Pertussis vaccination during pregnancy in Belgium: Follow-up of infants until 1 month after the fourth infant pertussis vaccination at 15 months of age., Maertens, Kirsten, Caboré Raïssa Nadège, Huygen Kris, Vermeiren Sandra, Hens Niel, Van Damme Pierre, and Leuridan Elke , Vaccine, 2016 Jun 30, Volume 34, Issue 31, Number 3619, p.3613-9, (2016)