The various other authors haven’t any conflicts appealing to disclose. Data sharing statement: Qualified researchers may request access to patient-level data and related study documents including the clinical study report, study protocol, blank case report form, statistical analysis plan and Cephalexin monohydrate dataset specifications. Results: Among 688 randomized participants, 629 (91.4%) were baseline dengue seropositive (concomitant group, n = 314 and sequential group, n = 315). After the first dose, non-inferiority of immune responses between concomitant and sequential vaccination was achieved; between-group geometric mean antibody concentration ratios were close to 1 for anti-PT, anti-FHA, anti-PRN and anti-FIM, between-group differences in percent achieving seroprotection (titers 0.1 IU/mL) were 0.26% (diphtheria) and 0.66% (tetanus), and between-group geometric mean antibody titer ratios were close to 1 for dengue serotypes 1C4. Safety profiles in both study groups were comparable. Conclusions: CYD-TDV and Tdap vaccine administered Cephalexin monohydrate concomitantly or sequentially in baseline dengue seropositive participants elicited comparable immunogenicity and safety profiles. Keywords: dengue vaccine, immunogenicity, Philippines, Tdap vaccine, safety IMPORTANCE In dengue-endemic countries, integrating the dengue vaccine with national childhood immunization programs could help increase dengue vaccine coverage. The immunogenicity profiles of the combined tetanus toxoid (TT), reduced diphtheria toxoid (DT) and acellular pertussis (Tdap) vaccine and a tetravalent dengue vaccine (CYD-TDV) were unaffected when co-administered, either concomitantly or sequentially, in healthy participants between 9 and 60 years of age. Our study results demonstrate the feasibility of co-administration of CYD-TDV and Tdap without compromising the immunogenicity or safety of either vaccine. This could facilitate integrating the dengue vaccination schedule with preexisting national Tdap immunization programs in dengue-endemic countries. Dengue ranges from moderate, self-limiting disease resolving within 7C10 days, to severe dengue hemorrhagic fever and dengue shock syndrome, which lead to the hospitalization of an estimated 500,000 people/year and about 22,000 deaths/year worldwide.1,2 The annual global incidence of dengue infections (asymptomatic and symptomatic) was estimated to be 390 million in 2018, of which 70% were in South-East Asia and Western Pacific regions.3 However, in 2019, an unprecedented increase in dengue symptomatic cases was reported, with over 2,000,000 cases recorded in Brazil,4 and about 420,000 in the Philippines.5 Preventive measures, such as vector control Cephalexin monohydrate and personal protection to prevent transmission are limited in efficacy. A safe and effective vaccine against all 4 dengue serotypes is considered the best method of prevention.6 The CYD-TDV (Dengvaxia; Sanofi Pasteur, Swiftwater, PA) is usually a live-attenuated, chimeric vaccine.7,8 The efficacy and safety of a 3-dose series was assessed in phase IIb and phase III studies,9C11 and a retrospective analysis of the inferred serostatus of participants at the time of vaccination concluded that CYD-TDV protected against severe or hospitalized virologically-confirmed dengue (VCD) among baseline dengue seropositive participants, but not seronegative participants, who had a higher risk of developing severe dengue.12 The World Health Organization recommends that CYD-TDV should be used in individuals living in dengue-endemic regions with evidence of previous dengue infection.13 Pertussis, tetanus and diphtheria are major health concerns globally.14C16 Diphtheria (D) toxoid, tetanus (T) toxoid and pertussis (P) antigens have been combined to develop a range of combination vaccines; Cephalexin monohydrate with DTwP (whole-cell pertussis), DTaP (acellular pertussis) and DT vaccines, for children <7 years, and Tdap and Td for individuals 7 years.17 Co-administration of vaccines is perceived as an efficient strategy to introduce new vaccines to immunization schedules; however, supporting safety and immunogenicity data may be limited or inconclusive.18 Given the severe impact on public health of dengue, diphtheria, tetanus and pertussis infections, co-administration of Rabbit Polyclonal to BAD (Cleaved-Asp71) CYD-TDV with Tdap could facilitate the implementation of a school-based dengue vaccination program in those 9 years old in dengue-endemic countries. This study investigated the immunogenicity and safety of CYD-TDV when administered either concomitantly or sequentially with a booster dose of Tdap. MATERIALS AND METHODS Design and Participants This was a phase IIIb, randomized, open-label, multicenter non-inferiority trial of the immunogenicity and safety of concomitant or sequential administration of CYD-TDV and Tdap vaccines in healthy participants 9C60 years of age in the Philippines (NCT02992418). The study was conducted between December 2016 and December 2019. Inclusion criteria were: 9C60 years of age, healthy and receipt of at least 4 previous doses of DTaP vaccine (participants 9C11 years of age) or at least 3 previous doses of DTwP vaccine (participants 12 years of age), with the last dose of either vaccine not within 5 years of enrolment. Exclusion criteria included: being pregnant or lactating or.