Pertussis epidemiology in Turkey: Are booster doses necessary? [Türkiye'de bogmaca epidemiyolojisi: Pekiştirme aşi dozlar? gerekli mi?]

Aim: In Turkey, routine childhood pertussis immunization with whole cell pertusis vaccine (DTP) has been given since 1968. Pertussis vaccine has been administered in the 2nd, 3rd, and 4th months of life, in combination with a booster dose administered between the 16th and 24th months. Acellular pertussis vaccine has been administered since 2007. It is observed that vaccination coverage rates steadily increased and pertussis incidence decreased by years (with time? over the years?). Third-dose DTP vaccination coverage increased from 1970 (20-30%) to 2005 (90%). In 2005, pertussis incidence tended to decrease (0.38 per 100.000) compared to 1970 (21 per 100.000). According to the available data of the Ministry of Health, Turkey appears to be reaching the WHO target, with a pertussis incidence of <1 case per 100.000, except for East Anatolia. However, pertussis still affects all age groups, especially adolescents, adults, and young infants in Turkey, and occurs endemically with 2- to 5-year cycles of increased disease incidence. It was noticed that the number of cases increased in 1997 and 2004 despite increased coverage. The incidence of reported pertussis among adolescents and adults has increased over the past decade in our country. Even though only up to 6.5% of the cases were ? 15 years of age until 2005, 16.9% of them were included in this age group in 2005. Consequently, the four doses of infant pertusis vaccination administered in Turkey is not sufficient for longlasting protection against the infection. A large number of schoolchildren, adolescents, and adults are susceptible to pertusis infection, and therefore improvement in vaccination procedures in our country is necessary. Booster doses of pertussis vaccine for pre-school children and adolescence might be considered.