Incidence of rubella seronegativity in Hong Kong-born gravidae aged ≤25, comparing birth >1983 versus ≤1983.

<p>■ Overall group all gravidae: difference among groups p = 0.084, trend with age p = 0.016. ▲Gravidae born after 1983: difference among groups p = 0.006; trend with age p<0.001. • Gravidae born in/before 1983: difference among groups p = 0.027, trend with age p = 0.008</p

Maternal rubella seronegativity by age group, comparing between gravidae born > 1983 versus ≤ 1983.

<p>Maternal rubella seronegativity by age group, comparing between gravidae born > 1983 versus ≤ 1983.</p

Multivariate analysis on the association between teenage and birth after 1983 with rubella seronegativity.

<p>Multivariate analysis on the association between teenage and birth after 1983 with rubella seronegativity.</p

Levels of anti-hepatitis B surface antibody (anti-HBs) after booster vaccination for young adults.

<p>Each data point represents one student aged 17–23 years, born after the adoption of universal neonatal immunization for hepatitis B. All these 69 students were negative for HBsAg and anti-HBs before booster vaccination. Anti-HBs levels were determined one month after the first dose and 2–4 months after the third dose of booster vaccination with 20 mcg of ENERGIX-B (GlaxoSmithKline Biologicals, Belgium).</p