Early B cell transcriptomic markers of measles-specific humoral immunity following a 3rd dose of MMR vaccine.

B cell transcriptomic signatures hold promise for the early prediction of vaccine-induced humoral immunity and vaccine protective efficacy. We performed a longitudinal study in 232 healthy adult participants before/after a 3rd dose of MMR (MMR3) vaccine. We assessed baseline and early transcriptional patterns in purified B cells and their association with measles-specific humoral immunity after MMR vaccination using two analytical methods ("per gene" linear models and joint analysis). Our study identified distinct early transcriptional signatures/genes following MMR3 that were associated with measles-specific neutralizing antibody titer and/or binding antibody titer. The most significant genes included: the interleukin 20 receptor subunit beta/IL20RB gene (a subunit receptor for IL-24, a cytokine involved in the germinal center B cell maturation/response); the phorbol-12-myristate-13-acetate-induced protein 1/PMAIP1, the brain expressed X-linked 2/BEX2 gene and the B cell Fas apoptotic inhibitory molecule/FAIM, involved in the selection of high-affinity B cell clones and apoptosis/regulation of apoptosis; as well as IL16 (encoding the B lymphocyte-derived IL-16 ligand of CD4), involved in the crosstalk between B cells, dendritic cells and helper T cells. Significantly enriched pathways included B cell signaling, apoptosis/regulation of apoptosis, metabolic pathways, cell cycle-related pathways, and pathways associated with viral infections, among others. In conclusion, our study identified genes/pathways linked to antigen-induced B cell proliferation, differentiation, apoptosis, and clonal selection, that are associated with, and impact measles virus-specific humoral immunity after MMR vaccination.

Detection of SARS-CoV-2-Specific Cells Utilizing Whole Proteins and/or Peptides in Human PBMCs Using IFN-Æ´ ELISPOT Assay.

SARS-CoV-2 continues to threaten global public health, making COVID-19 immunity studies of utmost importance. Waning of antibody responses postinfection and/or vaccination and the emergence of immune escape variants have been ongoing challenges in mitigating SARS-CoV-2 morbidity and mortality. While a tremendous amount of work has been done to characterize humoral immune responses to SARS-CoV-2 virus and vaccines, cellular immunity, mediated by T cells, is critical for efficient viral control and protection and demonstrates high durability and cross-reactivity to coronavirus variants. Thus, ELISPOT, a standard assay for antigen-specific cellular immune response assessment, allows us to evaluate SARS-CoV-2-specific T-cell response by quantifying the frequency of SARS-CoV-2-specific cytokine-secreting cells in vitro. We have outlined a detailed procedure to study T-cell recall responses to SARS-CoV-2 in human peripheral blood mononuclear cells (PBMCs) following infection and/or vaccination using an optimized IFN-γ ELISPOT assay. Our methodologies can be adapted to assess other cytokines and are a useful tool for studying other viral pathogen and/or peptide-specific T-cell responses.

A multifaceted approach for identification, validation, and immunogenicity of naturally processed and in silico-predicted highly conserved SARS-CoV-2 peptides.

SARS-CoV-2 remains a major global public health concern. Antibody waning and immune escape variant emergence necessitate the development of next generation vaccines that induce cross-reactive durable immune responses. T cell responses to SARS-CoV-2 demonstrate higher conservation, antigenic breadth, and longevity than antibody responses. Therefore, we sought to identify pathogen-derived T cell epitopes for a potential peptide-based vaccine. We pursued an approach leveraging: 1) liquid chromatography and tandem mass spectrometry (LC-MS/MS)-based identification of peptides from ancestral SARS-CoV-2-infected cell lines, 2) epitope prediction algorithms, and 3) overlapping peptide libraries. From this strategy, we identified 380 unique SARS-CoV-2-derived peptide sequences, including 53 antigenic HLA class I and class II peptides from multiple structural and non-structural/accessory viral proteins. These peptide sequences were highly conserved across variants of concern/interest (VoC/VoIs), and are estimated to achieve coverage of >96% of the world population. Our findings validate this discovery pipeline for peptide identification and immunogenicity testing, and are a crucial step toward the development of a next-generation multi-epitope SARS-CoV-2 peptide vaccine, and a novel vaccine platform methodology.

Functional humoral and cellular response of monovalent COVID-19-vaccines against Omicron BA.2 variant of SARS-CoV-2 in patients with chronic lymphocytic leukemia.

We designed a prospective study to evaluate the humoral (using a surrogate virus neutralization test) and cellular (using an IFN-γ ELISpot) immune response among patients with chronic lymphocytic leukemia (CLL) against Wuhan-Hu-1 and Omicron BA.2 strains of SARS-CoV-2, after mRNA-based vaccination. The proportion of patients with a functional humoral response was higher among untreated CLL patients compared to treated CLL patients against both Wuhan-Hu-1 and Omicron BA.2 after the second and the third dose of vaccination, and at 12 months after the first dose. The proportion of positive cellular response against the peptide pool covering the full-length Wuhan-Hu-1 spike protein was similar between untreated and treated CLL patients at all three timepoints. The cellular response to the mutated regions of BA.2 spike protein was lower than the response to the corresponding regions in the ancestral spike after the second dose, but this difference was eliminated after the third dose.

The Influence of Sex, Body Mass Index, and Age on Cellular and Humoral Immune Responses Against Measles After a Third Dose of Measles-Mumps-Rubella Vaccine.

BACKGROUND: A third dose of measles-mumps-rubella vaccine (MMR3) is recommended in mumps outbreak scenarios, but the immune response and the need for widespread use of MMR3 remain uncertain. Herein, we characterized measles-specific immune responses to MMR3 in a cohort of 232 healthy subjects. METHODS: Serum and peripheral blood mononuclear cells (PBMCs) were sampled at day 0 and day 28 after MMR3. Measles-specific binding and neutralizing antibodies were quantified in sera by enzyme-linked immunosorbent assay and a microneutralization assay, respectively. PBMCs were stimulated with inactivated measles virus, and the release of cytokines/chemokines was assessed by a multiplex assay. Demographic variables of subjects were examined for potential correlations with immune outcomes. RESULTS: Of the study participants, 95.69% and 100% were seropositive at day 0 and day 28, respectively. Antibody avidity significantly increased from 38.08% at day 0 to 42.8% at day 28 (P = .00026). Neutralizing antibodies were significantly enhanced, from 928.7 at day 0 to 1289.64 mIU/mL at day 28 (P = .0001). Meanwhile, cytokine/chemokine responses remained largely unchanged. Body mass index was significantly correlated with the levels of inflammatory cytokines/chemokines. CONCLUSIONS: Measles-specific humoral immune responses, but not cellular responses, were enhanced after MMR3 receipt, extending current understanding of immune responses to MMR3 and supporting MMR3 administration to seronegative or high-risk individuals.

Distorted Human Decision-Making as a Critical Aspect of Pandemic Planning and Preparedness.

The United States continues to experience lower than expected vaccination rates against COVID-19 due to a variety of barriers such as lack of trust, lack of planning, cultural perspectives and issues, suboptimal communication, and political/economic conflicts of interest. In this paper issues of human behavior and decision-making are highlighted as integral to understanding the generally poor US response to the SARS-CoV-2 pandemic. In particular, the US pandemic response was significantly distorted through a combination of cultural and human behavior issues related to conflicting leadership, cultural individualism, the prevalent idea of the democratization of expertise, and a false epistemological lens for decision-making. Including experts from multiple disciplines reveals how to address the human behavioral side of pandemic planning and operations to increase vaccine coverage rates. Including content experts from psychology and the social sciences allows the explicit recognition and preparation for distorted human behavior in planning for future pandemic response.

Vaccine hesitancy and health care providers: Using the preferred cognitive styles and decision- making model and empathy tool to make progress.

Low vaccination rates among health care providers (HCPs) pose a risk to themselves, their colleagues, their patients, and the general public. This paper seeks to frame the issues surrounding health care provider vaccine hesitancy and vaccination rates, as well as explore factors influencing respective decision-making, including health care occupation and demographic characteristics. This paper will then propose the use of the Preferred Cognitive Style and Decision-Making (PCSDM) Model and the Empathy Tool to increase health care provider vaccination rates, and will end by discussing several recommendations. It is important while discussing HCP vaccination rates to not view them as a monolithic group or apply "one-size-fits-all" approaches, and thus it is essential to present information and engage in conversations in ways that align with how the HCP takes in and processes information and decisions. Furthermore, it is vital to increase health literacy across the spectrum of HCP programs and professions. To this end, it is important to teach and incorporate the PCSDM Model and Empathy Tool, along with information about how individuals think and make decisions, into vaccine education programs and training sessions.