Phase I safety and immunogenicity study of a Brazilian serogroup B vaccine

Meningococcal disease by serogroup B has been a public health problem in Brazil in the last decades. The Brazilian Oswaldo Cruz Foundation has been working to develop a vaccine with detergent-treated outer membrane vesicles (OMV) and detoxified endotoxin (dLOS) from Neisseria meningitidis serogroup B prevalent strains. A phase I study, enrolling 26 adults (18–44 years of age) was performed using experimental vaccines combining B components and aluminum hydroxide as adjuvant. It was a dose escalation study testing vaccines made of 25, 50, and 100 µg OMV protein/mL (sum of both strains) and dLOS in half amount of total protein concentration, with three doses given two months apart. Adverse events were mild/moderate with frequency increasing with the amount of antigens. Pain in the site of injection was the most frequent reaction in all doses, reported in more than the 85% across vaccine groups. Considering all injections, cephalea was the most common systemic adverse event, detected in 11.1%, 17.2% and 32.1%, respectively with doses of 12.5 μg, 25 μg and 50 μg. High titers of total IgG (ELISA) were observed for the vaccine components before vaccination. Protective levels of bactericidal antibodies (titer ≥1:4) for both vaccine strains were also present. Considering a 4-fold increase of IgG titers compared to pre-immune values (seroconversion), 50%-70% of those who received intermediate and highest doses of antigens presented satisfactory response for OMV of N44/89 strain. The lowest dose vaccine induced no seroconversion for strain N44/89, and 11% for strain N603/95. For the three vaccines doses, 25% of seroconversion, in total IgG against LOS, was observed. Increased antibody bactericidal activity was observed for both strains in higher antigen concentrations. For IgG against LOS, all vaccine formulations showed 25% of seroconversion. In conclusion, MenB-Bio experimental vaccines were well tolerated and immunogenic, thus allowing phase II studies.

Knowledge, use, and disuse of unconventional food plants

BACKGROUND

People's diets are usually restricted to a small number of plant species, even in regions with great diversity. We investigated the knowledge of residents in Ribeirão da Ilha, a district of Florianópolis (Santa Catarina, Brazil), about unconventional food plants (UFP). We report the UFP of the region, the parts used, the methods of processing, and the reasons for reduced use or even lack of use.

METHODS

From June 2014 to January 2015, we interviewed 26 long-established residents and made free listings of plant resources in the region. We also did three guided tours, and 24 residents (among the 26) checked pictures of the mentioned plants in order to identify them.

RESULTS

We identified 63 species distributed in 25 botanical families. Half of the species were mentioned only by one informant. The fruit was the most frequently used part (80% of citations), consumed mainly without processing. Among those species, 27% were used exclusively in the past. The residents attributed non-use to the difficulty in locating the plants and loss of interest in the resource.

CONCLUSION

Urbanization and environmental restrictions contribute to the difficulty of access to UFP. Encouraging residents to continue using UFP is necessary to perpetuate this threatened knowledge, promote a more diversified and healthier diet, stimulate a greater interaction among people and nature, and promote on farm conservation of edible plants.

Characterization and immunogenicity of meningococcal group C conjugate vaccine prepared using hydrazide-activated tetanus toxoid

The steps to produce, purify and control an immunogenic Brazilian conjugate vaccine against group C meningococcus (MenCPS-TT) using hydrazide-activated tetanus toxoid were developed. The conjugation methodology reduced the reaction time easily allowing scale-up. One freeze-dried pilot vaccine lot purified by tangential filtration, showed satisfactory quality control results including safety and stability. The pilot vaccine was immunogenic in mice in a dose-dependent fashion generating a 10-20-fold rise in IgG response in mice. The vaccine also induced high bactericidal titers. Vaccine concentrations of 1 and 0.1 microg showed higher avidity indices, suggesting induction of immunologic memory. These results support initiation of Phase I clinical studies with the MenCPS-TT conjugate vaccine.

Study on thermostabilizers for trivalent oral poliomyelitis vaccine

Different formulations of Trivalent Oral Poliomyelitis Vaccine were tested, in order to obtain better thermostability, reduce corrosion of machinery and improve production costs. Magnesium chloride, sucrose, arginine and 199-Hank's medium were used in the formulations. The most appropriate formulation was a mixture of MgCl2 and arginine, which was highly thermostable, and had low production costs.