Seroprevalence of Bordetella pertussis antibodies in Flanders (Belgium).

To determine age-dependent pertussis immune response in the Flemish population, antibody levels to pertactin (PRN), pertussis toxin (PT) and filamentous hemagglutinin (FHA) were measured in serum samples from 1622 healthy 1-100-year-old subjects. For anti-PRN and anti-PT antibodies, peaks in GMTs were seen in infancy and again in the 10-15-year age group. After age of 20 years, anti-PRN GMT declined rapidly over a decade, followed by a slower decline. Anti-FHA GMT tended to rather increase progressively with age. These data confirm waning of vaccine-induced antibody levels and suggest pertussis resurgence during adolescence and young adulthood. These results support a pertussis booster vaccination policy for adolescents and adults.