Safety assessment of adjuvanted vaccines: Methodological considerations.

Adjuvants mainly interact with the innate immune response and are used to enhance the quantity and quality of the downstream adaptive immune response to vaccine antigens. Establishing the safety of a new adjuvant-antigen combination is achieved through rigorous evaluation that begins in the laboratory, and that continues throughout the vaccine life-cycle. The strategy for the evaluation of safety pre-licensure is guided by the disease profile, vaccine indication, and target population, and it is also influenced by available regulatory guidelines. In order to allow meaningful interpretation of clinical data, clinical program methodology should be optimized and standardized, making best use of all available data sources. Post-licensure safety activities are directed by field experience accumulated pre- and post-licensure clinical trial data and spontaneous adverse event reports. Continued evolution of safety evaluation processes that keep pace with advances in vaccine technology and updated communication of the benefit-risk profile is necessary to maintain public confidence in vaccines.

Efficacy of pneumococcal nontypable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) in young Latin American children: A double-blind randomized controlled trial.

BACKGROUND: The relationship between pneumococcal conjugate vaccine-induced antibody responses and protection against community-acquired pneumonia (CAP) and acute otitis media (AOM) is unclear. This study assessed the impact of the ten-valent pneumococcal nontypable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) on these end points. The primary objective was to demonstrate vaccine efficacy (VE) in a per-protocol analysis against likely bacterial CAP (B-CAP: radiologically confirmed CAP with alveolar consolidation/pleural effusion on chest X-ray, or non-alveolar infiltrates and C-reactive protein ≥ 40 µg/ml); other protocol-specified outcomes were also assessed. METHODS AND FINDINGS: This phase III double-blind randomized controlled study was conducted between 28 June 2007 and 28 July 2011 in Argentine, Panamanian, and Colombian populations with good access to health care. Approximately 24,000 infants received PHiD-CV or hepatitis control vaccine (hepatitis B for primary vaccination, hepatitis A at booster) at 2, 4, 6, and 15-18 mo of age. Interim analysis of the primary end point was planned when 535 first B-CAP episodes, occurring ≥2 wk after dose 3, were identified in the per-protocol cohort. After a mean follow-up of 23 mo (PHiD-CV, n = 10,295; control, n = 10,201), per-protocol VE was 22.0% (95% CI: 7.7, 34.2; one-sided p = 0.002) against B-CAP (conclusive for primary objective) and 25.7% (95% CI: 8.4%, 39.6%) against World Health Organization-defined consolidated CAP. Intent-to-treat VE was 18.2% (95% CI: 5.5%, 29.1%) against B-CAP and 23.4% (95% CI: 8.8%, 35.7%) against consolidated CAP. End-of-study per-protocol analyses were performed after a mean follow-up of 28-30 mo for CAP and invasive pneumococcal disease (IPD) (PHiD-CV, n = 10,211; control, n = 10,140) and AOM (n = 3,010 and 2,979, respectively). Per-protocol VE was 16.1% (95% CI: -1.1%, 30.4%; one-sided p = 0.032) against clinically confirmed AOM, 67.1% (95% CI: 17.0%, 86.9%) against vaccine serotype clinically confirmed AOM, 100% (95% CI: 74.3%, 100%) against vaccine serotype IPD, and 65.0% (95% CI: 11.1%, 86.2%) against any IPD. Results were consistent between intent-to-treat and per-protocol analyses. Serious adverse events were reported for 21.5% (95% CI: 20.7%, 22.2%) and 22.6% (95% CI: 21.9%, 23.4%) of PHiD-CV and control recipients, respectively. There were 19 deaths (n = 11,798; 0.16%) in the PHiD-CV group and 26 deaths (n = 11,799; 0.22%) in the control group. A significant study limitation was the lower than expected number of captured AOM cases. CONCLUSIONS: Efficacy was demonstrated against a broad range of pneumococcal diseases commonly encountered in young children in clinical practice. TRIAL REGISTRATION: www.ClinicalTrials.gov NCT00466947.

Primary vaccination with the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) in infants in Mali and Nigeria: a randomized controlled trial.

BACKGROUND: Pneumonia is still the leading cause of death among children in Africa, and pneumococcal serotypes 1 and 5 are frequently isolated from African children with invasive pneumococcal disease below the age of 5 years. The immunogenicity, safety and reactogenicity of 3-dose primary vaccination with the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) were evaluated in infants in Mali and Nigeria. METHODS: In an open, randomized, controlled study, 357 infants received DTPw-HBV/Hib and OPV primary vaccination with (PHiD-CV group) or without (control group) PHiD-CV co-administration at 6, 10 and 14 weeks of age. Pneumococcal antibody responses and opsonophagocytic activity (OPA) were measured and adverse events (AEs) recorded. RESULTS: One month post-dose 3, ≥ 97.2% of PHiD-CV-vaccinated infants had an antibody concentration ≥ 0.2 µg/mL for each vaccine pneumococcal serotype except for 6B (82.0%) and 23F (87.6%) versus < 10% in the control group except for serotypes 14 (35.7%) and 19F (22.5%). For each vaccine serotype, ≥ 93.3% of PHiD-CV recipients had an OPA titre ≥ 8, except for serotypes 1 (87.6%) and 6B (85.4%), compared to < 10% in the control group, except for serotypes 7F (42.9%), 9V (24.1%) and 14 (24.5%). Anti-protein D geometric mean antibody concentrations were 3791.8 and 85.4 EL.U/mL in the PHiD-CV and control groups, respectively. Overall incidences of solicited and unsolicited AEs were similar between groups. CONCLUSIONS: In sub-Saharan African infants, PHiD-CV was immunogenic for all vaccine pneumococcal serotypes and protein D. Vaccine tolerability was generally comparable between the PHiD-CV and control groups. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00678301.