Maryland has agreed to provide local school systems more time for students to get required vaccinations after school superintendents raised concerns about children missing school because they could not meet the deadline.

The state Department of Health and Mental Hygiene is offering a 45-day extension to allow students to get the required vaccinations. According to state rules, students must provide proof of their immunizations by the 20th day of school.

Local districts have been working with parents to adhere to the state’s regulations, but state officials said school superintendents asked in recent weeks that the state provide some flexibility.

“We know that all of our local systems are trying to balance keeping kids in class, which is important, with health concerns,” said Bill Reinhard, a state Department of Education spokesman.

School districts must apply by Friday to receive an extension, and a number of districts plan to file for extra time, including Anne Arundel and Prince George’s counties.

Prince George’s, which faced a Tuesday deadline to get its students vaccinated, made a final push on Saturday, sponsoring free immunization clinics where more than 500 students received the necessary shots.

Max Pugh, a spokesman for the school system, said the district’s new deadline would be Oct. 31.

Districts are eligible for the extension if they have more than 250 students who do not have proof that they have received their immunizations. The districts also must submit an outreach plan that outlines how they plan to identify students who don’t have the required immunizations and establish programs with groups that provide access to the vaccinations.

Students will be allowed to attend school during the extension and students in school districts that are seeking waivers also can go to school, said Laura Herrera, the state’s deputy secretary for public health services.

Students must be vaccinated for measles, mumps, whooping cough and other communicable diseases. Montgomery County health officials have recently had to deal with a whooping cough outbreak, with 16 cases surfacing among students between the ages of 9 and 18.

Starting this school year, Maryland public schools required students entering kindergarten to show they had received two chicken pox vaccinations, and students beginning the seventh grade had to have received the Tdap (tetanus-diphtheria-attenuated pertussis) and meningococcal vaccinations.