As many as 5,000 people may have been exposed to hepatitis A after eating at a Red Robin restaurant in Springfield, Missouri.
According to USA Today, the concern was raised by health officials after a worker was diagnosed with the virus.
“Upon being informed of the incident, the Springfield Red Robin took all safety measures to ensure the well being of our guests and team members including arranging the inoculation of all Springfield team members with the immune globulin prophylaxis shot," Red Robin Gourmet Burgers officials said in a statement.
Springfield-Greene County Health Department is working with state and local officials to get as many customers as possible vaccinated within 14 days of being exposed to the illness.
The immunization is for people who dined at the restaurant between the dates of May 8 to 16.
The health department said the restaurant is safe and there is no longer a threat to the public.
Hepatitis A is usually spread through the feces of an infected person to food or drink that another person consumes.
Symptoms include nausea, vomiting, fever and yellowing of the skin or eyes.