SAN DIEGO (NEWS 8/CNS) - Due to overwhelming demand, a second clinic was added Friday for seniors to get a second hepatitis A vaccine necessary to maintain long-term immunity against the disease.

Serving Seniors administered 115 vaccines on Thursday. In order to help meet demand, the nonprofit today will administer 90 doses of the shot that offers immunity against hepatitis A, which has killed 20 and sickened 584 in the region to date as part of a recent outbreak.

"Seniors should take the recent San Diego hepatitis A outbreak very seriously as it is extremely transferable and potentially deadly to seniors and those with compromised immune systems," according to a statement released by the organization. "Serving Seniors is dedicated to protecting San Diego seniors from hepatitis A through ongoing education, improving internal protocols, offering vaccinations and having many sanitization stations available throughout their facilities."

The clinic was scheduled to run until 1 p.m. at Serving Seniors' Potiker Family Senior Residences, 525 14th St.

Vaccination efforts in the county ramped up last year amid an outbreak of the disease, which attacks the liver. The county vaccinated more than 127,000 residents in the last year as part of its response to the outbreak and health officials say now may be time for a second shot.

Those who received their first hepatitis A vaccination before mid- September should now get their second dose, the officials said.

The first dose is about 95 percent effective in preventing infection. But that effectiveness decreases over time. The second shot boosts immunity for between 20 and 40 years, according to the Centers for Disease Control and Prevention.

Vaccines can be obtained at a doctor's office, pharmacy or county public health center. A second vaccine can be obtained at any of those locations regardless of where one received the first vaccine. Those without insurance can go to a county public health center to get vaccinated. For a list of locations, visit or call 211.

The start of the outbreak was traced back to November 2016. By early May 2017, there were 80 cases reported and three deaths.

The county public health officer at the end of last August directed the city to sanitize streets and sidewalks and expand access to hand-washing facilities and restrooms in an effort to cut down on the amount of human waste on San Diego's roads, one of the ways the disease was spread.

The county Board of Supervisors last September first declared a state in emergency over the outbreak, which was lifted at the end of January amid a declining number of cases.

Hepatitis A, which can be deadly, usually is transmitted by touching objects or eating food that someone with the virus has handled or by having sex with an infected person.

The disease doesn't always cause symptoms, which can include fever, fatigue, nausea, loss of appetite, yellowing of the eyes, stomach pain, vomiting, dark urine, pale stools and diarrhea.