While delta variant is still called COVID-19, everyone needs to reset their assumptions and think of this particular mutation in an entirely different way. As a practical matter, this is an altogether different virus.

It spreads much more quickly and easily, infecting mainly the unvaccinated but also some of those fully vaccinated who have been exposed to the elevated virus levels. Activities that in recent months have been deemed safe simply are not any longer.

That much, everyone could see from the multiple 600-plus infection counts that stunned the islands last week. Here, residents had prided themselves on managing the coronavirus relatively well.

No more. This is a virus that has evolved into a dire threat, and the people’s response has to move at warp speed, not slowly evolve, to head off the real danger to the community.

What they need are real pushes from leadership to get the vaccine in a surge to match the latest outbreaks, and to immediately change their social behaviors to limit the spread of the virus.

On crowded Oahu, where the social gatherings have grown in uncontrolled fashion, it’s especially crucial for alarm bells to ring. The one who should be ringing them, but who has been oddly passive, is Mayor Rick Blangiardi.

Blangiardi, speaking Thursday at a news conference with the governor and other county mayors, said he supported the announced plan to check vaccination status of all state and county workers, an important step and the principal reason for the press briefing.

But it’s just not enough. Oahu is the county with the greatest peril from COVID-19, and the mayor’s job is to use the political bully pulpit, something Blangiardi rarely does.

This is the moment to shout the need for vaccinations from the mountaintop, and the city’s chief executive is simply standing at the summit. Immunization is, as Blangiardi says, the surest route out of the surge, but it’s not the only important message he needs to convey. He and his team also should be out in front, helping to counter the misinformation about the vaccine that’s circulating with delta-variant efficiency.

Further, he must issue the call for residents to curb their social activities. The best way to convey the urgency is to reinstitute a lower limit on social gatherings — something adapted from the Tier 4 restrictions Honolulu left behind weeks ago. Keeping the ceiling on gatherings to 10 people indoor and 25 outdoor (down from the current limits of 25 and 75, respectively) could curb the spread without doing further damage to Oahu businesses.

The mayor on Thursday said he does not intend to add restrictions because the roughly 250,000 people who qualify for the vaccine but have not received a shot are in the minority. He added that the most people are best served by boosting the vaccine uptake.

That’s right, but in the meantime? Delta moves fast, and it won’t wait for the gradual immunization process to advance before further ravaging the population.

The imperative is to get people to curb their social activities — immediately. This way, the viral load in the community can be reduced, crucial to cutting the risk of infection to vaccinated and unvaccinated people alike.

This necessarily means enforcement, and the mayor should call on the Honolulu Police Department to resume increased patrols. Police presence will drive the point home that Oahu is in a new, more precarious phase of the pandemic.

Then, as now, the risks of exposure to the virus were not well understood, so caution becomes the wiser course.

This social-gathering restriction would be for the short term until, with the help of increased vaccination, case numbers come back under control.

Last week’s decision by Gov. David Ige and the mayors to boost shot requirements for state and county workers should help make inroads toward that goal. The essence of the order, effective Aug. 16: Employees have to show that they are fully vaccinated or be subject to weekly COVID-19 tests in order to come to work.

It’s been criticized by public employee unions, less for the policy itself than for the hurried way it’s being rolled out, and with insufficient union consultation.

True — the details of how and where testing will be conducted and who will bear the cost are not set, and on how exemptions will be evaluated.

But these are not ordinary circumstances. The state and county do not have the luxury of time to finalize all the details before communicating the new requirements to employees, many of whom would opt to take the shot promptly and minimize their burden of testing.

Even more critically, time is short for beating back the virus. The longer delta continues to swirl, unchecked, through Hawaii, the greater the chance of a more destructive variant, one that could leave even the vaccinated entirely unprotected.

It falls to local residents, whose own social interactions are fueling this dangerous surge, to take action — with the officials they elected leading the charge.