Compliance with recommended vaccinations for Indian infants is facilitated by using combination vaccines to minimize the number of required injections. The ready-to-use, preservative free, fully-liquid combination DTwP-HepB-Hib vaccine, Quinvaxem(®), offers convenience of administering five important vaccine antigens to infants in a single injection. This phase III, single-arm, multicenter study was designed to assess immunogenicity and safety of three doses of Quinvaxem(®) to Indian infants administered at 6, 10, and 14 weeks of age. Blood samples were taken prior to the first dose and at one month post last vaccination. Infants were observed clinically for any reaction approximately 30 min following each vaccination, and parents completed subject diaries for solicited local, systemic and any adverse events (AEs) following over a 5 d period. DTwP-HepB-Hib vaccine elicited strong immune responses that exceeded seroprotection/seroconversion thresholds against all vaccine antigens. At one month after third vaccination, percentages of infants achieving predefined protective antibody levels were 99% diphtheria; 100% tetanus; 98% Hepatitis B; 100% Hib short-term (≥ 0.15 µg/mL); 95% Hib long-term (≥ 1.0 µg/mL) protection; and relevant immune response was 99% for pertussis. The vaccine was well tolerated, with no vaccine-related serious AEs. Only one case of high fever (≥ 40 °C) was reported. The most frequently reported reactions were mild to moderate tenderness and erythema. Frequencies of all AEs declined with subsequent vaccinations. This study demonstrated that this convenient, fully-liquid DTwP-HepB-Hib vaccine is highly immunogenic and has a acceptable safety profile for use in Indian infants. ClinicalTrials.gov Identifier: NCT01470287. Clinical Trials Registry of India Number: CTRI/2011/11/002118.
Keywords: DTwP–HepB–Hib; Immunogenicity; Safety; combination vaccine; fully-liquid pentavalent vaccine; infants.