Maryland over the weekend reported its first consecutive days with zero deaths from the coronavirus since the early days of the pandemic — a symbolic benchmark suggesting the region has entered a new, more hopeful phase in its fight to stop the spread of the virus.

On Monday, D.C. reported zero deaths over the weekend. Virginia reported a single death on Saturday, but the numbers crept up on Sunday and Monday — a reminder that the virus can still claim lives, especially in areas where vaccination rates are relatively low.

Public health experts and elected officials say the numbers are good news but issued a reminder that daily ups and downs are less reliable than trends over time and warned that there are health risks for the unvaccinated, including children under 12 and the immunocompromised.

Both Virginia and Maryland have reported cases of the highly contagious delta variant of the coronavirus first detected in India, which the CDC says could soon become the dominant strain of the virus in the United States. Virginia has found 41 cases of the delta variant. Through genetic sequencing, Maryland also has detected 41 cases of the variant, Department of Health spokesman Charlie Gischlar said. Variant data for D.C. was not immediately available.

At the peak of the winter surge in coronavirus cases in D.C., Maryland and Virginia, more than a hundred residents were dying daily of covid-19. In February — the deadliest month on record for the region — 3,177 covid-related deaths were reported.

Since then, much of the region has embraced the vaccines — and case numbers and deaths have begun falling.

“We turned the corner in May, and those numbers are holding,” D.C. Mayor Muriel E. Bowser (D) said. “We’re still very focused on vaccinations — specifically vaccinating all the folks out there who need it the most.”

As of Monday, the seven-day average in fatalities in the region had dropped to nine — the lowest since April 2020, when coronavirus testing was still limited. Both the District and Maryland reported no new deaths for two days in a row this week, although Virginia is still reporting at least one death per day and as many as 14 one day last week.

Case counts and test positivity rates are also on a decline across the region, particularly in places with high vaccination rates.

“There are two Americas, as they say. If you’re in vaccinated America, things are really, really good for you right now,” said Neil J. Sehgal, an assistant professor of health policy at the University of Maryland’s School of Public Health. “If you’re in unvaccinated America, well, there’s still a risk for you — and it’s not small.”

Coronavirus cases have been declining in the Washington region since mid-January, plummeting in April and May as more people got vaccinated.

D.C. on Monday reported a seven-day average of seven new infections daily, compared with a high of 523 in early January; Maryland reported an average of 65, down from 3,000 six months ago; and Virginia posted an average of 136, down from 5,500.

Lilian Peake, the state epidemiologist for Virginia, cautioned against reading too much into day-to-day reporting of deaths because the numbers reflect deaths that have happened in the past, not necessarily what is happening with the pandemic in real time.

Virginia officials rely on weekly reports issued by the Centers for Disease Control and Prevention for context.

In the national ranking of cases per 100,000 residents, in the week ended June 10, Maryland had the sixth fewest cases; Virginia ranked seventh, and the District ranked 11th.

For deaths per 100,000 residents, in the same week, Virginia had the 27th fewest deaths; Maryland ranked 29th. D.C. had the third fewest deaths, the CDC data shows.

Although infection, death and hospitalization numbers are down across Virginia, there are pockets of higher transmission in the Southwest and Southside that border states with higher transmission — West Virginia, Kentucky, Tennessee and North Carolina, Peake said, adding that the state has not done a comprehensive analysis.

In Montgomery County, Maryland’s most populous, more than 65 percent of residents have gotten at least one shot of a vaccine — higher than both state and county averages. The number of cases per 100,000 residents has dipped to 0.7, and test positivity is at 0.4 percent, lower than other large jurisdictions in Maryland.

“Our numbers continue to trend in the right direction,” Deputy Health Officer James Bridgers said at a news conference Monday. But the county cannot yet say the pandemic is over, he added, noting that county and state officials are trying to vaccinate underserved communities.

County council Vice President Gabe Albornoz (D-At Large) said he was heartened to see some Montgomery residents still wearing their masks indoors at restaurants and other crowded locations, even though it is no longer required by state or county law.

“I think it’s a good sign that county residents are transitioning more cautiously, as we have done through the pandemic,” he said. He added that he personally is still wearing masks in some public settings because he has four young children, three of whom are not yet eligible to be vaccinated.

Sehgal said high education rates in the county and in the greater Washington region in general mean people are more likely to trust vaccine science and get the shot.

When there are pockets of community transmission, they don’t explode into dozens of cases because the virus “cuts off” once it reaches a vaccinated individual.

“That spillover benefit of being protected by my friends and neighbors is quite strong,” he said.

Nonetheless, Sehgal said, disparities in vaccination rates persist, which mean some communities are still more vulnerable to the disease than others.

In the District, for example, Wards 7 and 8 consistently record more infections than wealthier parts of the city.

Over the weekend, Bowser and Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, knocked on doors in Southeast Washington in hopes of swaying residents in neighborhoods with some of the lowest vaccine uptake. They were joined by 163 volunteers.

Asked whether she felt their pleas were effective, Bowser said: “I absolutely do.”

Sehgal said that when the pandemic does eventually end, it won’t necessarily be with a startling statistic or noticeable trend.

“When the pandemic ends, we might not even notice,” he said. “The ways pandemics end isn’t with something very apparent. There’s no finish line. We’re going to see these numbers continue to drop, and eventually we’ll realize that we’re out of it.”