Fig 4. The prevalence of HBsAg, anti-HBs, and anti-HBc among populations residing in four parts of Thailand.

The seven age groups were <5, 5–10, 11–20, 21–30, 31–40, 41–50 and 51–60 years plus (x-axis). The y-axis represents the percentage of the population with positive HBsAg (A), seroprotective anti-HBs (B) and positive anti-HBc (C).