The Los Angeles school district is poised to remove its Jan. 10 student COVID-19 vaccine mandate, confronted with more than 30,000 students 12 and older who are not fully vaccinated and would otherwise be barred from campus, a significant step back from one of the nation’s strictest student vaccine mandates and a reprieve for parents who defied the rule.

Under a proposal from interim Supt. Megan Reilly, enforcement of the January deadline would be suspended until fall of 2022, the start of the next school year.

Though the mandate has probably resulted in thousands of students being inoculated — making campuses more protected from outbreaks — the district also was faced with the reality of tens of thousands of students being unable to attend in-person class under the rules. Unvaccinated students would have been placed in an existing independent study program, called City of Angels, that has struggled since the start of the year and would be hard-pressed to manage the sudden and potentially overwhelming influx.

By early this week, it already was too late for students to complete the five-week vaccination cycle. Students 18 and older have the option of completing a two-week vaccination cycle.

The Board of Education will make a final decision on delayed enforcement of the deadline at its Tuesday board meeting. But a Friday morning alert from Reilly indicated the change of plans is all but official.

L.A. school board member Nick Melvoin said that campus safety is paramount but still must be balanced against academic imperatives.

“There’s no playbook for navigating school through the pandemic,” Melvoin said. “And the north star of this board has been student success. And that’s meant their physical safety, but also their academic success. And that’s meant different things at different times. In March of 2020, it meant closing schools. In March of 2021, it meant reopening schools. In October — when we looked at the Delta variant, when we looked at vaccination rates — it meant the student vaccination requirement.”

But the circumstances have evolved again, Melvoin said. Moving large numbers of unvaccinated students into independent study would disrupt the education of both the unvaccinated and the vaccinated — as teachers and classes were shifted around.

In her statement, Reilly chose to focus on the positive — about 86.5% of students are in compliance. These students have received at least one shot, obtained a medical exemption or qualified for a rare deadline extension because of extenuating circumstances.

“Los Angeles Unified applauds the 86.52% of students aged 12 and older and their families who are in compliance with the vaccine mandate, and the many other families who are still in the process of adding their vaccine records to the system,” Reilly said. “This is a major milestone, and there’s still more time to get vaccinated!”

The nation’s second-largest school system remains committed to its student vaccine initiative, she said: “The science is clear — vaccinations are an essential part of protection against COVID-19.”

The success of the inoculation effort to date makes it possible to delay enforcement of the vaccination deadline and still maintain safe campuses, officials said.

A handful of other districts have imposed student COVID-vaccine mandates. They, too, appear to have large numbers of unvaccinated students.

In the Sacramento City Unified School District, 60% of students, about 11,000, have not yet complied with the Jan. 31 deadline and could be assigned to independent study if they don’t apply for an exemption, a district spokesperson said. The Oakland Unified school board pushed back its deadline by a month after hearing from families who were having difficult submitting documentation, according to KTVU news. The district reported that 38% of students remain unvaccinated or have not reported their status.

Culver City Unified, the first in California to mandate student COVID vaccines, had required students to be fully vaccinated by Nov. 19. With about 17% of eligible students (12 and older) non-compliant, the district has removed its deadline. The school system of about 7,000 students, which is adjacent to L.A. Unified, will focus on other safety measures, such as masking and coronavirus testing.

In L.A. Unified, the later deadline date lines up more closely with the state’s own pending vaccine mandate. It would go into effect for ages 12 and older no earlier than July, and only after a vaccine is fully approved for that age group by the U.S. Food and Drug Administration. So far, a vaccine is fully approved for ages 16 and older. Children ages 5 to 15 can receive the vaccine under a federal emergency-use authorization.

The White House responded to a question about L.A.’s step back with encouraging words.

Press Secretary Jen Psaki noted that “a large population of the school community” has complied, emphasizing the role of districts to set their own policies.

The pending delay was welcomed by some City of Angels teachers, who told The Times that they thought the program would collapse if thousands more students were suddenly added into it.

“Thank goodness vaccines delayed!” said City of Angels teacher Shawn Fornari.

Principals are already hearing from the latest wave of unhappy parents, said Nery X. Paiz, president of Associated Administrators of Los Angeles. Previously, the complaints came from anti-vaxxers and the vaccine-hesitant — as principals dutifully pushed the pro-vaccine message hard. Suddenly, pro-vaccine parents — as well as the vaccine-hesitant who gave in — are upset.

One concerned parent is Emily Skehan, who has a senior at Van Nuys Senior High and whose household includes an older, immunocompromised adult.

Her child and another in the household are in City of Angels “until everyone could be doubly/triply vaccinated,” she said.

“It is incredibly disappointing to see the district backtrack on their commitment to families like mine that have medically vulnerable family members and who have gone above and beyond to keep our community healthy throughout the pandemic,” Skehan said. “It feels incredibly unfair that a vocal minority of anti-vax parents have monopolized the conversation and now led the district to move backward on their commitment to community health.”

The families that defied the mandate — and took the risk of losing in-person classes — have won at least a temporary victory in a few school systems by not backing down, a reprieve that litigation on their behalf has so far not accomplished.

Charlene Mardesic and her husband had no intention of getting their 12-year-old sixth-grader vaccinated. They were agonizing about whether to home-school her or move out of L.A. Unified boundaries.

The delayed deadline brings relief, but she remains wary: “I’m just wondering if the only victory for us will come when we say, ‘That’s it. We’re done with L.A. Unified.’”

The change of direction in L.A. Unified also is expected to affect the district’s coronavirus testing program, which was about to be scaled back for the spring semester.

Under Reilly’s modified plan, L.A. Unified would require baseline testing for all students and staff at the start of the spring semester and continue with weekly testing for all, regardless of vaccination status, through January. Starting in February, only students without proof of vaccination would be required to test regularly.

In continuing the testing, the district is adopting a request of the teachers union, United Teachers Los Angeles. The union has supported the vaccine mandate both for students and employees.

Nearly 500 school district employees — out of 73,000 — lost their jobs this week as a result of the employee mandate, including seven holding a teaching credential. Most unvaccinated classroom teachers have been able to transfer to the independent study program, where those who are unvaccinated — teachers or students — have no in-person contact with others involved in the program.

On behalf of the Board of Education, Reilly has spearheaded the vaccine push and also is managing the current triage. She is soon expected to step aside from the top leadership role to make way for Alberto M. Carvalho, whom the board named this week as permanent superintendent. Since 2008, Carvahlo has been superintendent of the Miami-Dade County Public Schools.

Times staff writer Chris Megerian in Washington contributed to this report.