Coronavirus rates continue to steadily decline in the greater Washington region after a surge brought on by the highly contagious delta variant, but public health experts say it’s too early to declare victory against the unpredictable virus.

And with flu season around the corner, some hospitals are still at or near capacity with covid-19 patients and people who put off care at the height of the pandemic, meaning there’s little room for an influx of flu patients this winter. Officials are bracing for the possibility of a severe flu season and encouraging people to get a flu vaccine on top of a coronavirus vaccine.

“We’re heading in a better direction than we were a month ago, but we’ve been here several times before,” said Boris Lushniak, dean of the University of Maryland School of Public Health. “I don’t want to diminish optimism, but it’s not over yet.”

Pfizer booster shots are already being administered to the vulnerable, and Virginia and Maryland officials say they are prepared to give Moderna and Johnson & Johnson boosters as soon as federal officials give the green light.

Vaccination remains the most effective way to prevent coronavirus and its variants. During 19 months of the pandemic, covid-19 has killed more than 724,000 people in the United States, including 25,000 people in the District, Maryland and Virginia.

New infections and hospitalizations are down dramatically in the District and Virginia and less so in Maryland, where the surge fueled by the delta variant was less severe overall.

Virginia, a large state with more rural areas, still has the highest numbers in the region, with a weekly average of 24 infections per 100,000 people, compared with 42 a month ago. The seven-day average of hospitalizations is down to 1,497, compared with 2,070 at the same time last month, data shows.

Maryland, where some counties close to D.C. have imposed mask mandates, has a weekly average of 15 infections per 100,000 people, down from 20 a month ago. The weekly average of hospitalizations is down as well, to 854 from 1,019 a month ago, data shows.

In D.C., the seven-day average of cases per 100,000 people is 14, compared with 38 a month ago, and the seven-day average for hospitalizations is down to 103 from 142 a month ago, data shows.

Despite the positive data trends, Lushniak said another variant could appear the way delta did, and he warned people to “be wary of premature declaration of victory over this virus” and “not let our guard down.”

He encouraged people to get a flu shot in addition to a coronavirus vaccine and stressed that in the crush of information about the pandemic, people may need to be reminded that the coronavirus vaccines do not protect against the annual flu.

Last year, flu season was relatively mild because people were strongly adhering to covid-19 prevention measures — social distancing, masking and frequent hand-washing — which also are effective against the flu.

As people grow weary of these practices, “who knows what this flu season will hold,” said Rajat Chand, chief medical officer at Inova Fair Oaks and a physician in the emergency department. In a normal year, the flu can kill 40,000 to 60,000 Americans, he said.

Stakes are higher than usual because hospitals, including those in the Inova system, are at or near capacity caring for covid patients, people who delayed care and surgery during the height of the pandemic, and illnesses among people returning to work and school, he said.

Chand urged people to get a flu vaccine, which, like the coronavirus shots, is “amazingly effective at preventing hospitalization and death.”

In the District, walk-up coronavirus vaccination sites will begin offering the annual flu shot in addition to coronavirus shots, if they haven’t already. Both vaccines are free.

Fort Stanton Recreation Center (1812 Erie St. SE) and Columbia Heights Educational Campus (3101 16th St. NW) started administering both types of vaccines last week. Starting Tuesday, Benning Library (3935 Benning Road NE) will give both as well.

Last week, an advisory committee of the Food and Drug Administration recommended booster doses of the Moderna and Johnson & Johnson vaccines.

The Moderna booster is recommended for people 65 and older, residents of long-term care facilities, and people 18 and older at increased risk because of underlying medical conditions or where they work or live. The Johnson & Johnson booster is for people 18 and older.

Although Pfizer boosters are already being administered in Virginia, Moderna and Johnson & Johnson boosters will not be given out until federal officials offer new guidance, which could happen this week, Danny Avula, Virginia’s vaccine coordinator, said in a statement Friday.

Gov. Larry Hogan (R) said Maryland is also prepared to administer boosters pending final approval.

“We’ll be ready to begin providing additional boosters for anybody who wants them, for anyone who has received J&J, Moderna or Pfizer,” he said Friday.

Hogan said the state has administered more than 200,000 booster shots so far, while Virginia data shows more than 300,000 state residents have been given boosters.

State and local officials are preparing for the approval of vaccines for children under age 12, which Hogan said he expects later this month or in early November.

“We’ve been working for three or four months to prepare,” he said. “They’ll be ready to provide a booster shot to every child that wants one.”

Michael Brice-Saddler and Ovetta Wiggins contributed to this report.