Meningococcal group B vaccine(GlaxoSmithKline Biologicals SA)

Delonix Bioworks, a clinical-stage biotechnology company based in Shanghai and Perth, has initiated first-in-human dosing of the DX-104 vaccine, a MenB OMV vaccine candidate built on the company’s proprietary OMV Plus platform. As per a clinicaltrials.gov listing, the Phase I clinical trial is a randomized, double-blinded, positive-controlled study evaluating safety and immunogenicity in healthy adults in Perth, Australia. The enrollment target is 30 with participants to receive DX-104 or Bexsero at months 0, 1, and 6, with primary completion expected in May 2027. DX-104 uses genetically engineered outer membrane vesicles to present bacterial antigens, targeting serogroup B Neisseria meningitidis. The specific molecular antigens displayed on the OMVs have not been disclosed. The first-in-human DX-104 trial also serves as a platform validation event for the OMV Plus technology, which Delonix intends to apply across a broader pipeline including vaccines for pertussis, N. gonorrhoeae, and K. pneumoniae. Research context The scientific rationale for an OMV-based meningococcal B vaccine rests on decades of clinical and immunological evidence. Outer membrane vesicles derived from N. meningitidis contain native surface proteins in their natural conformation, stimulating bactericidal antibodies—the accepted correlate of protection against invasive meningococcal disease. Earlier OMV vaccines developed for outbreak control in Norway, Cuba, and New Zealand demonstrated strain-specific efficacy but limited breadth. Advances in genetic engineering now allow modification of OMVs to display optimized or additional antigens and reduce reactogenicity. This trajectory underpins the OMV Plus platform, though peer-reviewed data specific to DX-104’s engineered antigen composition are not yet available. The current standard of care for MenB prevention centers on two licensed vaccines: GSK’s Bexsero, a four-component vaccine combining recombinant proteins (fHbp, NadA, NHBA) with an OMV component, and Pfizer’s Trumenba, a bivalent recombinant fHbp vaccine. Both have been in use since the mid-2010s. More recently, the field has consolidated around pentavalent combination products: Pfizer’s Penbraya (approved October 2023) and GSK’s Penmenvy (approved February 2025) each combine MenB and MenACWY components into a single vaccination series for individuals aged 10–25. Despite commercial validation—Bexsero reported approximately USD 1.58 billion in 2025 sales—gaps persist. Strain coverage estimates for existing vaccines vary by region, ranging from roughly 60% to 91%. Manufacturing complexity contributes to per-dose costs that limit access in low- and middle-income countries, where meningococcal disease burden is concentrated. Adolescent MenB vaccination rates in the United States remain around 30%-35%, well below MenACWY uptake. The WHO’s “Defeating Meningitis by 2030” roadmap has called for broader access to affordable MenB vaccines. Competitive landscape DX-104 enters a field where no novel MenB vaccine candidates beyond the established GSK and Pfizer franchises appear to be in late-stage clinical development. Bexsero and Trumenba remain the only MenB-specific vaccines with active clinical programs, primarily consisting of post-marketing and life-cycle management studies. An earlier nine-valent OMV vaccine (NonaMen, Norwegian Institute of Public Health) targeting multiple PorA subtypes completed early trials but is not currently recruiting. Regional outbreak-response OMV vaccines such as MeNZB and VA-MENGOC-BC are no longer in active development. The absence of clinical-stage competitors pursuing new OMV-based or recombinant MenB approaches means DX-104 occupies a relatively uncrowded space for a next-generation candidate, though it faces a long development timeline against entrenched products with extensive real-world evidence. The differentiation Delonix claims—broader strain coverage, simplified manufacturing, and lower cost—will require clinical data to substantiate. The company has not disclosed which antigens are engineered into its OMVs, making it difficult to assess immunological differentiation from Bexsero’s existing OMV component. Your email address will not be published. Required fields are marked * Comment * Name * Email * Website

FRIDAY, March 20, 2026 — A meningitis vaccine does not protect against gonorrhea spread between men, a new clinical trial has concluded. Experts had hoped that a meningococcal B vaccine called 4CMenB might prevent the spread of gonorrhea, based on an earlier study that linked the vaccine to a 38% reduced risk of the sexually transmitted infection. But a clinical trial designed to prove this effect instead found that gonorrhea rates were the same between men who got either the vaccine or a placebo jab, researchers reported at a Conference on Retroviruses and Opportunistic Infections held in Denver. “Across both arms, the gonorrhea incidence was virtually the same – at around 48% per year, indicating very clearly that the vaccine had no effect on preventing gonorrhea,” lead researcher Kate Seib , a professor at Griffith University in Australia, said in a news release. The results “provide strong evidence that the 4CMenB meningococcal vaccine is not effective at preventing gonorrhea in gay and bisexual men who are at high risk of contracting it,” Seib concluded. There remains no vaccine to protect against gonorrhea, researchers said. Antibiotic-resistant strains of gonorrhea have started to emerge, increasing the need for a vaccine. For the study, researchers recruited 654 men who have sex with other men, and the primary analysis included 587. Half were randomly assigned to receive the meningococcal vaccine and the other half a placebo. Tracking across two years showed that the vaccinated men had the same odds of contracting gonorrhea as those who’d gotten the placebo. Researchers suspect that the earlier study’s results likely were confounded by other factors not related to the vaccine. “An effective vaccine to reduce gonorrhea would transform our approach to prevention, so it is incredibly disappointing that our research has proven that 4CMenB is not effective in gonorrhea prevention in gay and bisexual men,” said researcher Andrew Grulich , a professor at the Kirby Institute at the University of New South Wales in Australia. “We want men who have received the 4CMenB vaccine in the hope of gonorrhea prevention to know that the vaccine is very safe and they will have protection against some meningococcal strains,” Grulich said in a news release. “However, these men will need to explore other options for prevention of acquisition of gonorrhea, such as condoms and regular testing.” Seib presented these findings on Feb. 25 at the scientific meeting in Denver. Findings presented at medical meetings should be considered preliminary until published in a peer-reviewed journal. Sources University of New South Wales, news release, Feb. 25, 2026