Increased incidence of pertussis has been reported in all age groups in recent years. This is probably due to waning post- vaccination immunity, antigenic divergence between clinical isolates and vaccine strains due to adaptation of Bordetella pertussis and improved laboratory diagnostics.
A few years ago, a safer acellular vaccine against pertussis replaced the more reactogenic whole-cell vaccine. Recent studies, however, indicate that, a combination of both types of vaccines would be ideal for sufficient and long-lasting protection.
Booster shots are currently recommended in adults, including booster doses for susceptible people in close contact, especially newborns and infants, the so-called cocoon strategy.