Monday was another day that underscored the crosscurrents for the nation’s leaders as their efforts at a disciplined public health campaign collided yet again with the chaotic nature of the pandemic. Instead of a consistent message, the result was another dizzying jumble of news stories and divergent announcements.

In Louisiana, a state with one of the lowest vaccination rates, Gov. John Bel Edwards reinstated an indoor mask mandate, as did health officials in San Francisco and six other Bay Area counties. But in New York City, Mayor Bill de Blasio declined to do so, even though such a move would have been in line with C.D.C. guidelines.

The virus continued to scramble traditional politics. In left-leaning Chicago, city officials announced that more than 385,000 people had attended the four-day Lollapalooza music festival — and Mayor Lori Lightfoot defended it. In Washington, Senator Lindsey Graham, Republican of South Carolina and a longtime supporter of former President Donald J. Trump, announced that he had tested positive for the coronavirus, but said his symptoms had been mild, which he attributed to having received the vaccine…

Another administration official said Mr. Biden would address the nation later this week — the second time in less than a week — to reiterate and clarify his main takeaway points: The vaccines are safe and effective. The reason even vaccinated people have to mask up again is that so many people are unvaccinated. So go get your shots and tell your friends and neighbors to do the same.