Pertussis Seroimmunity and One Year Immunogenicity of Combined Adult Type Pertussis Vaccine in Pre marriage Girls, 2009-2011

Background and After marked reduction of pertussis during recent two decades the incidence of disease is increasing, particularly in early infancy. The main sources of infection in this age group are mother and other household close contacts. Our purpose was to examine whether administrating prepregnancy pertussis booster dose can induce long-term protection enough to provide higher maternal antibodies levels to their offsprings compared with prebooster titers. Totally 114 healthy 18-35 year-old childbearing age women planning to become pregnant were boosted with one dose of adult type pertussis vaccine. Blood samples were obtained before, four weeks, and one year after boosting. Sera were tested for IgG antipertussis-antibodies using ELISA method. Descriptive statistical method and paired t-test were used to compare the data before and after vaccination. Seroprevalence rate and mean concentration of antibodies at before vaccination were 69.3% and 68.19 (SD 38.46) Eu/mL, respectively which significantly increased to 93.8% and 152.82 (SD 70.31) EU/mL, respectively. One year after vaccination these rates were significantly higher than before vaccination (82.4%, and 107.0 (SD44.75) EU/mL, respectively). Serologically recent pertussis infection was detected in 3.5% of the women. Pertussis booster immunization was safe, well tolerated and highly immunogenic and resulted in immunity which was preserved for more than one year. Further investigations with larger sample size and longer duration are recommended. According to these findings and review of literature, targeted prepregnancy pertussis vaccine boosting may be an alternative strategy to protect young infants.