The largest simultaneous screenings for hepatitis B took place across California today as part of World Hepatitis Day.
Screenings were held at 10 Bay Area sites, including one at ThinkTank Learning in Palo Alto.
Organizers said it is important to get the screenings because two-out-of-three people do not know they are infected and could develop liver cancer or liver disease if untreated.
Pacific Islanders are particularly susceptible to hepatitis B. A simple test is used to detect it.
Students from the ThinkTank got the word out about the vaccine.
"Young people are bringing in their families and spreading the word," Menlo Park Assemblyman Rich Gordon said. "The more people who understand that this is something that you need to be screened for, the better off we will be."
The vaccine is said to protect an individual for life.