Immunological non-inferiority of a new fully liquid presentation of the MenACWY-CRM vaccine to the licensed vaccine: results from a randomized, controlled, observer-blind study in adolescents and young adults

A fully liquid MenACWY-CRM vaccine presentation has been developed, modifying the meningococcal serogroup A (MenA) component from lyophilized to liquid. The safety and immunogenicity of the liquid presentation at the end of the intended shelf-life (aged for 24 or 30 months) were compared to the licensed lyophilized/liquid presentation. This multicenter, randomized (1:1), observer-blind, phase 2b study (NCT03433482) enrolled adolescents and young adults (age 10-40 years). In part 1, 844 participants received one dose of liquid presentation stored for approximately 24 months or licensed presentation. In part 2, 846 participants received one dose of liquid presentation stored for approximately 30 months or licensed presentation. After storage, the MenA free saccharide (FS) level was approximately 25% and O-acetylation was approximately 45%. The primary objective was to demonstrate non-inferiority of the liquid presentation to licensed presentation, as measured by human serum bactericidal assay (hSBA) geometric mean titers (GMTs) against MenA, 1-month post-vaccination. Immune responses against each vaccine serogroup were similar between groups. Between-group ratios of hSBA GMTs for MenA were 1.21 (part 1) and 1.11 (part 2), with two-sided 95% confidence interval lower limits (0.94 and 0.87, respectively) greater than the prespecified non-inferiority margin (0.5), thus meeting the primary study objective. No safety concerns were identified. Despite reduced O-acetylation of MenA and increased FS content, serogroup-specific immune responses induced by the fully liquid presentation were similar to those induced by the licensed MenACWY-CRM vaccine, with non-inferior anti-MenA responses. The safety profiles of the vaccine presentations were similar.

Atypical SARS in geriatric patient

We describe an atypical presentation of severe acute respiratory syndrome (SARS) in a geriatric patient with multiple coexisting conditions. Interpretation of radiographic changes was confounded by cardiac failure, with resolution of fever causing delayed diagnosis and a cluster of cases. SARS should be considered even if a contact history is unavailable, during an ongoing outbreak.

Community-acquired legionellosis in Singapore

Patients admitted to hospital with chest infections were examined serologically to see if these were due to Legionella pneumophila. Each of the 219 samples of serum collected from 177 patients was examined by two standard tests. The tests, which generally agreed, identified three individuals (1.7% of the group) who had sufficient antibody to suggest that they were suffering from current legionellosis. Serological evidence of previous infection was discovered (with differing degrees of certainty) in 26 (14.7%) of the others. The study showed that legionellosis is endemic in Singapore, and so must be taken into account in the differential diagnosis of cases of pneumonia.

Pulmonary sarcoidosis in Singapore

Eight cases of pulmonary sarcoidosis with a mean age of 27.8 years were seen in our Department since May 1974. There were 5 males and 3 females and 5 of our patients were Chinese. 75% of cases were symptomatic at initial presentation. Extra pulmonary manifestation was seen in only one patient who had a right facial palsy. Hilar adenopathy was the principal radiological finding. (Bilateral hilar adenopathy was present in 6 and unilateral hilar adenopathy was seen in 1 patient) 50% of our patients had x-ray evidence of pulmonary parenchymal involvement and received steroid therapy. Though sarcoidosis is rare among Asians especially among Chinese, we feel an increase in prevalence can be expected in future.