Health officials in Boston are working to contain a potential measles outbreak after a worker at the French consulate tested positive for the highly contagious illness, MyFoxBoston.com reported.

About 80 employees in the Park Square building, located in Boston’s Back Bay neighborhood, were vaccinated on Wednesday. Nearly 2,000 people work in the building, and city officials are now vaccinating any worker who has not had the recommended two shots to protect them against the infection.

The worker who tested positive last month is a woman in her 20s, according to the report. So far, she is the only person to become ill.

Measles is spread by contact with droplets from the nose, mouth, or throat of an infected person, and symptoms usually start to kick-in between eight and 12 days after a person is exposed to the virus.

Common symptoms may include cough, fever, runny nose and a rash.

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