Dose-sparing effect of two adjuvant formulations with a pandemic influenza A/H7N9 vaccine: A randomized, double-blind, placebo-controlled, phase 1 clinical trial.

The emergence of potentially pandemic viruses has resulted in preparedness efforts to develop candidate vaccines and adjuvant formulations. We evaluated the dose-sparing effect and safety of two distinct squalene-based oil-in-water adjuvant emulsion formulations (IB160 and SE) with influenza A/H7N9 antigen. This phase I, randomized, double-blind, placebo-controlled, dose-finding trial (NCT03330899), enrolled 432 healthy volunteers aged 18 to 59. Participants were randomly allocated to 8 groups: 1A) IB160 + 15µg H7N9, 1B) IB160 + 7.5µg H7N9, 1C) IB160 + 3.75µg H7N9, 2A) SE + 15µg H7N9, 2B) SE + 7.5µg H7N9, 2C) SE + 3.75µg H7N9, 3) unadjuvanted vaccine 15µg H7N9 and 4) placebo. Immunogenicity was evaluated through haemagglutination inhibition (HI) and microneutralization (MN) tests. Safety was evaluated by monitoring local and systemic, solicited and unsolicited adverse events (AE) and reactions (AR) 7 and 28 days after each study injection, respectively, whereas serious adverse events (SAE) were monitored up to 194 days post-second dose. A greater increase in antibody geometric mean titers (GMT) was observed in groups receiving adjuvanted vaccines. Vaccinees receiving IB160-adjuvanted formulations showed the greatest response in group 1B, which induced an HI GMT increase of 4.7 times, HI titers ≥40 in 45.2% of participants (MN titers ≥40 in 80.8%). Vaccinees receiving SE-adjuvanted vaccines showed the greatest response in group 2A, with an HI GMT increase of 2.5 times, HI titers ≥40 in 22.9% of participants (MN titers ≥40 in 65.7%). Frequencies of AE and AR were similar among groups. Pain at the administration site and headache were the most frequent local and systemic solicited ARs. The vaccine candidates were safe and the adjuvanted formulations have a potential dose-sparing effect on immunogenicity against influenza A/H7N9. The magnitude of this effect could be further explored.

Pharmacovigilance capacity strengthening for WHO prequalification: The case of the trivalent influenza vaccine manufactured by Instituto Butantan.

Instituto Butantan is a biomedical research center and vaccine manufacturer affiliated with the São Paulo State Secretary of Health in Brazil. In 2013, Instituto Butantan successfully licensed its trivalent influenza vaccine, in order to support the Brazilian National Immunization Program's influenza vaccination strategy, which was introduced in 1999. In order to respond to the increasing influenza vaccine demand worldwide, Instituto Butantan is undergoing prequalification of its trivalent influenza vaccine by the World Health Organization (WHO). A key requirement of the prequalification review was the submission of a pharmacovigilance plan, including an active surveillance evaluation, for the trivalent influenza vaccine, and proof of a functional pharmacovigilance system at Instituto Butantan. The aim of this paper is to describe the capacity strengthening process of the pharmacovigilance system at Instituto Butantan for the WHO prequalification of the trivalent influenza vaccine. This process was supported by PATH and the U.S. Federal Government Biomedical Advanced Research and Development Authority (BARDA). The key strategic axes for this capacity strengthening process included the improvement of organizational structure, human resources training, internal processes and procedures, appropriate documentation, and acquisition of an E2B compliant pharmacovigilance database. The project led to the establishment of a functional pharmacovigilance system compliant with international regulatory requirements.