scholarly journals The Chimeric Binjari-Zika Vaccine Provides Long-Term Protection against ZIKA Virus Challenge

Vaccines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 85
Author(s):  
Jessamine E. Hazlewood ◽  
Bing Tang ◽  
Kexin Yan ◽  
Daniel J. Rawle ◽  
Jessica J. Harrison ◽  
...  
Keyword(s):  
Protective Immunity ◽  
Body Weight Loss ◽  
Vaccine Recipient ◽  
Neutralizing Antibody ◽  
The Novel ◽  
Post Vaccination ◽  
Virus Challenge ◽  
Single Vaccination ◽  
Flavivirus Vaccine

We recently developed a chimeric flavivirus vaccine technology based on the novel insect-specific Binjari virus (BinJV) and used this to generate a chimeric ZIKV vaccine (BinJ/ZIKA-prME) that protected IFNAR-/- dams and fetuses from infection. Herein, we show that a single vaccination of IFNAR-/- mice with unadjuvanted BinJ/ZIKA-prME generated neutralizing antibody responses that were retained for 14 months. At 15 months post vaccination, mice were also completely protected against detectable viremia and substantial body weight loss after challenge with ZIKVPRVABC59. BinJ/ZIKA-prME vaccination thus provided long-term protective immunity without the need for adjuvant or replication of the vaccine in the vaccine recipient, both attractive features for a ZIKV vaccine.

scholarly journals Protective Immunity against Vibrio harveyi in Grouper Induced by Single Vaccination with Poly (Lactide-co-glycolide) Microparticles Releasing Pleurocidin Peptide and Recombinant Glyceraldehyde-3-phosphate Dehydrogenase

Vaccines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 33
Author(s):  
Shang-Pin Liu ◽  
Shu-Chun Chuang ◽  
Chung-Da Yang
Keyword(s):  
Single Dose ◽  
Immune Responses ◽  
Protective Immunity ◽  
Vibrio Harveyi ◽  
Attractive Feature ◽  
Tnf Α ◽  
Single Vaccination ◽  
Highly Virulent ◽  
Dose Vaccine

The peptide adjuvant, pleurocidin (PLE), and the Vibrio harveyi antigen, recombinant glyceraldehyde-3-phosphate dehydrogenase (rGAPDH) protein, were encapsulated with poly (lactide-co-glycolide) (PLG) polymers in our previous study to produce PLG-encapsulated PLE plus rGAPDH microparticles (PLG-PLE/rGAPDH MPs) that sustained stable release of both PLE and rGAPDH as well as, after two-time vaccination with MPs, generated long-term protective immunity against V. harveyi in grouper. Stable controlled-release of PLE plus rGAPDH from PLG-PLE/rGAPDH MPs is an attractive feature for developing an effective single-dose vaccine. In the present study, therefore, we aim to evaluate whether single administration with PLG-PLE/rGAPDH MPs in grouper would result in protective immunity against V. harveyi. Peritoneal vaccination of grouper with one dose of PLG-PLE/rGAPDH MPs raised serum titers over a long 12-week period. Moreover, twelve weeks after vaccination, significant lymphocyte proliferation and maximum TNF-α production were found in grouper immunized with a single dose of PLG-PLE/rGAPDH MPs. More importantly, immune responses elicited by single vaccination with PLG-PLE/rGAPDH MPs protected 80% of fish against a lethal peritoneal challenge of the highly virulent V. harveyi (Vh MML-1). In conclusion, our data truly reveal the feasibility of the development of a single-dose vaccine against V. harveyi based on PLG-PLE/rGAPDH MPs.

scholarly journals Single-shot rAAV5-based Vaccine Provides Long-term Protective Immunity against SARS-CoV-2 and Its Variants

2021 ◽  
Author(s):  
Guochao Liao ◽  
Xingxing Fan ◽  
Hungyan Lau ◽  
Zhongqiu Liu ◽  
Chinyu Li ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Neutralizing Antibodies ◽  
Protective Immunity ◽  
Challenge Test ◽  
Single Shot ◽  
Strong Immune Response ◽  
Virus Challenge ◽  
Limited Effectiveness ◽  
One Year

SummaryThe COVID-19 pandemic and the SARS-CoV-2 with its variants have posed unprecedented challenges worldwide. Existing vaccines have limited effectiveness against the SARS-CoV-2 variants. Therefore, novel vaccines to match current mutated viral lineages with long-term protective immunity are urgently in demand. In the current study, we for the first time designed a recombinant Adeno-Associated Virus 5 (rAAV5)-based vaccine named as rAAV-COVID-19 vaccine (Covacinplus) by using RBD-plus of spike protein with both the single-stranded and the self-complementary AAV5 delivering vectors (ssAAV5 and scAAAV5), which provides excellent protection from SARS-CoV-2 infection. A single dose vaccination induced the strong immune response against SARS-CoV-2. The induced neutralizing antibodies (NAs) titers were maintained at a high peak level of over 1:1024 even after more than one year of injection and accompanied with functional T-cells responses in mice. Importantly, both ssAAV- and scAAV-based RBD-plus vaccines exhibited high levels of serum NAs against current circulating variants including variants Alpha, Beta, Gamma and Delta. SARS-CoV-2 virus challenge test showed that ssAAV5-RBD-plus vaccine protected both young and old age mice from SARS-CoV-2 infection in the upper and the lower respiratory tracts. Moreover, whole genome sequencing demonstrated that AAV vector DNA sequences were not found in the genome of the vaccinated mice after one year vaccination, demonstrating excellent safety of the vaccine. Taken together, this study suggests that rAAV5-based vaccine is powerful against SARS-CoV-2 and its variants with long-term protective immunity and excellent safety, which has great potential for development into prophylactic vaccination in human to end this global pandemic.

scholarly journals A Novel High-Intensity Focused Ultrasound-Treated Herpes Simplex Virus 2 Vaccine Induces Long-Term Protective Immunity against Lethal Challenge in Mice

mSphere ◽  
2020 ◽  
Vol 5 (6) ◽  
pp. e00859-20
Author(s):  
Juhua Xiao ◽  
Xin Zhou ◽  
Ye Luo ◽  
Shuang Wang ◽  
Zhili Yang ◽  
...  
Keyword(s):  
High Intensity ◽  
Protective Immunity ◽  
Focused Ultrasound ◽  
High Intensity Focused Ultrasound ◽  
The Novel ◽  
Hifu Treatment ◽  
Lethal Challenge ◽  
Simplex Virus ◽  
Herpes Simplex Virus 2

ABSTRACTHigh-intensity focused ultrasound (HIFU), a noninvasive ablation therapy that has been widely used clinically in ablation of solid tumors, induces immune sensitization. We therefore in this study investigated whether HIFU treatment could enhance the efficacy of a herpes simplex virus 2 (HSV-2) vaccine. First, we observed that in HSV-2-positive cervical intraepithelial neoplasia (CIN) II patients, HIFU treatment induced significantly higher anti-HSV-2 neutralization response than surgical removal. Next, we tested the efficacy of HIFU-treated, UV-inactivated HSV-2-infected cells as a proof-of-concept vaccine in mice. Our data showed that HIFU-treated formulation significantly enhanced HSV-2 antibody titers and neutralization titers, compared to UV-, microwave (MW)-, or freeze-thaw (FT)-treated formulations. HIFU treatment also promoted the Th1/2 cell-mediated response. A long-term full protection was observed in mice that received the HIFU-treated formulation, and no weight loss was detected. Our findings indicate that the novel application of HIFU in vaccine production may represent a rational way to improve vaccine efficacy.IMPORTANCE High-intensity focused ultrasound (HIFU) is mainly used in tumor ablation and tumor vaccinology study. It has been shown to induce immune sensitization and enhance tumor responsiveness to other therapies. Our study has shown enhanced anti-HSV-2 response in HIFU-treated CIN II patients. Furthermore, in a murine model, we have demonstrated that HIFU-treated HSV-2 vaccine induced long-term protective immunity against lethal challenge. Our findings indicate that the novel application of HIFU in vaccine production may represent a rational way to improve vaccine efficacy.

scholarly journals Dynamics of neutralizing antibody responses to SARS-CoV-2 in patients with COVID-19: an observational study

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Xin Xu ◽  
Sheng Nie ◽  
Yanqun Wang ◽  
Quanxin Long ◽  
Hong Zhu ◽  
...  
Keyword(s):  
Protective Immunity ◽  
Neutralization Test ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Half Time ◽  
Peak Titer ◽  
Neutralization Rate ◽  
Repeat Infection ◽  
Post Onset

AbstractOur understanding of the protective immunity, particularly the long-term dynamics of neutralizing antibody (NAbs) response to SARS-CoV-2, is currently limited. We enrolled a cohort of 545 COVID-19 patients from Hubei, China, who were followed up up to 7 months, and determined the dynamics of NAbs to SARS-CoV-2 by using a surrogate virus neutralization test (sVNT). In our validation study, sVNT IC50 titers and the neutralization rate measured at a single dilution (1:20) were well correlated with FRNT titers (r = 0.85 and 0.84, respectively). The median time to seroconversion of NAbs was 5.5 days post onset of symptoms. The rate of positive sVNT was 52% in the first week, reached 100% in the third week, and remained above 97% till 6 months post onset. Quantitatively, NAbs peaked in the fourth week and only a quarter of patients had an estimated peak titer of >1000. NAbs declined with a half-time of 61 days (95% CI: 49–80 days) within the first two months, and the decay deaccelerated to a half-time of 104 days (95% CI: 86–130 days) afterward. The peak levels of NAbs were positively associated with severity of COVID-19 and age, while negatively associated with serum albumin levels. The observation that the low-moderate peak neutralizing activity and fast decay of NAbs in most naturally infected individuals called for caution in evaluating the feasibility of antibody-based therapy and vaccine durability. NAbs response positively correlated with disease severity, warning for the possibility of repeat infection in patients with mild COVID-19.

scholarly journals Reanalysis of the Pfizer mRNA BNT162b2 SARS-CoV-2 vaccine data fails to find any increased efficacy following the boost: Implications for vaccination policy and our understanding of the mode of action

2021 ◽  
Author(s):  
Allan Saul ◽  
Heidi E. Drummer ◽  
Nick Scott ◽  
Tim Spelman ◽  
Brendan S. Crabb ◽  
...  
Keyword(s):  
Protective Immunity ◽  
Neutralizing Antibody ◽  
Phase Iii ◽  
Confidence Limits ◽  
Vaccination Policy ◽  
Phase 3 ◽  
Phase Iii Trial ◽  
Short Period ◽  
Single Vaccination ◽  
Detectable Serum

AbstractBackgroundIn clinical trials two vaccinations with mRNA vaccines have shown high efficacy in preventing COVID-19. However, in the context of a pandemic, the time to generation of protective immunity, the need for and timing of a second vaccination are matters of legitimate debate. This manuscript explores the efficacy and timing of the second dose COVID-19 vaccines, including a reanalysis of data from the Pfizer mRNA BNT162b2 mRNA SARS-CoV-2 vaccine phase 3 study.Methods and findingsA non-weighted three-segment, two knot linear regression was fitted to the published cumulative infection incidence from the Pfizer BNT162b2 vaccine Phase III trial using the lspine routine in R. The optimal knot days were estimated through sensitivity analysis and the confidence limits for efficacy estimates were determined by Monte Carlo Simulations. This analysis showed the vaccine was effective from day 11 post first vaccination. The estimated efficacy over the period 11 to 28 days post first vaccination was 0.94 and there was no detectable increase in efficacy following the second vaccination. The efficacy post first vaccination substantially preceded the development of detectable serum neutralizing antibody.ConclusionsStrongly protective immunity develops rapidly following a single vaccination and at least in the short period covered by the timetable of the Phase III trial, there was no additional benefit from a second vaccination. This increases options for use of this vaccine, e.g., for ring fence vaccination, for use in travelers and for mass vaccination rollout. It highlights the need for further research into duration of immunity following a single vaccination and for understanding mechanisms of protection.

scholarly journals Neutralizing antibody titres to SARS-CoV-2 Omicron variant and wild-type virus in those with past infection or vaccinated or boosted with mRNA BNT162b2 or inactivated CoronaVac vaccines

2022 ◽  
Author(s):  
Malik Peiris ◽  
Samuel Cheng ◽  
Chris Ka Pun Mok ◽  
Yonna Leung ◽  
Susanna Ng ◽  
...  
Keyword(s):  
Protective Immunity ◽  
Neutralization Test ◽  
Neutralizing Antibody ◽  
Wild Type Virus ◽  
Wild Type ◽  
Past Infection ◽  
Post Vaccination ◽  
Antibody Titres ◽  
Duration Of Protection ◽  
Antibody Levels

Abstract Omicron, a novel SARS-CoV-2 variant has emerged and is rapidly becoming the dominant SARS-CoV-2 virus circulating globally. It is important to define reductions in virus neutralizing activity in serum of convalescent or vaccinated individuals to understand potential loss of protection from infection or re-infection. Two doses of BNT162b2 or CoronaVac vaccines provided little 50% plaque reduction neutralization test (PRNT50) antibody immunity against the Omicron variant, even at one-month post vaccination. Booster doses with BNT162b2 in those with two doses of either BNT162b2 or CoronaVac provided acceptable neutralizing immunity against Omicron variant at 1-month post-booster dose. However, three doses of BNT162b2 elicited higher levels of PRNT50 antibody to Omicron variant suggesting longer duration of protection. Convalescent from SARS-CoV-2 infection did not have protective PRNT50 antibody levels to Omicron, but a single dose of BNT162b2 vaccine provided protective immunity. Field vaccine-efficacy studies against Omicron variant against different vaccines are urgently needed.

scholarly journals Long Term Protective Immunity to Goatpox in Goats After Single Immunization with a Live Attenuated Goatpox Vaccine

2021 ◽  
Author(s):  
Bhanuprakash V ◽  
Madhusudan Hosamani ◽  
Gnanavel Venkatesan ◽  
Raj Kumar Singh
Keyword(s):  
Neutralization Assay ◽  
Single Shot ◽  
Serum Samples ◽  
Post Vaccination ◽  
Virus Challenge ◽  
Virulent Virus ◽  
Clinical Protection ◽  
Immense Potential ◽  
First Time

Abstract In this study, duration of immunity following single shot vaccination using an attenuated goatpox vaccine (GTPV/Uttarkashi/1978) was evaluated in sero-negative kids for 52 months. Long term immunity was evaluated by clinical protection upon virulent virus challenge and serum neutralization assay applied for serum samples. Rise in level of GTPV specific antibodies was found to be maximum on 21 days post vaccination, which was maintained between 1 and 2 years of immunization with steady decline. Upon virulent virus challenge on 21 days, 12, 24, 42 and 52 months post vaccination, protection in all vaccinated animals was evident, whereas, control animals developed severe clinical disease. This is for the first time that long term immunity of a live goatpox vaccine has been investigated up to 52 months of post-vaccination in goats and it has immense potential in controlling and eradicating goatpox from an enzootic situation.

scholarly journals Longitudinal determination of mRNA-vaccination induced strongly binding SARS-CoV-2 IgG antibodies in a cohort of healthcare workers with and without prior exposure to the novel coronavirus

2021 ◽  
Author(s):  
Monika Korodi ◽  
Kinga Rakosi ◽  
Zsuzsanna Jenei ◽  
Gabriella Hudak ◽  
Istvan Horvath ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Healthcare Workers ◽  
Infected Group ◽  
The Novel ◽  
Post Vaccination ◽  
Humoral Immune ◽  
Novel Coronavirus

Mass vaccination against the disease caused by the novel coronavirus (COVID-19) is a crucial step in slowing the spread of SARS-CoV-2. The BioNTech/Pfizer (BNT162b2) vaccine has been shown to induce strong immune responses among the vaccinated population. Measuring SARS-CoV-2 anti-spike protein IgG levels is a clinically convenient way to estimate post-vaccination humoral immune responses, but only limited data exists about its short- and long-term dynamics. We present a longitudinal analysis of post-vaccination IgG levels in a cohort of 122 healthcare workers vaccinated with BNT162b2 with weekly follow-up until 35 days past the first dose and results of the first monthly follow-up after that for a subset of these. This prospective, multicenter cohort study consists of two periods for short-term and long-term evaluation of post-vaccination IgG levels. Tests were carried out on 666 samples from 122 participants, using in-house anti-spike 1 and anti-nucleocapsid IgG ELISA assays and a commercial, combined version of these. Participants with previous SARS-CoV-2 infection mount a quick immune response, reaching peak IgG levels two weeks after vaccination. In contrast, the corresponding IgG levels for previously uninfected participants increase gradually, changing abruptly after the booster dose. Overall higher IgG levels are maintained for the previously infected group 35-70 days after vaccination, and we observe age-dependence of immune response as well. Our results show a robust humoral immune response mounting gradually after the first vaccine dose for the uninfected group, and a much stronger immune response within 7-14 days after the first dose for the previously infected group.

scholarly journals Robust Neutralizing Antibody Responses 6 Months Post Vaccination with BNT162b2: A Prospective Study in 308 Healthy Individuals

Life ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1077
Author(s):  
Evangelos Terpos ◽  
Vangelis Karalis ◽  
Ioannis Ntanasis-Stathopoulos ◽  
Maria Gavriatopoulou ◽  
Sentiljana Gumeni ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Healthy Individuals ◽  
Post Vaccination ◽  
The Public ◽  
Modeling Analysis ◽  
A Prospective Study ◽  
Kinetics Of ◽  
Vaccination Completion

Elucidating long-term immunity following COVID-19 vaccination is essential for decision-making regarding booster shots. The aim of this study was to investigate the kinetics of neutralizing antibodies (Nabs) against SARS-CoV-2 up to six months after the second vaccination dose with the BNT162b2 mRNA vaccine. Nabs levels were measured on days 1 (before the first vaccine shot), 8, 22 (before the second shot), 36, 50, and 3 and 6 months after the second vaccination (NCT04743388). Three hundred and eight healthy individuals without malignant disease were included in this study. At six months, 2.59% of the participants had a Nabs value less than 30%, while 11.9% had Nabs values of less than 50%. Importantly, 58% of the subjects had Nabs values of more than 75%. Nabs were initially eliminated at a relatively slow rate, but after three months their elimination was 5.7 times higher. Older age was inversely associated with Nabs levels at all examined timepoints. Interestingly, a population modeling analysis estimated that half of the subjects will have Nabs values less than 73.8% and 64.6% at 9 and 12 months, respectively, post vaccination completion. In conclusion, we found a persistent but declining anti-SARS-CoV-2 humoral immunity at six months following full vaccination with BNT162b2 in healthy individuals, which was more pronounced among older persons. These data may inform the public health policies regarding the prioritization of booster vaccine shots.

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