With less than seven weeks left until the opening of school, several Washington area jurisdictions still need to hire hundreds of teachers, especially in such hard-to-fill subject areas as special education and math.

Fairfax County has signed contracts with more than 800 new teachers but needs nearly 800 more. The District has 400 vacancies left, down from more than 1,100 this spring. Prince George's County has hired about 700 of the 1,300 teachers it needs.

The vacancies persist despite unprecedented hiring efforts by some school systems, which are offering signing bonuses and other perks and staging record numbers of job fairs and recruiting trips.

School officials said they are facing a national shortage of teacher candidates in certain fields, as well as stricter hiring standards and a growing demand for more teachers so class sizes can be smaller in the earlier grades. They said that they are working feverishly and that they believe they will have enough teachers in classrooms this fall.

But union and parent leaders expressed concern, especially about Prince George's, where nearly one out of five teachers is uncertified and the new superintendent, Iris T. Metts, has mandated that all future hires be fully certified.

"I know she's making a great effort," said Celeste Williams, president of the Prince George's teachers union. "[But] I think most of us can use our imagination and know we're talking about working a miracle."

"It's scary, in my opinion," said D.C. school board member Tonya Vidal Kinlow (At Large), who has two children in the school system. "I know that they've been working very hard to try and get teachers here . . . [but] if we don't, I at least want us to know what our next plan is."

Prince George's County is holding a teachers' job fair Saturday morning -- unusually late in the season -- at Eleanor Roosevelt High School in Greenbelt. D.C. officials traveled to Richmond yesterday to interview prospective candidates, and personnel chief Katrina Robertson Reed said interviews will continue six days a week -- "and on Sunday if we need to" -- until all jobs are filled.

"I'm not worried," said D.C. Superintendent Arlene Ackerman, who hopes to have a total of 5,300 teachers on board by fall.

She said the District has whittled the number of uncertified teachers from 1,300 to fewer than 400 in three years, although it may bring back some more uncertified teachers temporarily if vacancies persist.

The city has fewer than 90 vacancies remaining for teachers in elementary school classrooms, which Ackerman considers the most critical positions. "We've never been that close with this much lead time," she said.

Montgomery County avoided the last-minute rush by launching recruiting efforts as early as September and touting its system's top salaries for senior teachers, low turnover rate and favorable working conditions. Officials have hired 800 of the 900 teachers they need.

"We start early and we hire aggressively," said personnel director Elizabeth Arons. "We know that we see the best applicants between January and May."

But other, smaller school systems still have large numbers of vacancies. Howard and Prince William counties have hired only two-thirds of the teachers they need, and Charles County has filled just 60 of its 140 vacancies.

"We've recruited farther than ever before," said a frustrated Keith Hettel, human resources chief for Charles schools. He said the number of applicants in some subjects has declined by as much as 50 percent.

"We see a lot more applicants shopping this year," Hettel said. "They're looking for the best contracts. They know they're in demand."

Officials in Northern Virginia said they did not anticipate any problem filling most vacancies. "We feel like we're pretty much on track," said R.L. Fitzgerald, personnel director for Prince William schools. But he echoed other educators' concerns about a dearth of teachers in certain specialties.

"Where we are having difficulties is with math, science and special ed," said John Felicitas, a human resources official for St. Mary's County schools. "Every county finds them the hardest to fill."

The District -- which needs 100 special-education teachers -- is doubling its $1,000 signing bonus for them and tripling the bonus to $3,000 for teachers certified in both special education and bilingual education.

In Fairfax, officials sought to head off the hiring crunch by offering contracts earlier in the school year. But they still have filled only half their vacancies. Efforts have focused on candidates for the specialty subjects -- special education, Spanish, physics, industrial technology -- who are in demand everywhere.

"I think we're well positioned to have everyone we need on board by the opening of school," said Kevin North, director of employment for the Fairfax system. Staff writers Hannah Allam, Amy Argetsinger, Victoria Benning, Marcella Bombardieri, David Nakamura, Linda Perlstein, Christina A. Samuels, Brigid Schulte and Liz Seymour contributed to this report.

Teacher Shortage

Washington area schools are running out of time to hire new teachers for the fall. Some jurisdictions still lack hundreds of teachers.

County New hires Vacancies

Anne Arundel 320 180

Calvert 78 23

Charles 60 80

D.C. 730* 400

Fairfax 840 760

Howard 293 137

Loudoun 300 100

Montgomery 800 100

Prince George's 700 600

Prince William 222 128

St. Mary's 110 30

*Includes 329 provisionally certified teachers who are being rehired and are working toward full certification.