is particularly grim.

Between the lines: Cases rose most in the Upper Midwest, Washington state, West Virginia and Washington, D.C.

• Some of the states hit hardest by Delta early on, like Missouri, Arkansas and Louisiana, saw a plateau in cases, a hopeful sign that their caseloads could soon start to decline.
• But even if they do, it will take several weeks for hospitalizations to decline as well.
• Cases rose by 12.6% in Florida, which continues to set hospitalization records that exceed the levels reached before vaccines were widely available.

The big picture: The highly transmissible Delta variant has been dominant in the U.S. for more than a month now and is spreading easily through the unvaccinated population.

• New data suggests that breakthrough infections have become more common, either because the vaccines are less effective against Delta or because their protection wanes over time.
• But the vaccines' effectiveness against severe disease has held up. The vast majority of hospitalized coronavirus patients are unvaccinated, meaning Americans without their shots are bearing the brunt of this wave of the pandemic.

Yes, but: Cases are a more limited measure of the pandemic now than they were in previous waves.

• That's because mild or asymptomatic cases, particularly among the vaccinated, are likely slipping through the cracks.
• And cases among the vaccinated are less of a concern than those among the unvaccinated, as they're highly unlikely to result in severe outcomes.

What we're watching: The Delta wave will likely burn out eventually, but it's anyone's guess as to when.

• On the positive side, the spike in hospitalizations and deaths appears to have prompted a bump in U.S. vaccination rates, and more than half of the population has already received their shots.
• On the other hand, Americans burned out on social distancing, combined with schools full of unvaccinated children — many of whom aren't required to wear masks — could provide ample fuel for the virus to keep spreading for awhile.