BALTIMORE, Md. – Maryland schools plan to ban thousands of students from attending class over new mandatory vaccine requirements.

Maryland students are required to receive vaccinations for chicken pox, tetanus, diphtheria, pertussis, and meningitis and parents are required to provide proof within 20 calendar days from the start of school, but thousands of students across the state are out of compliance, the Baltimore Sun reports.

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Next week, students without the proper immunizations will be banned from class until their parents provide proof they received the shots.

“… Baltimore County barred hundreds of children from school this week after failing to meet a Tuesday deadline for required vaccinations,” according to the news site.

For Baltimore City schools, the number of students who could miss out on class next week is in the thousands, as 3,800 were without the required vaccinations Wednesday.

The new requirements apply to students in kindergarten, first, second, and seventh through ninth grades based on a schedule of immunizations with different required vaccines for different grades.

Younger students are required to receive two doses of Varicella, to protect against chicken pox, while older students also need immunizations for tetanus, diphtheria and pertussis known as Tdap, as well as a dose of Meningococcal vaccine to guard against meningitis, according to the Sun.

“I cannot stress too strongly how important this is,” Baltimore city schools CEO Sonja Santelises told school board members this week.

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The Sun took a tally of the number of students out of compliance in numerous districts, which included about 600 students in Baltimore County, about 89 students in Anne Arundel County, and fewer than 40 in Carroll County. Two other school districts were unsure how many students have not received the mandated immunizations.

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“More than 6,400 children in Prince George’s County started the school year without state-required immunizations, prompting urgent phone calls warning parents that children will not be allowed into classrooms tomorrow,” WUSA reported in late August.

Groups like the Maryland Coalition for Vaccine Choice have fought for parents’ rights to immunize their children as they see fit, pointing out conflicting science on the need for vaccines for young children.

Parents in Maryland and virtually every other state have opposed efforts to force them to vaccinate their children for a variety of reasons, from religious objections to health concerns to philosophical reasons. Proponents of vaccinations argue that parents put entire schools at risk by failing to protect against preventable diseases.

In Maryland, parents can opt out of the required immunizations only for medical or religious reasons, and they must obtain documentation to prove their reasoning is legitimate.

Filipa Gomes, health services director for Carroll County Public Schools, told the Sun that many of the students out of compliance who risk missing out on class have been vaccinated, but district officials simply don’t have their records on file.

“In a lot of these situations the students have the immunizations; we just haven’t received the records from the parents,” she said. “Once they got the call from the school principal, ‘We need your records,’ all of a sudden a lot of them came in.”

Baltimore city schools and numerous other districts have launched free health clinics where parents can bring their children for their government-mandated shots.