botulism+tetanus vaccine

Development and Humanization of a Camelid-Derived Neutralizing Nanobody Targeting Botulinum Neurotoxin Type A.

Jiang Yujia Y, Xin Wenwen W, Lu Jiansheng J, Wang Rong R et al.

Botulinum neurotoxin (BoNT), produced by Clostridium botulinum, is one of the most potent neurotoxins, causing botulism, a potentially fatal paralytic disease. Among different serotypes, BoNT/A is the most potent and the primary cause of botulism. The receptor-binding domain (Hc) of BoNT is crucial for targeting host cell receptors, making it a key therapeutic target. This study aims to develop neutralizing antibodies against BoNT/A by isolating camelid-derived nanobodies (Nbs) targeting BoNT/A-Hc (AHc). A panel of Nbs specifically targeting AHc was isolated from a camelid immune phage display library. The VHH fragments were fused with human IgG Fc (hFc) to generate VHH-hFc fusion proteins. Neutralizing activity was evaluated using a murine lethality assay following pre-incubation of antibody and toxin. Potent Nbs were humanized through homology modeling, which predicts a theoretically reduced risk of immunogenicity. The affinity of the parent and humanized antibodies to AHc was measured using biolayer interferometry (BLI). Their biophysical properties, including thermal stability and aggregation propensity, were assessed by differential scanning fluorimetry (DSF), static light scattering (SLS), and dynamic light scattering (DLS). Fifty-nine unique VHH clones were identified, four of which provided complete protection against a 20 LD50 BoNT/A challenge in mice. The most potent antibodies, 1A1 and 1A3, exhibited ED50 of 0.47 μg per mouse, corresponding to a neutralizing potency of 4.3 IU/mg. Upon humanization, the variants hA1 and hA3 showed strong binding affinities, with KD ranging from 1 to 2 nM. The humanized variant hA1 demonstrated superior neutralizing activity against BoNT/A, exhibiting an ED50 of 0.12 μg and a potency of 17.1 IU/mg, which represents an approximate four-fold increase compared to the parental antibody (1A1). Additionally, hA1 demonstrated enhanced thermal stability and minimal aggregation propensity. Humanized Nbs could serve as an attractive platform for developing novel botulism therapeutics, with potential advantages over traditional serum antitoxins in safety profile, clinical tolerability and scalable manufacturing. These favorable traits render them viable candidates for next-generation antitoxins against BoNT/A poisoning. Humanized Nb hA1 displays potent neutralizing activity and optimized biophysical properties, implying its value as a preclinical lead for botulism intervention. Nevertheless, systematic follow-up studies covering post-exposure protective efficacy, direct immunogenicity testing and comprehensive safety profiling are required to fully validate its translational prospects.

A bivalent oral yeast vaccine displaying Nocardia seriolae FHA and LMBV MCP confers protection in largemouth bass (Micropterus salmoides).

Lu Jianfei J, Gu Boge B, Yu Pengzhen P, Chen Jiong J

Largemouth bass ranavirus (LMBV) and Nocardia seriolae are major pathogens affecting largemouth bass (Micropterus salmoides), causing significant economic losses. In this study, recombinant yeasts expressing the fibronectin-binding protein A (FHA) of N. seriolae or the major capsid protein (MCP) of LMBV were constructed using the yeast surface display (YSD) system. Based on these recombinant strains, a bivalent oral yeast-based vaccine was developed and its protective efficacy was systematically evaluated. Oral administration of the vaccine induced specific antibodies against FHA and MCP in serum, as well as increased the transcription levels of adaptive immune genes (IgM, IgT, MHC-II) and innate immune genes (IL-1β, TNF-α, IFN-1, Mx2) in the hindgut, liver, and spleen. Importantly, the bivalent oral vaccine provided significant protection against both pathogens in largemouth bass, with relative percent survival (RPS) values of 56.7% against N. seriolae and 63.3% against LMBV. Meanwhile, the oral vaccine reduced pathogen loads and alleviated histopathological lesions. In summary, these findings suggest that the bivalent oral vaccine developed in this study could serve as a promising strategy for controlling N. seriolae and LMBV infections in largemouth bass aquaculture.

Genomic characterization of the attenuated human cytomegalovirus strain TR-VAC developed for subviral particle vaccine production.

Schmidt Hanno H, Hewel Charlotte C, Büscher Nicole N, Linke Matthias M et al.

We report the complete genome sequence of the attenuated human cytomegalovirus strain TR-VAC, developed for subviral particle vaccine production. Oxford Nanopore duplex sequencing confirmed all engineered modifications, including UL130 repair, UL25 stop codons, ddFKBP insertion, GFP deletion, and retention of the bacterial artificial chromosome backbone, without large-scale structural rearrangements.

Vaccine hesitancy in peripheral communities: Combating digital malpractice.

Siddiqui Gulnaz Fatima GF, Siddiqui Shahid Akhtar SA