Health officials say eight people in Los Angeles County have been diagnosed with bacterial meningitis so far this year.
The Department of Public Health will offer free vaccinations to people without health insurance beginning Thursday.
Officials say of the eight cases, four involved men who have sex with other men, including three who were HIV-positive.
As a result, the county is urging vaccinations for some gay men, especially those with multiple partners or who share cigarettes or drug paraphernalia.
Three of the patients are known to socialize in the West Hollywood or North Hollywood areas.
Meningococcal disease can be spread through kissing and coughing or sharing beverages or cigarettes.
The infection can cause brain damage, hearing loss or potentially death.