Pre-booster seroprotection rates of pertussis were 25.2% and 31% which were raised to 70.3% and 85.7% upon immunization with DTwP-Local and DTwP-Pasteur vaccines, respectively (Table 2). the vaccination. All local and systemic reactions observed after vaccination were significantly higher in subjects immunized with DTwP-Local vaccine. Immunogenicity against diphtheria and tetanus was similar for the two vaccines, but immunogenicity of the local vaccine against pertussis was significantly less efficient than that of DTwP-Pasteur. This difference and the higher side effects of the DTwP-Local vaccine could be due to the bacterial strain or the preparation or formulation protocol of the local pertussis vaccine. Keywords:Diphtheria-tetanus-pertussis vaccine, vaccination, immunogenicity, reactogenicity, enzyme-linked immunosorbent assay, randomized controlled trial == Introduction == Whole cell pertussis vaccines combined with tetanus and diphtheria toxoid (DTwP) have (+)-CBI-CDPI2 been in use since 1950s in Iran. The national DTwP vaccination program consists of three primary doses given at 2, 4 and 6 mo of age, with a forth dose given at 18th month and a fifth dose, between 4 to six years of age. For coverage of pertussis vaccination, two different types of pertussis vaccine are currently available, the whole cell (wP) vaccine that was developed in the 1940s and the acellular (aP) vaccine. Both types of vaccine provide protection, though the wP vaccines are thought to induce more efficient immunity.1,2In spite of the universal vaccination programs against pertussis,Bordetella pertussisresumes to circulate even in (+)-CBI-CDPI2 populations with high vaccine coverage in infants and children.3This is evident from the current increase in pertussis incidence in adolescent and young adults,4,5who serve as an important reservoir of transmission of the pathogen. In Iran, the registered cases of diphtheria, tetanus and pertussis were 106,14 and 464 cases in 2010 2010 and 132,18 and 650 in 2011, respectively.6Although the benefit from the DTwP vaccine was established by previous studies,7-9however, periodic assessment of the vaccine is necessary for national vaccination programs which serves as the basis of systemic immunization policy.10,11Assessment of local vaccines is performed regularly based on the national regulations of the (+)-CBI-CDPI2 Food and Drug Administration of the Ministry of Health, Treatment and Medical Education of Iran. According to these regulations a randomized study needs to be performed to evaluate immunogenicity and reactogenicity of such vaccines. In the present study immunogenicity and reactogenicity of a DTwP vaccine manufactured locally (DTwP-Local) were compared with those Mouse monoclonal to Tyro3 induced by a commercial DTwP vaccine (DTwP-Pasteur) in a group of preschool Iranian children. == Results == == Demographic data == Among a total of 710 children who entered the study, 38 (5%) failed to continue the investigation (Fig. 1). The most common reason for withdrawal was refusal of the parents or the children to give blood samples. None of the participants withdrew due to side reactions to any of the vaccines. Demographic characteristics of the participants were similar between the groups (Table 1). Figure 1.CONSORT (Consolidated Standards of Reporting Trials) participant flow diagram. == Table 1.Demographic characteristics of the children vaccinated with either DTwP-Local or DTwP-Pasteur vaccine. == aChi-Square test;bt-test; NA: Not applicable == Immunogenicity == Before vaccination, there was no significant difference in the antibody titers against diphtheria, tetanus and pertussis between the subjects receiving the two vaccines (Table 2). After vaccination, the geometric mean titers (GMTs) of the antibodies induced against diphtheria and tetanus by DTwP-Local were 7.7 and 9.4 IU/ml and those of DTwP-Pasteur were 8.2 and 8.6 IU/ml, respectively (Table 2). There was no significant difference between the immunogenicity of the vaccines against diphtheria (power = 93%) and tetanus (power = 86%). The post-booster GMTs of antibodies produced against pertussis were 30.2 EU/ml for DTwP-Local and 47.9 EU/ml for DTwP-Pasteur vaccines, respectively (p < 0.001). Box plot presentation of antibody concentrations in pre- and post-booster samples is shown inFigure 2. Pre-booster seroprotection rates of pertussis were 25.2% and 31% which were raised to 70.3% and 85.7% upon immunization with DTwP-Local and DTwP-Pasteur vaccines, respectively (Table 2). Using the binary logistic regression analysis, no significant effect of sex, weight and birth weight on post-booster antibody.