Pertussis due to infection with Bordetella pertussis (B pertussis) is a well-known cause of persistent cough primarily affecting infants and young children. Repeated administration of the vaccine is often needed to reduce the disease burden and control its transmission. At this time, no data are available on the epidemiology of pertussis in adolescents and adults in Kazakhstan.~The aim of the present study is to estimate the prevalence of pertussis infection in different age groups in Kazakh children and adolescents using the anti-pertussis toxin (PT) antibodies (IgA and IgG) as specific marker of pertussis infection or vaccination. The serosurvey will be conducted in 4 different regions: Aktobe, Karaganda, Taldykorgan, and Shymkent.~Participants (≥ 10 years & < 19 years) attending the study centers will be asked to participate in the study. The adolescent participants and the parents/guardian(s) of all participants will be informed about the procedures and data handling. Written informed consent from one parent/guardian needs to be obtained by the physician before any blood samples can be taken.~Upon obtaining informed consent for participant parent/guardian, the study coordinator will complete an investigation form (IF) for each participant and collect serum samples. The specimens will be coded by a unique participant number and delivered to the laboratory in charge of the assay. The specimens will be used for serological analyses.
Seroprevalence of pertussis among older children and adolescents in Kazakhstan: A cross sectional study.~Justification: to describe the distribution of anti-pertussis toxin (PT) antibodies (IgA and IgG) in a population aged 10-18 years old according to sociodemographic characteristics, vaccination history, and risk factors of pertussis infection.