A doctor prepares to administer a vaccine injection at New York-Presbyterian Lawrence Hospital in Bronxville, N.Y., in January.

Shepherd ISD notified parents this week that an outbreak of chickenpox had been reported at Shepherd High School.

In a statement on social media, the school district said it was monitoring the situation and "taking appropriate precautions ot help prevent further spread." The district is also asking parents to keep their children at home if they develop symptoms.

The district cited guidance for the Texas Department of State Health Services and said: "Students with suspected or confirmed chickenpox must stay home from school."

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According to the Mayo Clinic, chickenpox is caused by the varicella-zoster virus and can spread easily among unvaccinated people. The chickenpox vaccine is the safest way to prevent the illness.

Unvaccinated students may be required to stay home in some cases, the district said.

"During an outbreak, additional exclusion requirements may apply to students who have not been vaccinated or do not have evidence of immunity," the district said. "The school will communicate directly with affected families regarding any exclusion period or return-to-school instructions provided by public health authorities."

The district asked parents to watch for the following symptoms.

• An itchy rash that develops into fluid-filled blisters and eventually scabs
• Fever
• Tiredness or fatigue
• Loss of appetite
• Headache