About 1 in 420 Americans has died of covid-19, according to official data. And we’re still averaging more than 1,000 deaths per day.

But in certain areas — and indeed in many areas in which the population is much more tightly packed and the coronavirus could transmit more easily — the story is far less grim. A big reason: widespread vaccination. Death rates are far below the national average in the most-vaccinated, often-urban areas.

Much has been written about the yawning gap in outcomes between less-vaccinated and more-vaccinated areas, especially as deaths in less-vaccinated, red states significantly and increasingly outpace more-vaccinated, blue states. The Washington Post’s Philip Bump also reported this week that deaths in red counties are more than 50 percent higher than in blue counties.

But even that might undersell just how beneficial vaccination is in preventing the worst that the coronavirus has to offer — particularly when adopted on a grand scale in a given area.

From the start of the vaccination effort, a pertinent question has been when we might achieve something amounting to “herd immunity,” i.e. having enough people vaccinated to stomp out the virus. Guesstimates often pegged that number at 70 percent or above. That concept has proven elusive, particularly as the delta variant has rendered the vaccines less effective at preventing the spread — while still extremely effective at preventing hospitalizations and deaths.

But those latter metrics remain hugely important. And in the densely populated areas in which we’ve approached overwhelming adoption of the vaccines, the death rates are often a fraction of the national average — a significantly greater gap than between the most-vaccinated and least-vaccinated states.

Perhaps the most highly vaccinated large county in America, according to New York Times data, is Montgomery County, Md., just outside the District of Columbia. Data from the Centers for Disease Control and Prevention show 93 percent of those 12 and older there are fully vaccinated, compared to around 70 percent nationally. The number dying daily over the past week is eight times as high nationally — 3.4 per 1 million — as it is in Montgomery County — 0.4 per 1 million — even as Montgomery County is near some virus hotspots.

The relative rate is similar in two of the handful of other most-vaccinated large counties in the country: Dane County, Wis. (home to Madison), where 86 percent of people 12 and older are fully vaccinated, per the CDC, and San Francisco, where 84 percent are vaccinated. Dane County also has 0.4 deaths daily per 1 million despite being in one of the most hard-hit regions, the Midwest.

Slightly fewer people 12 and over are vaccinated in New York City, though still north of 80 percent. Over the past week, it has registered a per-capita death rate about one-third the national average.

Similar to New York City are Multnomah County, Ore. (home to Portland), with its nearly 83 percent full vaccination rate for those 12 and over; Alameda County, Calif. (home to Oakland) at 84 percent; and Santa Clara County, Calif. (home to San Jose) at nearly 90 percent. In each case, there is about 1 death per 1 million people, compared to 3-per-1-million at the national level (as well as more than 3 deaths per million daily statewide in Oregon and more than 2 per million in California).

There are some larger, highly vaccinated counties with rates that are comparable to the national average. These come particularly in the Denver area — Denver itself (79 percent 12 and over fully vaccinated, 3 deaths per 1 million) and Boulder County (79 percent vaccinated, 2 deaths per 1 million) — and in Minneapolis-based Hennepin County (78 percent vaccinated, 3 deaths per 1 million).

But they also come in slightly less-vaccinated counties than the above and in states that are significantly more hard-hit than the rest of the broader country right now. These counties’ per capita death rates are also still about half or less compared to the rest of their states (more than 6 deaths per million in Colorado and 7 deaths per million in Minnesota).

So while the most-vaccinated states are significantly, incontrovertibly and increasingly better off than the less-vaccinated states, the difference is even starker at the county and city level — and even as many of these highly vaccinated counties also happen to be the most densely populated.

Correction: The vaccination rate in Santa Clara County was initially misstated as 81 percent. It is, in fact, 89.6 percent of those 12 and over, according to the CDC.