Report of a SPEAC webinar 22 september 2023: Sensorineural hearing loss, lassa virus disease and vaccines.

Lassa virus (LASV) belongs to the Arenavirus family. LASV is endemic in several West Africa countries and causes viral hemorrhagic fevers. The Nigeria CDC has reported that an outbreak in 2024 in 28 states has resulted in 7767 suspected cases of Lassa fever, 971 confirmed cases and 166 confirmed deaths up to 11 August.

C-type lectin receptor agonists elicit functional IL21-expressing Tfh cells and induce primary B cell responses in neonates.

Introduction: C-type lectin receptor (CLR) agonists emerged as superior inducers of primary B cell responses in early life compared with Toll-like receptor (TLR) agonists, while both types of adjuvants are potent in adults.

Methods: Here, we explored the mechanisms accounting for the differences in neonatal adjuvanticity between a CLR-based (CAF01) and a TLR4-based (GLA-SE) adjuvant administered with influenza hemagglutinin (HA) in neonatal mice, by using transcriptomics and systems biology analyses.

Results: On day 7 after immunization, HA/CAF01 increased IL6 and IL21 levels in the draining lymph nodes, while HA/GLA-SE increased IL10.

Double-Blind, Placebo-Controlled, Dose-Escalating Study Evaluating the Safety and Immunogenicity of an Epitope-Specific Chemically Defined Nanoparticle RSV Vaccine.

Background: V-306 is a virus-like particle-based vaccine candidate displaying respiratory syncytial virus (RSV) F site II protein mimetics (FsIIm) as an antigenic epitope.

Methods: This was a randomized, placebo-controlled, double-blind, dose-escalating, first-in-human study, conducted in 60 women aged 18-45 years. Twenty subjects per cohort (15 vaccine and five placebo) received two V-306 intramuscular administrations on Days 0 and 56 at 15 µg, 50 µg, or 150 µg.

Advanced vaccinology training globally: Update and impact of the COVID-19 crisis.

The rapid development of innovations and new technologies, the focus on the life-course approach to immunization and equity, and the prevalent hesitancy towards vaccines requires immunization staff to be well-trained and updated regularly in order to deliver quality immunization services to the public. The need for advanced vaccinology training is therefore paramount. In preparation for a second Global Workshop on Advanced Vaccinology Training that took place in March 2022, this paper presents the results of a survey aiming to provide a thorough update of a landscape analysis on advanced vaccinology courses conducted in 2018 and a look at the impact of the COVID-19 crisis.

Fitness of B-Cell Responses to SARS-CoV-2 WT and Variants Up to One Year After Mild COVID-19 - A Comprehensive Analysis.

Objective: To comprehensively evaluate SARS-CoV-2 specific B-cell and antibody responses up to one year after mild COVID-19.

Methods: In 31 mildly symptomatic COVID-19 participants SARS-CoV-2-specific plasmablasts and antigen-specific memory B cells were measured by ELISpot. Binding antibodies directed against the proteins spike (S), domain S1, and nucleocapsid (N) were estimated using rIFA, ELISA, and commercially available assays, and avidity measured using thiocyanate washout.

Replication-Deficient Lymphocytic Choriomeningitis Virus-Vectored Vaccine Candidate for the Induction of T Cell Immunity against .

() represents a major burden to global health, and refined vaccines are needed. Replication-deficient lymphocytic choriomeningitis virus (rLCMV)-based vaccine vectors against cytomegalovirus have proven safe for human use and elicited robust T cell responses in a large proportion of vaccine recipients. Here, we developed an rLCMV vaccine expressing the antigens TB10.

Epicutaneous immunization using synthetic virus-like particles efficiently boosts protective immunity to respiratory syncytial virus.

Despite the substantial health and economic burden caused by RSV-associated illness, no vaccine is available. The sole licensed treatment (palivizumab), composed of a monoclonal neutralizing antibody, blocks the fusion of the virus to the host cell but does not prevent infection. The development of a safe and efficacious RSV vaccine is therefore a priority, but also a considerable challenge, and new innovative strategies are warranted.

Novel vaccine safety issues and areas that would benefit from further research.

Vaccine licensure requires a very high safety standard and vaccines routinely used are very safe. Vaccine safety monitoring prelicensure and postlicensure enables continual assessment to ensure the benefits outweigh the risks and, when safety problems arise, they are quickly identified, characterised and further problems prevented when possible. We review five vaccine safety case studies: (1) dengue vaccine and enhanced dengue disease, (2) pandemic influenza vaccine and narcolepsy, (3) rotavirus vaccine and intussusception, (4) human papillomavirus vaccine and postural orthostatic tachycardia syndrome and complex regional pain syndrome, and (5) RTS,S/adjuvant system 01 malaria vaccine and meningitis, cerebral malaria, female mortality and rebound severe malaria.

Vaccine-associated enhanced disease: Case definition and guidelines for data collection, analysis, and presentation of immunization safety data.

This is a Brighton Collaboration Case Definition of the term "Vaccine Associated Enhanced Disease" to be utilized in the evaluation of adverse events following immunization. The Case Definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of vaccines for SARS-CoV-2 vaccines and other emerging pathogens. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and defined levels of certainty, after an exhaustive review of the literature and expert consultation.

A TLR7/8 Agonist-Including DOEPC-Based Cationic Liposome Formulation Mediates Its Adjuvanticity Through the Sustained Recruitment of Highly Activated Monocytes in a Type I IFN-Independent but NF-κB-Dependent Manner.

Novel adjuvants, such as Toll-like receptors (TLRs) agonists, are needed for the development of new formulations able to circumvent limitations of current vaccines. Among TLRs, TLR7/8 agonists represent promising candidates, as they are well described to enhance antigen-specific antibody responses and skew immunity toward T helper (T) 1 responses. We find here that the incorporation of the synthetic TLR7/8 ligand 3M-052 in a cationic DOEPC-based liposome formulation shifts immunity toward T1 responses and elicits strong and long-lasting germinal center and follicular T helper cell responses in adult mice.

Erratum: Author Correction: Rapid dose-dependent Natural Killer (NK) cell modulation and cytokine responses following human rVSV-ZEBOV Ebolavirus vaccination.

[This corrects the article DOI: 10.1038/s41541-020-0179-4.].

Consensus summary report for CEPI/BC March 12-13, 2020 meeting: Assessment of risk of disease enhancement with COVID-19 vaccines.

A novel coronavirus (CoV), Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in late 2019 in Wuhan, China and has since spread as a global pandemic. Safe and effective vaccines are thus urgently needed to reduce the significant morbidity and mortality of Coronavirus Disease 2019 (COVID-19) disease and ease the major economic impact. There has been an unprecedented rapid response by vaccine developers with now over one hundred vaccine candidates in development and at least six having reached clinical trials.

Advanced vaccinology education: Landscaping its growth and global footprint.

In preparation for the first Global Vaccinology Training workshop in 2018, a survey of 27 advanced vaccinology courses was conducted to provide a landscape of the vaccinology education around the world. Advanced vaccinology courses have expanded dramatically over the last 20 years, with courses located in almost all regions, but with underrepresentation amongst the Eastern part of the European region, the Eastern Mediterranean and the Western Pacific regions. Most courses are of short duration (<2 weeks), have a global or regional reach, and attract a diverse range of participants from high, middle and low-income countries with representation from public health, academia, industry and less often regulators.

Rapid dose-dependent Natural Killer (NK) cell modulation and cytokine responses following human rVSV-ZEBOV Ebolavirus vaccination.

The rVSV-ZEBOV Ebolavirus vaccine confers protection within days after immunization, suggesting the contribution of innate immune responses. We report modulation of rVSV-ZEBOV vaccinee blood CD56 NK cell numbers, NKG2D or NKp30 surface receptor expression, Killer Immunoglobulin-like Receptor (KIR) cell percentages and NK-cell-related genes on day 1 post immunization. Inverse correlations existed between the concentration of several plasma cytokines and inhibitory KIR CD56 or cytokine-responsive CD56 NK cells.

The science of vaccine safety: Summary of meeting at Wellcome Trust.

Vaccines are everywhere hugely successful but are also under attack. The reason for the latter is the perception by some people that vaccines are unsafe. However that may be, vaccine safety, life any other scientific subject, must be constantly studied.

Corrigendum: Site-Specific DC Surface Signatures Influence CD4 T Cell Co-stimulation and Lung-Homing.

[This corrects the article DOI: 10.3389/fimmu.2019.

Neonatal T Follicular Helper Cells Are Lodged in a Pre-T Follicular Helper Stage Favoring Innate Over Adaptive Germinal Center Responses.

T follicular helper (T) cells have emerged as a critical limiting factor for controlling the magnitude of neonatal germinal center (GC) reactions and primary vaccine antibody responses. We compared the functional attributes of neonatal and adult T cells at the transcriptomic level and demonstrated that the T cell program is well-initiated in neonates although the T gene-expression pattern (i.e.

Maternal Antibodies Inhibit Neonatal and Infant Responses to Vaccination by Shaping the Early-Life B Cell Repertoire within Germinal Centers.

Maternal antibodies (MatAbs) protect offspring from infections but limit their responses to vaccination. The mechanisms of this inhibition are still debated. Using murine early-life immunization models mimicking the condition prevailing in humans, we observed the induction of CD4-T, T follicular helper, and germinal center (GC) B cell responses even when early-life antibody responses were abrogated by MatAbs.

Site-Specific DC Surface Signatures Influence CD4 T Cell Co-stimulation and Lung-Homing.

Dendritic cells (DCs) that drain the gut and skin are known to favor the establishment of T cell populations that home to the original site of DC-antigen (Ag) encounter by providing "imprinting" signals to T cells in the lymph node (LN). To study the induction of lung T cell-trafficking, we used a protein-adjuvant murine intranasal and intramuscular immunization model to compare -activated Ag DCs in the lung and muscle-draining LNs. Higher frequencies of Ag CD11b DCs were observed in lung-draining mediastinal LNs (MedLN) compared to muscle-draining inguinal LNs (ILN).

Reactivating Immunity Primed by Acellular Pertussis Vaccines in the Absence of Circulating Antibodies: Enhanced Bacterial Control by TLR9 Rather Than TLR4 Agonist-Including Formulation.

Pertussis is still observed in many countries despite of high vaccine coverage. Acellular pertussis (aP) vaccination is widely implemented in many countries as primary series in infants and as boosters in school-entry/adolescents/adults (including pregnant women in some). One novel strategy to improve the reactivation of aP-vaccine primed immunity could be to include genetically- detoxified pertussis toxin and novel adjuvants in aP vaccine boosters.

Narcolepsy and Pandemic Influenza Vaccination: What We Need to Know to be Ready for the Next Pandemic.

After the initial identification of the H1N1 pandemic influenza strain in Mexico in April 2009 and its subsequent global spread, several monovalent influenza vaccines were developed as part of the pandemic response. Three of these vaccines, Pandemrix, Arepanrix and Focetria were adjuvanted. One of these, the AS03-adjuvanted Pandemrix vaccine, was primarily used in Europe.

Global vaccinology training: Report from an ADVAC workshop.

At a workshop on 7-8 November 2018 the leaders of 26 advanced vaccinology courses met to carry out an extensive review of the existing courses worldwide, in order to identify education gaps and future needs and discuss potential collaboration. The main conclusions of the workshop concerned: opportunities for strengthening and expanding the global coverage of vaccinology training; evaluation of vaccinology courses; updating knowledge after the course; how to facilitate post-course 'cascade' training; developing and sharing best practices; the application of online and innovative approaches in adult education; and how to reduce costs and facilitate wider access to vaccinology training. The importance of collaboration and information exchange through networks of alumni and between courses was stressed.

Epidermal micro-perforation potentiates the efficacy of epicutaneous vaccination.

The skin is an immune organ comprised of a large network of antigen-presenting cells such as dendritic cells, making it an attractive target for the development of new vaccines and immunotherapies. Recently, we developed a new innovative and non-invasive vaccination method without adjuvant based on epicutaneous vaccine patches on which antigen forms a dry deposit. Here we describe in mice a method for potentiating the efficacy of our epicutaneous vaccination approach using a minimally invasive and epidermis-limited skin preparation based on laser-induced micro-perforation.