According to San Francisco officials, New York City has reported 12 cases of meningitis among gay men in the past year - three of those in the last six weeks.
San Francisco's recommendation went out on Thursday. The city's health officer, Tomas Aragon, says men who have recently traveled to New York City and had close or intimate contact with other gay men or plan to go there and have such contact should discuss vaccination with their doctor.
Meningitis is a potentially fatal bacterial infection that affects the tissues around the brain and spinal cord. It can spread through contact with spit or mucus.