Itching nodules and aluminium allergy following vaccination with aluminium-adsorbed vaccines-Not a negligible problem

Cross-reactivity of hantavirus antibodies after immunization with PUUV antigens

Nephropathia epidemica (NE), caused by Puumala (PUUV) orthohantavirus, is endemic in the Republic of Tatarstan (RT). There are limited options for NE prevention in RT. Currently, available vaccines are made using Haantan (HNTV) orthohantavirus antigens. In this study, the efficacy of microvesicles (MVs) loaded with PUUV antigens to induce the humoral immune response in small mammals was analyzed. Additionally, the cross-reactivity of serum from immunized small mammals and NE patients with HNTV, Dobrava, and Andes orthohantaviruses was investigated using nucleocapsid (N) protein peptide libraries. Finally, the selected peptides were analyzed for allergenicity, their ability to induce an autoimmune response, and their interaction with Class II HLA. Several N protein peptides were found to be cross-reactive with serum from MVs immunized small mammals. These cross-reactive epitopes were located in oligomerization perinuclear targeting and Daxx-interacting domains. Most cross-reactive peptides lack allergenic and autoimmune reactivity. Molecular docking revealed two cross-reacting peptides, N6 and N19, to have good binding with three Class II HLA alleles. These peptides could be candidates for developing vaccines and therapeutics for NE.

Identification of conserved immunogenic peptides of SARS-CoV-2 nucleocapsid protein

The emergence of the new SARS-CoV-2 variants has led to major concern regarding the efficacy of approved vaccines. Nucleocapsid is a conserved structural protein essential for replication of the virus. This study focuses on identifying conserved epitopes on the nucleocapsid (N) protein of SARS-CoV-2. Using 510 unique amino acid sequences of SARS-CoV-2 N protein, two peptides (193 and 215 aa) with 90% conservancy were selected for T cell epitope prediction. Three immunogenic peptides containing multiple T cell epitopes were identified which were devoid of autoimmune and allergic immune response. These peptides were also conserved (100%) in recent Omicron variants reported in Jan-August 2023. HLA analysis reveals that these peptides are predicted as binding to large number of HLA alleles and 71-90% population coverage in six continents. Identified peptides displayed good binding score with both HLA class I and HLA class II molecules in the docking study. Also, a vaccine construct docked with TLR-4 receptor displays strong interaction with 20 hydrogen bonds and molecular simulation analysis reveals that docked complex are stable. Additionally, the immunogenicity of these N protein peptides was confirmed using SARS-CoV-2 convalescent serum samples. We conclude that the identified N protein peptides contain highly conserved and antigenic epitopes which could be used as a target for the future vaccine development against SARS-CoV-2.Communicated by Ramaswamy H. Sarma.

Computational design of immunogenic peptide constructs comprising multiple HLA restricted Dengue virus envelope epitopes

Dengue virus (DENV) is endemic in 100 countries with ability to impact nearly 50% of world population. DENV envelope (E) protein is responsible for viral attachment to host cells and has been target of various countermeasure development efforts. The current study focuses on a consensus computational approach to identify cross-reactive, immunogenic DENV-2 E peptides displaying promiscuity with a wide array of HLA molecules. Four conserved peptides (FP-1, FP-2, FP-3 and FP-4) containing multiple CD8⁺ and CD4⁺ T cell epitopes were identified by employment of various immunoinformatics tools. FP-1, FP-2, FP-3 and FP-4 were estimated to bind with 227, 1787, 1008 and 834 HLA alleles respectively. RMSD values obtained by Molecular docking (CABS-Dock) with 20 HLA alleles (10 each of HLA class I and II) resulted into comparable RMSD values of identified epitopes with native peptides which represents the natural presentation of epitopes to HLA molecules. These peptides were also found to be part of previous experimentally validated immunogenic peptides. Further, a dengue immunogenic peptide construct was generated by linking the four peptides, an adjuvant and a 6x histidine tag. The construct showed strong binding and stability with Toll-like receptor (TLR4). Collectively, these results provide strong evidence in the support of the immunogenic potential of the dengue immunogenic peptide construct. This article is protected by copyright. All rights reserved.

Widespread cutaneous eruption after aluminum-containing vaccination: A case report and review of current literature

Aluminum salts are adjuvants found in many vaccines. Although rare, patients have reported cutaneous reactions to aluminum salts including persistent pruritic subcutaneous nodules at the injection site. We report the case of an 11-year-old male who at the age of 5 years developed a generalized pruritic cutaneous eruption after receiving the aluminum-containing Quadracel^® vaccination. Patch testing at that time was positive to aluminum salts and again on repeat patch testing 6 years later. Our case highlights a delayed systemic cutaneous reaction to a vaccine containing aluminum salts. We review cutaneous allergic reactions to vaccines containing aluminum salts and vaccination advice for patients with aluminum contact allergy.