DALLAS -- Mobile clinics are being dispatched to homeless centers across Dallas County. Health care workers are administering a vaccine to help prevent and fight Hepatitis A.

Dallas County Health and Human Services said the initiative to address the foodborne virus is part of a campaign in response to a national crisis that happened in San Diego County. Back in March 2017, an outbreak of Hepatitis A spread across that community’s homeless population.

Interim Director of Dallas County Health and Human Services Ganesh Shivaramaiyer says, "the Hepatitis A vaccine is 90 percent effective at preventing infection. One of the key components in San Diego County's response included vaccination acceleration against the virus that killed about 20 people and infected 578."

Shivaramaiyer explained Dallas County's initiative to administer vaccines to the homeless is an effort to reduce the risk of anything happening here.

The vaccine is about $50 per dose. It’s too expensive for many of the homeless residents to afford, and travel to clinics can be a challenge. That is why Dallas County Health and Human Services says it's being proactive is sending mobile clinics to shelters and areas where the homeless population congregates.

Shivaramaiyer says DCHHS has already administered 250 doses of the vaccine through eight mobile clinics, so far. The agency is prepared to give out about 750 doses at no charge to the homeless residents.

“It’s very important that we get to them before the virus gets to them, and then starts spreading and spirals out of control," Shivaramaiyer said.

The Hepatitis A virus infects the liver and is highly contagious. Symptoms include fever, nausea, headache, diarrhea, yellowing eyes, and joint pain among other issues.

DCHHS says there are some Hepatitis cases in Dallas County, but not to the proportion of an outbreak. The local vaccination campaign is an effort to be proactive.