Almost 80% of American school staff and child care workers have received at least one coronavirus vaccine dose, according to the Atlanta-based Centers for Disease Control and Prevention.

On Tuesday, the CDC released its new estimates on the same day President Joe Biden announced all U.S. adults will be COVID-vaccine eligible on April 19, ahead of his original May 1 deadline.

Biden, according to The New York Times, is continuing his ambitious push to reopen schools and return to in-person instruction by his 100th day in office. In February, Biden’s choice to run the CDC, Dr. Rochelle Walensky, said schools could safely reopen even if teachers haven’t been vaccinated against the coronavirus.

“Vaccination of teachers is not a prerequisite for safe reopening of schools,” Walensky said, citing CDC data showing social distancing and wearing a mask significantly reduce the spread of the virus in school settings.

Despite Biden’s in-person schooling push, the administration released data Wednesday showing large numbers of students are not returning to the classroom even as more schools reopen.

Nearly 46% of public schools offered five days a week of in-person to all students in February, according to the survey, but 34% of students were learning full time in the classroom. The gap was most pronounced among older K-12 students, with 29% of eighth-graders getting five days a week of learning at school.

Despite the slow progress, federal education officials see it as a step forward.

“There was a decrease in enrollment in remote-only learning and an increase in hybrid instruction at grade eight, providing evidence that more students are walking through school doors again,” Mark Schneider, director of the Education Department’s Institute of Education Sciences, said in a statement.

The findings are based on a survey of 3,500 public schools that serve fourth-graders and 3,500 schools that serve eighth-graders. It’s based on data from schools in 37 states that agreed to participate. This is the second round of data released from a new survey started by the Biden administration to evaluate progress in reopening schools.

As in January, the new results showed dramatic disparities based on region and race. In the South, slightly more than half of all fourth-graders were learning entirely at school in February, an uptick from the month before. In the same period, by contrast, the Northeast saw a decrease in the rate of students learning in the classroom five days a week, from 23% to 19%.

Overall, more than one-third of students in the South and Midwest were learning entirely at school, compared with less than one-quarter in the West and Northeast, according to the survey.

White students continued to be far more likely to be back in the classroom, with 52% of white fourth-graders receiving full-time, in-person instruction. By contrast, less than one-third of Black and Hispanic fourth-graders were back at school full time, along with 15% of Asian students.

The survey does not ask whether students are learning remotely by choice or because their schools do not offer an in-person option. But the wide gulf between school offerings and student learning data suggests that at least some students are opting to stay remote even after their schools reopen classrooms.

It matches previous findings from some of the nation’s largest school districts, where Black students have returned at far lower rates than their white classmates — a disparity that’s believed to come down at least partly to trust. Advocates say more must be done to convince parents that their children will be safe in school, especially Black families who have been disproportionately affected by the coronavirus.

Although wide racial disparities persisted in the new round of data, the Education Department saw a glimmer of hope in a slight increase among Black students learning fully in-person. From January to February, the rate ticked up from 28% to 30%.

The survey for the first time collected data on how many teachers have received COVID-19 vaccines, but the findings revealed little. More than half of schools said they did not know how many teachers got at least one shot. Of those with data, just 6% said that between 81% and 100% of their teachers had received a vaccination.

Coronavirus vaccines have not been approved for children under 16.