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PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12642
Author(s):  
Berta Blanch-Lázaro ◽  
Raoul F.H. Ribot ◽  
Mathew L. Berg ◽  
Soren Alexandersen ◽  
Andrew T.D. Bennett

Background Beak and feather disease virus (BFDV) is a circovirus that infects captive and wild psittacine birds, and is of conservation concern. The haemagglutination inhibition (HI) assay is used to determine antibody titres against BFDV, and the use of dried blood spots (DBS) on filter paper stored at room temperature has been suggested to be an equally valid technique to the use of frozen serum. However, research on other pathogens has found variable results when investigating the longevity of antibodies stored on DBS at room temperature. Consequently, we aimed to test the temporal stability of antibodies to BFDV in DBS samples stored long-term at room temperature. A further goal was to add to the current knowledge of antibody response to naturally acquired BFDV infection in crimson rosellas (Platycercus elegans). Methods Blood was collected from wild P. elegans in Victoria, Australia, that had been live-trapped (n = 9) or necropsied (n = 11). BFDV virus load data were obtained from blood stored in ethanol by real-time quantitative PCR (qPCR); antibody titres were obtained by HI assay from either DBS or serum samples, which had been collected concurrently. All HI assays were performed commercially by the Veterinary Diagnostic Laboratory (VDL) in Charles Sturt University, Australia, who were blind to BFDV blood status. Results HI titres from DBS stored at room temperature declined significantly over time (~80 weeks). By contrast, frozen serum samples assayed after 80 weeks in storage all had high HI titres, only varying up to one dilution step from the initial HI titres obtained from DBS at 3–6 weeks after sampling. Weak HI titres from DBS samples all came back negative when the test was repeated only nine weeks later. Novel high HI titres were reported in P. elegans, and while most birds with high antibody titres had corresponding negative qPCR results, a single subadult presented with high HI titres and virus load simultaneously. Conclusion Detection of antibodies on filter paper stored at room temperature decreases over time, increasing the chances of false negatives in these samples, and in repeated testing of samples with weak HI titres. Consequently, serum should be the preferred sample type to use for seroepidemiological studies on BFDV in parrots and other bird species. When not possible, it may help to store DBS on filter paper at −20 °C or lower. However, prompt testing of DBS samples (e.g., <6 weeks in storage) is recommended pending further research on antibody temporal stability. We also show that P. elegans, especially adults, can produce high antibody titres against BFDV, which may help them resist infection.


2021 ◽  
Author(s):  
Dalin Li ◽  
Alexander Xu ◽  
Emebet Mengesha ◽  
Rebecca Elyanow ◽  
Rachel M. Gittelman ◽  
...  

AbstractBackgroundVaccination against SARS-CoV-2 is a highly effective strategy to protect against infection, which is predominantly mediated by vaccine-induced antibodies. Postvaccination antibodies are robustly produced by those with inflammatory bowel disease (IBD) even on immune-modifying therapies but are blunted by anti-TNF therapy. In contrast, T-cell response which primarily determines long-term efficacy against disease progression,, is less well understood. We aimed to assess the post-vaccination T-cell response and its relationship to antibody responses in patients with inflammatory bowel disease (IBD) on immune-modifying therapies.MethodsWe evaluated IBD patients who completed SARS-CoV-2 vaccination using samples collected at four time points (dose 1, dose 2, 2 weeks after dose 2, 8 weeks after dose 2). T-cell clonal analysis was performed by T-cell Receptor (TCR) immunosequencing. The breadth (number of unique sequences to a given protein) and depth (relative abundance of all the unique sequences to a given protein) of the T-cell clonal response were quantified using reference datasets and were compared to antibody responses.ResultsOverall, 303 subjects were included (55% female; 5% with prior COVID) (Table). 53% received BNT262b (Pfizer), 42% mRNA-1273 (Moderna) and 5% Ad26CoV2 (J&J). The Spike-specific clonal response peaked 2 weeks after completion of the vaccine regimen (3- and 5-fold for breadth and depth, respectively); no changes were seen for non-Spike clones, suggesting vaccine specificity. Reduced T-cell clonal depth was associated with chronologic age, male sex, and immunomodulator treatment. It was preserved by non-anti-TNF biologic therapies, and augmented clonal depth was associated with anti-TNF treatment. TCR depth and breadth were associated with vaccine type; after adjusting for age and gender, Ad26CoV2 (J&J) exhibited weaker metrics than mRNA-1273 (Moderna) (p=0.01 for each) or BNT262b (Pfizer) (p=0.056 for depth). Antibody and T-cell responses were only modestly correlated. While those with robust humoral responses also had robust TCR clonal expansion, a substantial fraction of patients with high antibody levels had only a minimal T-cell clonal response.ConclusionAge, sex and select immunotherapies are associated with the T-cell clonal response to SARS-CoV-2 vaccines, and T-cell responses are low in many patients despite high antibody levels. These factors, as well as differences seen by vaccine type may help guide reimmunization vaccine strategy in immune-impaired populations. Further study of the effects of anti-TNF therapy on vaccine responses are warranted.


Author(s):  
V. S. Vakin ◽  
I. V. Amosova ◽  
E. M. Vojcekhovskaya ◽  
T. A. Timoshicheva ◽  
A. A. Vasileva ◽  
...  

Currently, the assessment of the immunogenic properties of influenza viruses as a part of influenza vaccines, is carried out by using seroprotection, seroconversion as well as the rate of increases in post-vaccination antibodies. At the same time, significant differences in the immunogenicity of vaccines related to dynamic formation of high antibody titers responsible for long-term protection of the vaccinated, are neglected.Influenza viruses such as A (H1N1) pdm09 that caused 2009-2010 pandemic continue to circulate in the population, therefore, the assessment of the immunogenic activity of vaccine viruses prepared during the pandemic period is interesting in for the methodology to prepare pandemic vaccines to be used in various groups (adults, children, elderly people).Analyzing immunogenicity of influenza vaccines used during the 2009-10 swine influenza pandemic and the post-pandemic period up to the year 2014 was carried out by applying the graphical method for assessing immunogenicity (immunographs) measured as follows: for each group of vaccinated subjects (depending on the vaccine used), an increased rate in antibody level was calculated and the graphs of immunogenicity were plotted. An increased rate of serum antibodies magnitude from vaccinated subjects and the number of sera (in%) with a given fold increase rate in antibody level from 1 to the maximum magnitude were plotted on the x- and y-axis, respectively. The proposed method for assessing immunogenicity allows to plot immunogenicity graphs regardless of the serum antibodies level found in volunteers. The assessment described above revealed a several features for developing immune response to the pandemic virus A (H1N1)pdm09 such as the lack of immune response in a substantial number of adult volunteers (25-27%%) and young children (60-70%%) after monovaccine administration. The reason for such immune response can be both an insufficient dose of vaccine-containing viral antigen and suppressed immune response caused by the influenza A(H1N1)pdm09.A study on the immunogenic properties for seasonal influenza vaccines containing the influenza A (H1N1) pdm09 virus antigen in the years 2010 - 2014 revealed a variety in emerging humoral immunity ranging from a short-term, low-frequency increase in antibodies from vaccinated children to the formation of high antibody titers in elderly.Practically, immunographic analysis of influenza vaccines particularly those derived from the influenza A (H1N1)pdm09 virus, may result in proposing recommendations to increase an antigenic load at the beginning of a pandemic cycle and/or block the suppressive properties of vaccine-contained viruses in pediatric vaccines, because escalating virus dose in the vaccine may not always be achievable in this case.


2021 ◽  
Vol 12 ◽  
Author(s):  
Johnstone Tcheou ◽  
Ariel Raskin ◽  
Gagandeep Singh ◽  
Hisaaki Kawabata ◽  
Dominika Bielak ◽  
...  

Despite global vaccination efforts, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to evolve and spread globally. Relatively high vaccination rates have been achieved in most regions of the United States and several countries worldwide. However, access to vaccines in low- and mid-income countries (LMICs) is still suboptimal. Second generation vaccines that are universally affordable and induce systemic and mucosal immunity are needed. Here we performed an extended safety and immunogenicity analysis of a second-generation SARS-CoV-2 vaccine consisting of a live Newcastle disease virus vector expressing a pre-fusion stabilized version of the spike protein (NDV-HXP-S) administered intranasally (IN), intramuscularly (IM), or IN followed by IM in Sprague Dawley rats. Local reactogenicity, systemic toxicity, and post-mortem histopathology were assessed after the vaccine administration, with no indication of severe local or systemic reactions. Immunogenicity studies showed that the three vaccination regimens tested elicited high antibody titers against the wild type SARS-CoV-2 spike protein and the NDV vector. Moreover, high antibody titers were induced against the spike of B.1.1.7 (alpha), B.1.351 (beta) and B.1.617.2 (delta) variants of concern (VOCs). Importantly, robust levels of serum antibodies with neutralizing activity against the authentic SARS-CoV-2 USA‐WA1/2020 isolate were detected after the boost. Overall, our study expands the pre-clinical safety and immunogenicity characterization of NDV-HXP-S and reinforces previous findings in other animal models about its high immunogenicity. Clinical testing of this vaccination approach is ongoing in different countries including Thailand, Vietnam, Brazil and Mexico.


2021 ◽  
Author(s):  
Vivek Naranbhai ◽  
Kerri J St. Denis ◽  
Evan C Lam ◽  
Onosereme Ofoman ◽  
Wilfredo F Garcia-Beltran ◽  
...  

Patients with cancer are more likely to have impaired immune responses to SARS CoV-2 vaccines. We studied the breadth of responses against SARS CoV-2 variants followingly primary vaccination in 178 patients with a variety of tumor types, and after booster doses in a subset. Neutralization of alpha, beta, gamma and delta SARS-CoV-2 variants was impaired relative to wildtype (Wuhan), regardless of vaccine type. Regardless of viral variant, mRNA1273 was the most immunogenic, followed by BNT162b2 and then Ad26.COV2.S. Neutralization of more variants (breadth) was associated with higher magnitude of wildtype neutralization, and increase with time since vaccination; increased age associated with lower breadth. Anti-spike binding antibody concentrations were a good surrogate for breadth (PPV=90% at >1000U/ml). Booster SARS-CoV-2 vaccines conferred enhanced breadth. These data suggest that achieving a high antibody titer is desirable to achieve broad neutralization; a single booster dose with current vaccines increases breadth of responses against variants.


Vaccine ◽  
2021 ◽  
Author(s):  
Harika Oyku Dinc ◽  
Nese Saltoglu ◽  
Gunay Can ◽  
Ilker Inanc Balkan ◽  
Beyhan Budak ◽  
...  

2021 ◽  
Author(s):  
Brandon K. Wilder ◽  
Vladimir Vigdorovich ◽  
Sara Carbonetti ◽  
Nana Minkah ◽  
Nina Hertoghs ◽  
...  

Vaccine-induced sterilizing protection from infection with the Plasmodium parasite, the pathogen that causes malaria, will be an essential tool in the fight against malaria as it would prevent both malaria-related disease and transmission. Stopping the relatively small number of parasites injected by the mosquito before they can migrate from the skin to the liver is an attractive goal. Antibody-eliciting vaccines have been used to pursue this objective by targeting the major parasite surface protein present during this stage, the circumsporozoite protein (CSP). While CSP-based vaccines have recently had encouraging success in disease reduction, this was only achieved with extremely high antibody titers and appeared less effective for a complete block of infection. While such disease reduction is important, these results also indicate that further improvements to vaccines based solely on CSP will likely yield diminishing benefits towards the goal of durable, infection-blocking immunity. Here, we show that monoclonal antibodies (mAbs) recognizing the sporozoite protein TRAP/SSP2 across the major protein domains exhibit a range of inhibitory capacity and that these mAbs can augment CSP-based protection despite delivering no sterile protection on their own. Therefore, pursuing a multivalent subunit vaccine immunization is a promising strategy for improving infection-blocking malaria vaccines.


2021 ◽  
Vol 9 ◽  
Author(s):  
Andrea Trevisan ◽  
Paola Mason ◽  
Annamaria Nicolli ◽  
Stefano Maso ◽  
Chiara Bertoncello

Objective: Rubella is a very diffusive but relatively benign infectious disease unless contracted during pregnancy, when it causes congenital rubella syndrome. The aim of this research was to determine the prevalence and titer of antirubella antibodies in a population of future healthcare workers (students at the school of medicine).Methods: The cohort consisted of 11,022 students who underwent antibody analysis after the presentation of a vaccine certificate.Results: Vaccination compliance was very high, particularly in younger students (born after 1995), reaching almost 100% (at least one dose). Unvaccinated students born before 1990 had high seropositivity (&gt;95%), but this percentage dropped to zero among the youngest students. Variables affecting antibody titer included year of birth and sex. Considering only vaccinated students, a greater antibody response was observed if the vaccine was administered between 8 and 10 years of age. Female sex was associated with more significant (p &lt; 0.0001) positivity and higher antibody titer after one and two doses. However, this difference appeared less consistent in relation to year of birth.Conclusions: The studied population exhibited excellent vaccination compliance, high seropositivity, and high antibody titer. Vaccine and immune coverage were higher than what is deemed necessary to achieve herd immunity.


Author(s):  
Megan E. Trostle ◽  
Maria E. Aguero-Rosenfeld ◽  
Ashley S. Roman ◽  
Jennifer L. Lighter

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