With the school year well underway, Northern Virginia districts are still fine-tuning the logistics of learning amid the coronavirus pandemic — while redoubling efforts to fight it.

Fairfax County school officials shared this week that the school system of 180,000 will launch comprehensive testing programs for unvaccinated students and staff members starting in November. The district is also brainstorming ways it can help vaccinate children under 12 once the federal government approves the vaccine for that age group, including by holding vaccination clinics at school and transporting families to other vaccination sites.

Superintendent Scott Brabrand highlighted that coronavirus cases and quarantine numbers are declining week-to-week in Fairfax County Public Schools and said rates of in-school transmission are vanishingly low. In the past month, he said, 567 students and 147 staff members have reported contracting the virus, representing about 0.35 percent of the population.

“One-third of 1 percent,” Brabrand said, repeating the number for emphasis. He added that “there has not been one case of school closure in FCPS.”

The vast majority of children in the Washington region are back in classrooms this fall, some for the first time in a year and a half. Children learning in-person have faced a raft of safety measures, including mask requirements and, for student-athletes, vaccine mandates. The precautions appear to be working: The only school closure reported so far in the D.C. area this academic year came in Prince William County Public Schools this month, when the Northern Virginia system was forced to make an elementary school online only for about a week because of a coronavirus outbreak.

Unlike neighboring school systems, Arlington Public Schools decided to offer remote learning to any parents and students that preferred it. At a school board meeting last week, officials with the Northern Virginia district said their virtual learning program was working well for the more than 600 children who chose it. Ninety-five percent of online students in Arlington are logging into Canvas, an online learning platform, and accessing Microsoft Teams, a videoconferencing tool, officials said.

A total of 630 students are engaged in virtual schooling this year, Arlington officials said, including 175 at the high school level, 173 at the middle school level and 282 at the elementary school level. Students of color were more likely to select remote learning: The online student body is 36 percent Hispanic, 24 percent Black, 17 percent Asian and 17 percent White. Thirty-nine percent of Arlington’s online learners are children whose first language is not English, 60 percent qualify for free and reduced-price lunch programs, and 24 percent are students with disabilities.

The system had initially stumbled in rolling out its online offerings, after a staffing shortage forced hundreds of students to miss class. But Arlington, which enrolls about 26,000, has since filled all its empty virtual positions, including hiring a school principal and a school counselor, administrators said Thursday.

Now, as flu season and winter breaks approach, school districts in the Washington region are getting ready to enforce vaccine mandates they issued earlier in the fall for employees. For Arlington, that deadline arrived Friday. The vast majority of school staffers in the area are already vaccinated, but thousands have refused to comply, meaning they now face regular testing or possible punishment. In Maryland’s Prince George’s County, for instance, some unvaccinated employees have been placed on unpaid leave after failing to submit weekly testing results as the district requires.

The Fairfax school system mandated vaccination for its roughly 28,000 employees but allowed staffers to opt out without requiring a reason, while mandating that anyone unvaccinated after Nov. 1 must undergo weekly testing.

In a survey completed by 92 percent of staff, 97.6 percent reported being fully vaccinated as of Oct. 12. Roughly 3,000 employees remain unvaccinated, Fairfax officials said Tuesday.

Beginning Nov. 1, Fairfax will launch its regular testing program for these employees. The rapid tests will be administered each week by a third-party provider at nine designated off-campus areas.

That same week, Fairfax will also begin weekly testing for student-athletes older than 12 who remain unvaccinated for medical or religious reasons. The district adopted a vaccine mandate for student-athletes earlier in the fall. About 2,000 student-athletes will have to undergo testing each week, officials said, although they will do so only with parental permission. If the result on that initial rapid test is positive, it will be followed by a confirmatory PCR test, known to be more accurate.

The second week in November, Fairfax will launch random screening testing for unvaccinated elementary-school students; testing for unvaccinated middle- and high school students will begin the following week. The effort is intended to help gauge levels of community spread and infection rates.

Only students whose parents consent to the testing will be eligible. Fairfax officials said Tuesday that roughly 11,000 to 12,000 students across the entire system will participate each week.

Also on Tuesday, Brabrand, the Fairfax superintendent, revealed changes to the school district’s snow day policy. Fairfax will offer traditional days off for the first five days that bad weather — of any kind — forces the school system to close. After that, the system will hold virtual learning days rather than give students time off.