An increase in whooping cough in most of the developed countries has been detected in the last decade.To determine whether the administration of dTpa vaccine instead of DTPa fifth dose is contributing to the appearance of these cases.A descriptive study based on cases of whooping cough reported during an epidemic period in the city of Alicante in the first 5 months of 2014. Only pertussis cases confirmed by PCR were included in the study, and only those vaccinated with 5 doses were included in the analysis of the period of protection.A total of 104 cases of pertussis confirmed by PCR were reported, with 85 cases (82%) having had 5 doses of vaccine. The mean time and standard deviation (SD) of protection was 2.1±1.1 years with dTpa, and 5.1±1.5 years with DTPa (p<.001). In the protection, adjusted for age, it was observed that, after 3 years, only 47.6% of people vaccinated with dTpa were still protected, while people vaccinated with DTPa were 100% protected (P<.001).This study found that people who were properly vaccinated against pertussis and received their last re-vaccination dose with dTpa had a shorter period of protection than those who were vaccinated with DTPa.