Explore the vast range of titles available.

Neisseria meningitidis causes most cases of bacterial meningitis. Meningococcal meningitis is a public health burden to both developed and developing countries throughout the world. There are a number of vaccines (polysaccharide-based, glycoconjugate, protein-based and combined conjugate vaccines) that are approved to target five of the six disease-causing serogroups of the pathogen. Immunization strategies have been effective at helping to decrease the global incidence of meningococcal meningitis. Researchers continue to enhance these efforts through discovery of new antigen targets that may lead to a broadly protective vaccine and development of new methods of homogenous vaccine production. This review describes current meningococcal vaccines and discusses some recent research discoveries that may transform vaccine development against N. meningitidis in the future.

In February 2022, NVX-CoV2373 became available in South Korea; real-world effectiveness of multiple doses compared with mRNA-based vaccines has not been thoroughly evaluated. This retrospective study identified NVX-CoV2373 and BNT162b2 recipients aged ≥12 years from the K-COV-N database. Vaccine groups were propensity score–matched based on demographic characteristics, Seoul capital area residence, income level, comorbidity/disability, prior SARS-CoV-2 infection, and prior vaccination dose/timing. Outcomes were any and severe (intensive-care-unit admission or death within 8 weeks of infection) laboratory-confirmed SARS-CoV-2 infection assessed from 7 days after the third and fourth dose. Adjusted hazard ratios (aHRs) from matched groups measured vaccine effectiveness up to a 180-day risk window. From February to December 2022, 923,833 NVX-CoV2373 and 1,286,604 BNT162b2 doses were administered. The 180-day risk-window aHRs (95% CI) for NVX-CoV2373 compared with BNT162b2 for any SARS-CoV-2 infection were 0.78 (0.76–0.79) post third dose and 0.86 (0.86–0.87) post fourth dose. The 180-day aHRs (95% CI) for severe infection were 0.73 (0.53–1.00) after the third dose and 1.21 (1.03–1.42) after the fourth dose. NVX-CoV2373 demonstrated favorable and similar effectiveness against any and severe SARS-CoV-2 infection, respectively, compared with BNT162b2, with evidence of enhanced NVX-CoV2373 durability. •This is the largest cohort used in a real-world assessment on NVX-CoV2373 effectiveness to date.•NVX-CoV2373 compared favorably to BNT162b2 for lab-confirmed SARS-CoV-2 infection.•The two vaccines had comparable vaccine effectiveness against severe disease.•Relative effectiveness of NVX-CoV2373 versus BNT162b2 appeared to improve over time after 3rd and 4th dose administered.

The HIPRA-HH-2 was a multicentre, randomized, active-controlled, double-blind, non-inferiority phase IIb clinical trial comparing the immunogenicity and safety of the PHH-1V adjuvanted recombinant vaccine as a heterologous booster against homologous booster with BNT162b2. Interim results demonstrated strong humoral and cellular immune response against the SARS-CoV-2 Wuhan-Hu-1 strain and the Beta, Delta, and Omicron BA.1 variants up to day 98 post-dosing. Here we report that these responses with PHH-1V are sustained up to 6 months, including in participants over 65 years, despite their smaller sample size. The PHH-1V booster was non-inferior in eliciting neutralizing antibodies for SARS-CoV-2 Omicron XBB.1.5 variant compared to BNT162b2 after 6 months. No severe COVID-19 cases occurred in any group, and mild cases were similar (50.4 % for PHH-1V vs. 47.8 % for BNT162b2). While both groups may have reached comparable immunity levels, these findings suggest that the PHH-1V vaccine provides long-lasting immunity against various of SARS-CoV-2 variants. ClinicalTrials.gov Identifier: NCT05142553

•COVID-19 vaccine hesitancy persists, despite safe and effective approved vaccines.•Protein-based vaccines have been approved for use in the US since 1986.•Several protein-based vaccines against COVID-19 are authorized globally.•Protein-based COVID-19 vaccines could help improve vaccine uptake by offering another choice.

Because vaccine development is a difficult process, this study reviews aspects of phages as vaccine delivery vehicles through a literature search. The results demonstrated that because phages have adjuvant properties and are safe for humans and animals, they are an excellent vaccine tool for protein and epitope immunization. The phage genome can easily be manipulated to display antigens or create DNA vaccines. Additionally, they are easy to produce on a large scale, which lowers their manufacturing costs. They are stable under various conditions, which can facilitate their transport and storage. However, no medicine regulatory agency has yet authorized phage-based vaccines despite the considerable preclinical data confirming their benefits. The skeptical perspective of phages should be overcome because humans encounter bacteriophages in their environment all the time without suffering adverse effects. The lack of clinical trials, endotoxin contamination, phage composition, and long-term negative effects are some obstacles preventing the development of phage vaccines. However, their prospects should be promising because phages are safe in clinical trials; they have been authorized as a food additive to avoid food contamination and approved for emergency use in phage therapy against difficult-to-treat antibiotic-resistant bacteria. Therefore, this encourages the use of phages in vaccines.

During COVID-19 pandemic, international pharmaceutical companies put effort to build global manufacturing networks for vaccines. Soberana Plus vaccine, a recombinant protein based vaccine (RBD dimer), with the trade name of PastoCovac Plus in Iran, is based on a protein subunit platform in Cuba and completed preclinical and toxicological assessments. This study aimed at presenting the steps of vaccine technology transfer from Cuba to Iran. This study provides the first practical comparability results in Iran to ensure the quality, safety and efficacy of a protein subunit vaccine against COVID-19 after a successful technology transfer from Cuba. PastoCovac Plus was transferred to Iran at the formulation stage. The assessment of the active ingredient pharmaceutical (API) was achieved through physicochemical and clinical data collection and tests to assure if there was any adverse impact on the vaccination results. In order to assess the quality of the vaccine product after technology transfer, we sought different properties including regulatory features, physicochemical quality, vaccine potency and stability as well as its immunogenicity and safety. Following the evaluation of the clinical quality attributes (CQAs) based on the standard protocols, the results showed that the two vaccines are highly similar and comparable, with no considerable effect on safety or efficacy profiles. The CQAs were all in the acceptance limits in terms of safety and efficacy as well as clinical evaluation results. The immunogenicity evaluation also confirmed no significant differences between the vaccines regarding reinfection ( P = 0.199 ) or vaccine breakthrough ( P = 0.176 ). Furthermore, the level of anti-spike and neutralizing antibodies in the both vaccine groups was not significantly different indicating the equality of performance between the two vaccines. According to the results of the quality and clinical assessment of this study, we achieved an acceptable quality attributes and acceptant limits in terms of safety and efficacy of the vaccines pre and post technology transfer.

In this article we discuss characteristics of fusion protein-based SARS-CoV-2 vaccines. We focus on recombinant vaccine antigens comprising fusion proteins consisting of combinations of SARS-CoV-2-derived antigens or peptides or combinations of SARS-CoV-2 antigens/peptides with SARS-CoV-2-unrelated proteins/peptides. These fusion proteins are made to increase the immunogenicity of the vaccine antigens and/or to enable special targeting of the immune system. The protein-based vaccine approach is exemplified solely in a proof of concept study by using W-PreS-O, a chimeric vaccine based on a single fusion protein (W-PreS-O), combining RBDs from Wuhan hu-1 wild-type and Omicron BA.1 with the hepatitis B virus (HBV)-derived PreS surface antigen adsorbed to aluminum hydroxide. The W-PreS-O vaccine was evaluated in Syrian hamsters which were immunized three times at three-week intervals with W-PreS-O or with aluminum hydroxide (placebo) before they were infected with Omicron BA.1. Neutralizing antibody (nAB) titers, weight, lung symptoms, and viral loads, as measured using RT-PCR in the upper and lower respiratory tracts, were determined. In addition, infectious virus titers from the lungs were measured using a plaque-forming assay. We found that W-PreS-O-vaccinated hamsters developed robust nABs against Omicron BA.1, showed almost no development of pneumonia, and had significantly reduced infectious virus titers in the lungs. Importantly, the viral loads in the nasal cavities of W-PreS-O-vaccinated hamsters were close to or above the PCR cycle threshold considered to be non-infectious. The data of our proof-of-concept study provides compelling evidence that the W-PreS-O vaccine has protective effect against Omicron BA.1 in a Syrian hamster in vivo infection model and thus support the promising results obtained also for other fusion protein-based SARS-CoV-2 vaccines.

Background Streptococcus pneumoniae is the leading reason for invasive diseases including pneumonia and meningitis, and also secondary infections following viral respiratory diseases such as flu and COVID-19. Currently, serotype-dependent vaccines, which have several insufficiency and limitations, are the only way to prevent pneumococcal infections. Hence, it is plain to need an alternative effective strategy for prevention of this organism. Protein-based vaccine involving conserved pneumococcal protein antigens with different roles in virulence could provide an eligible alternative to existing vaccines. Methods In this study, PspC, PhtD and PsaA antigens from pneumococcus were taken to account to predict B-cell and helper T-cell epitopes, and epitope-rich regions were chosen to build the construct. To enhance the immunogenicity of the epitope-based vaccine, a truncated N-terminal fragment of pneumococcal endopeptidase O (PepO) was used as a potential TLR2/4 agonist which was identified by molecular docking studies. The ultimate construct was consisted of the chosen epitope-rich regions, along with the adjuvant role (truncated N-PepO) and suitable linkers. Results The epitope-based vaccine was assessed as regards physicochemical properties, allergenicity, antigenicity, and toxicity. The 3D structure of the engineered construct was modeled, refined, and validated. Molecular docking and simulation of molecular dynamics (MD) indicated the proper and stable interactions between the vaccine and TLR2/4 throughout the simulation periods. Conclusions For the first time this work presents a novel vaccine consisting of epitopes of PspC, PhtD, and PsaA antigens which is adjuvanted with a new truncated domain of PepO. The computational outcomes revealed that the suggested vaccine could be deemed an efficient therapeutic vaccine for S. pneumoniae ; nevertheless , in vitro and in vivo examinations should be performed to prove the potency of the candidate vaccine.

The World Health Organization (WHO) herald of the “End TB Strategy” has defined goals and targets for tuberculosis prevention, care, and control to end the global tuberculosis endemic. The emergence of drug resistance and the relative dreadful consequences in treatment outcome has led to increased awareness on immunization against Mycobacterium tuberculosis (Mtb). However, the proven limited efficacy of Bacillus Calmette-Guérin (BCG), the only licensed vaccine against Mtb, has highlighted the need for alternative vaccines. In this review, we seek to give an overview of Mtb infection and failure of BCG to control it. Afterward, we focus on the protein- and peptide-based subunit vaccine subtype, examining the advantages and drawbacks of using this design approach. Finally, we explore the features of subunit vaccine candidates currently in pre-clinical and clinical evaluation, including the antigen repertoire, the exploited adjuvanted delivery systems, as well as the spawned immune response.

[Display omitted] •Development of protein-based vaccines for LIV infection.•VLPs elicit potent neutralizing antibodies targeting multimers of viral E protein.•VLPs represent a promising platform for a LIV vaccine. Louping ill virus (LIV) is a tick-borne flavivirus that predominantly causes disease in livestock, especially sheep in the British Isles. A preventive vaccine, previously approved for veterinary use but now discontinued, was based on an inactivated whole virion that likely provided protection by induction of neutralizing antibodies recognizing the viral envelope (E) protein. A major disadvantage of the inactivated vaccine was the need for high containment facilities for the propagation of infectious virus, as mandated by the hazard group 3 status of the virus. This study aimed to develop high-efficacy non-infectious protein-based vaccine candidates. Specifically, soluble envelope protein (sE), and virus-like particles (VLPs), comprised of the precursor of membrane and envelope proteins, were generated, characterized, and studied for their immunogenicity in mice. Results showed that the VLPs induced more potent virus neutralizing response compared to sE, even though the total anti-envelope IgG content induced by the two antigens was similar. Depletion of anti-monomeric E protein antibodies from mouse immune sera suggested that the neutralizing antibodies elicited by the VLPs targeted epitopes spanning the highly organized structure of multimer of the E protein, whereas the antibody response induced by sE focused on E monomers. Thus, our results indicate that VLPs represent a promising LIV vaccine candidate.