Background/Objectives: Fractional intradermal administration may offer a dose-sparing approach to dengue vaccination. This randomized pilot study explored the administration of a fractional intradermal second dose of TAK-003 and described immune responses and adverse events in dengue-seropositive adults. Methods: Both groups received a standard 0.5-mL subcutaneous first dose, followed approximately 90 days later by either a standard 0.5-mL subcutaneous second dose or a fractional 0.1-mL intradermal second dose. Twenty-four dengue-seropositive adults were randomized in a 1:1 ratio to the SC–SC or SC–ID group. Anti-dengue IgG and IFN-γ ELISpot responses to DENV peptide pools were assessed at baseline, day 30, and day 120. Immunogenicity analyses were exploratory. Results: All 24 vaccinated participants completed follow-up. Day-30 measurements followed the common subcutaneous first dose and preceded the different second-dose regimens. At day 120, median anti-dengue IgG levels were 141.30 and 146.60 RU/mL in the SC–SC and SC–ID groups, respectively. IFN-γ responses to the tested peptide pools were measurable in both groups. No statistically significant between-group differences were detected at day 120, although the small sample size precludes conclusions of similarity. No serious adverse events were observed. Conclusions: Fractional intradermal administration of the second TAK-003 dose elicited measurable humoral and cellular immune responses and supports the biological feasibility of this dose-sparing approach. Given the exploratory nature and small sample size of this pilot study, these findings warrant confirmation in larger studies.

Background/Objectives: Achromobacter bacteremia is uncommon, difficult to treat and lacks historically consistent organism-specific susceptibility criteria. We described its clinical characteristics, antimicrobial exposure, susceptibility patterns, treatment, and outcomes over 20 years. Methods: We retrospectively reviewed adults with Achromobacter-positive blood cultures at a Thai tertiary-care hospital during 2006–2025. The first eligible episode per patient was used for patient-level analyses. Historical susceptibility categories were retained as reported. Available matched blood-isolate minimum inhibitory concentrations (MICs) were retrospectively interpreted using Clinical and Laboratory Standards Institute (CLSI) M100, 36th edition. Results: Forty-nine eligible episodes occurred in 47 patients, of which 43/47 (91.5%) were nosocomial. Prior systemic antibiotics and carbapenems had been received by 43/45 (95.6%) and 26/45 (57.8%) patients, respectively. Prior carbapenem exposure was associated with meropenem non-susceptibility (50.0% vs. 11.1%; odds ratio (OR) 7.64, p = 0.010). Thirty-day mortality was 23/46 (50.0%). Non-survivors had higher median National Early Warning Score (NEWS) than survivors (6 vs. 3; p = 0.005). Mortality was lower among patients receiving active than inactive empiric therapy (39.4% vs. 76.9%; OR 0.20, p = 0.047), but the association attenuated after adjustment for vasopressor use. Historical disk and contemporary MIC categories were not fully concordant in the small matched subset (n = 7). Conclusions: Achromobacter bacteremia occurred predominantly as a nosocomial infection in heavily antibiotic-exposed patients and was associated with high mortality. Prior carbapenem exposure was associated with meropenem non-susceptibility, while mortality was closely related to acute illness severity. Historical susceptibility results should be interpreted in the context of the testing method and breakpoint framework.