scholarly journals Immune responses to inactivated and vector-based vaccines in individuals previously infected with SARS-CoV-2

2022 ◽  
Author(s):  
Nungruthai Suntronwong ◽  
Ritthideach Yorsaeng ◽  
Chompoonut Auphimai ◽  
Thanunrat Thongmee ◽  
Preeyaporn Vichaiwattana ◽  
...  
Keyword(s):  
Immune Response ◽  
Single Dose ◽  
Immune Responses ◽  
Antibody Response ◽  
Specific Binding ◽  
Specific Antibodies ◽  
Neutralizing Activity ◽  
Cell Responses ◽  
Interferon Gamma Response ◽  
Dose Vaccine

AbstractImmunity wanes in individuals previously infected with SARS-CoV-2, and vaccinating those individuals may help reduce reinfection. Herein, reactogenicity and immunogenicity following vaccination with inactivated (CoronaVac) and vector-based (ChAdOx1-S, AZD1222) vaccines were examined in previously infected individuals. Immune response was also compared between short and long intervals between first date of detection and vaccination. Adverse events were mild but were higher with AZD1222 than with CoronaVac. Baseline IgG-specific antibodies and neutralizing activity were significantly higher with shorter than longer intervals. With a single-dose vaccine, IgG and IgA-specific binding antibodies, neutralizing activity, and total interferon-gamma response peaked at 14 days. Immune response was significantly higher in recovered individuals than in infection-naïve individuals. Antibody response was greater with longer than shorter intervals. AZD1222 induced higher antibody and T cell responses than those of CoronaVac. Thus, to achieve immunity, individuals with prior SARS-CoV-2 exposure may require only a single dose of AZD1222 or two doses of CoronaVac to achieve the immune response. These findings supported vaccine strategies in previously infected individuals.

scholarly journals Boosting of the SARS-CoV-2-specific immune response after vaccination with single-dose Sputnik Light vaccine

2021 ◽  
Author(s):  
Alexey A. Komissarov ◽  
Inna V. Dolzhikova ◽  
Grigory A. Efimov ◽  
Denis Y. Logunov ◽  
Olga Mityaeva ◽  
...  
Keyword(s):  
Immune Response ◽  
Single Dose ◽  
T Cell ◽  
Immune Responses ◽  
Antibody Response ◽  
Strong Correlation ◽  
Post Vaccination ◽  
Cell Responses ◽  
Novel Variants ◽  
Specific Igg

AbstractDespite the measures taken worldwide, COVID-19 pandemic still progresses. While efficient antiviral drugs are not yet widely available, vaccination is the best option to control the infection rate. Although this option is obvious in case of COVID-19–naïve individuals, it is still unclear when individuals who have recovered from a previous SARS-CoV-2 infection should be vaccinated and whether the vaccination raises immune responses against the coronavirus and its novel variants. Here we measured the dynamics of the antibody and T-cell responses, as well as virus neutralizing activity (VNA) in serum against two SARS-CoV-2 variants, B.1.1.1 and B.1.617.2, among 84 individuals with different COVID-19 status who were vaccinated with Sputnik Light vaccine. We showed that vaccination of individuals previously exposed to the virus considerably boosts the existing immune response. In these individuals, RBD-specific IgG titers and VNA in serum were already elevated on the 7th day after vaccination, while COVID-19–naïve individuals developed the antibody response and VNA mainly 21 days post–vaccination. Additionally, we found a strong correlation between RBD-specific IgG titers and VNA in serum, and according to these data vaccination may be recommended if the RBD-specific IgG titers drop to 142.7 BAU/mL or below. In summary, the results of the study demonstrate that vaccination is beneficial both for COVID-19–naïve and recovered individuals, especially since it raises serum VNA against the B.1.617.2 variant – one of four the SARS-CoV-2 variants of concern.

scholarly journals Immune responses following the first dose of the Sputnik V (Gam-COVID-Vac)

2021 ◽  
Author(s):  
Chandima Jeewandara ◽  
Harsha Fernando ◽  
Pradeep Pushpakumara ◽  
Shyrar Tanussiya ◽  
Achala Kamaladasa ◽  
...  
Keyword(s):  
Single Dose ◽  
Immune Responses ◽  
High Frequency ◽  
Ex Vivo ◽  
Natural Infection ◽  
Receptor Binding Domain ◽  
Cell Responses ◽  
Blocking Antibodies ◽  
With Memory ◽  
Dose Vaccine

Abstract As the first dose of Gam-COVID-Vac, is currently used as a single dose vaccine in some countries, we investigated the immunogenicity of this at 4 weeks (327 naïve individuals). 88.7% seroconverted, with significantly lower seroconversion rates in those over 60 years (p = 0.004) and significantly lower than previously seen with AZD1222 (p = 0.018). 82.6% developed ACE2 receptor blocking antibodies, although levels were significantly lower than following natural infection (p = 0.0009) and a single dose of AZD1222 (p < 0.0001). Similar titres of antibodies were observed to the receptor binding domain of WT, B.1.1.7 and B.1.617.2 compared to AZD1222, while the levels for B.1.351 were significantly higher (p = 0.006) for Gam-COVID-Vac. 30% developed ex vivo IFNγ ELISpot responses (significantly lower than AZD1222), and high frequency of CD107a expressing T cells along with memory B cell responses. Although single dose of Gam-COVID-Vac was highly immunogenic, administration of a second dose is likely to be beneficial.

scholarly journals Immune responses following the first dose of the Sputnik V (Gam-COVID-Vac)

2021 ◽  
Author(s):  
Gathsaurie Malavige ◽  
Chandima Jeewandara ◽  
Harsha Fernando ◽  
Pradeep Darshana Pushpakumara ◽  
Shyrar Tanussiya ◽  
...  
Keyword(s):  
Single Dose ◽  
Immune Responses ◽  
High Frequency ◽  
Ex Vivo ◽  
Natural Infection ◽  
Receptor Binding Domain ◽  
Cell Responses ◽  
Blocking Antibodies ◽  
With Memory ◽  
Dose Vaccine

Abstract As the first dose of Gam-COVID-Vac, is currently used as a single dose vaccine in some countries, we investigated the immunogenicity of this at 4 weeks (327 naïve individuals). 88.7% seroconverted, with significantly lower seroconversion rates in those over 60 years (p = 0.004) and significantly lower than previously seen with AZD1222 (p = 0.018). 82.6% developed ACE2 receptor blocking antibodies, although levels were significantly lower than following natural infection (p = 0.0009) and a single dose of AZD1222 (p < 0.0001). Similar titres of antibodies were observed to the receptor binding domain of WT, B.1.1.7 and B.1.617.2 compared to AZD1222, while the levels for B.1.351 were significantly higher (p = 0.006) for Gam-COVID-Vac. 30% developed ex vivo IFNγ ELISpot responses (significantly lower than AZD1222), and high frequency of CD107a expressing T cells along with memory B cell responses. Although single dose of Gam-COVID-Vac was highly immunogenic, administration of a second dose is likely to be beneficial.

scholarly journals Optimized Adenovirus-Antibody Complexes Stimulate Strong Cellular and Humoral Immune Responses against an Encoded Antigen in Naïve Mice and Those with Preexisting Immunity

2011 ◽  
Vol 19 (1) ◽  
pp. 84-95 ◽  
Author(s):  
Jin Huk Choi ◽  
Joe Dekker ◽  
Stephen C. Schafer ◽  
Jobby John ◽  
Craig E. Whitfill ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
T Cell Responses ◽  
Transduction Efficiency ◽  
Virus Antibody ◽  
Cell Responses

ABSTRACTThe immune response to recombinant adenoviruses is the most significant impediment to their clinical use for immunization. We test the hypothesis that specific virus-antibody combinations dictate the type of immune response generated against the adenovirus and its transgene cassette under certain physiological conditions while minimizing vector-induced toxicity.In vitroandin vivoassays were used to characterize the transduction efficiency, the T and B cell responses to the encoded transgene, and the toxicity of 1 × 1011adenovirus particles mixed with different concentrations of neutralizing antibodies. Complexes formed at concentrations of 500 to 0.05 times the 50% neutralizing dose (ND50) elicited strong virus- and transgene-specific T cell responses. The 0.05-ND50formulation elicited measurable anti-transgene antibodies that were similar to those of virus alone (P= 0.07). This preparation also elicited very strong transgene-specific memory T cell responses (28.6 ± 5.2% proliferation versus 7.7 ± 1.4% for virus alone). Preexisting immunity significantly reduced all responses elicited by these formulations. Although lower concentrations (0.005 and 0.0005 ND50) of antibody did not improve cellular and humoral responses in naïve animals, they did promote strong cellular (0.005 ND50) and humoral (0.0005 ND50) responses in mice with preexisting immunity. Some virus-antibody complexes may improve the potency of adenovirus-based vaccines in naïve individuals, while others can sway the immune response in those with preexisting immunity. Additional studies with these and other virus-antibody ratios may be useful to predict and model the type of immune responses generated against a transgene in those with different levels of exposure to adenovirus.

scholarly journals Immunogenicity of mRNA-1273, BNT162b2 and Ad26.COV2.S COVID-19 vaccines

2021 ◽  
Author(s):  
Vivek Naranbhai ◽  
Wilfredo F Garcia-Beltran ◽  
Christhian Berrios Mairena ◽  
Julia Cara Thierauf ◽  
Christina Catherine Chang ◽  
...  
Keyword(s):  
Single Dose ◽  
T Cell ◽  
Immune Responses ◽  
T Cell Responses ◽  
Control Groups ◽  
Neutralization Titer ◽  
Cell Responses ◽  
Effectiveness Studies ◽  
Prior Infection ◽  
Repeat Sampling

Background: Understanding variation in immunogenicity may help rationalize use of existing SARS-CoV-2 vaccines. Methods: We compared immune responses in ambulatory adults vaccinated with mRNA-1273 , BNT-162b2 or Ad26.COV2.S in Massachusetts, USA between February and May 2021. Control groups were pre-pandemic controls (n=1220) and individuals without (n=112) or with prior SARS-CoV-2 infection (n=130) sampled in mid-2020. We measured total anti-spike IgG/M/A antibodies (Roche Elecsys Anti-SARS-COV-2 S assay), anti-receptor-binding-domain (RBD) antibodies; neutralization of SARS-CoV-2 pseudovirus; and T-cell responses. Findings In individuals with prior infection, all vaccines were associated with higher antibody concentrations and neutralization than those in convalescent individuals, even after a single dose. In individuals without prior infection, a single dose of either mRNA vaccine yielded comparable concentrations and neutralization to convalescent unvaccinated individuals, and Ad26.COV2.S yielded lower antibody concentrations and neutralization titers. The second dose of either mRNA vaccine boosted responses. At a median of 24 days after vaccination, two of 21 (9.5%) Ad26.COV2.S recipients had a neutralization titer higher than pre-pandemic controls; repeat sampling at a median 66 days after vaccination found most (11/15 (73%) remained negative. Antibody concentrations and neutralization titers increased similarly after the first dose of either vaccine, and even further in recipients of a second dose of vaccine. T-cell responses were higher in mRNA1273 and BNT162b2 than Ad26.COV2.S recipients. Interpretation SARS-CoV-2 vaccines vary significantly in immunogenicity in individuals without prior infection. If confirmed in effectiveness studies, public health policy may need to be tailored to each vaccine, or even individual responses.

scholarly journals Robust SARS-CoV-2-specific T-cell immunity is maintained at 6 months following primary infection

2020 ◽  
Author(s):  
Jianmin Zuo ◽  
Alex Dowell ◽  
Hayden Pearce ◽  
Kriti Verma ◽  
Heather Long ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Immune Responses ◽  
Antibody Level ◽  
Primary Infection ◽  
Natural Infection ◽  
T Cell Responses ◽  
Symptomatic Infection ◽  
Cell Responses ◽  
Cell Immunity

Abstract The immune response to SARS-CoV-2 is critical in both controlling primary infection and preventing re-infection. However, there is concern that immune responses following natural infection may not be sustained and that this may predispose to recurrent infection. We analysed the magnitude and phenotype of the SARS-CoV-2 cellular immune response in 100 donors at six months following primary infection and related this to the profile of antibody level against spike, nucleoprotein and RBD over the previous six months. T-cell immune responses to SARS-CoV-2 were present by ELISPOT or ICS analysis in all donors and are characterised by predominant CD4+ T cell responses with strong IL-2 cytokine expression. Median T-cell responses were 50% higher in donors who had experienced an initial symptomatic infection indicating that the severity of primary infection establishes a ‘setpoint’ for cellular immunity that lasts for at least 6 months. The T-cell responses to both spike and nucleoprotein/membrane proteins were strongly correlated with the peak antibody level against each protein. The rate of decline in antibody level varied between individuals and higher levels of nucleoprotein-specific T cells were associated with preservation of NP-specific antibody level although no such correlation was observed in relation to spike-specific responses. In conclusion, our data are reassuring that functional SARS-CoV-2-specific T-cell responses are retained at six months following infection although the magnitude of this response is related to the clinical features of primary infection.

Rhamnose modified bovine serum albumin as a carrier protein promotes the immune response against sTn antigen

2020 ◽  
Vol 56 (90) ◽  
pp. 13959-13962
Author(s):  
Han Lin ◽  
Haofei Hong ◽  
Jinfeng Wang ◽  
Chen Li ◽  
Zhifang Zhou ◽  
...  
Keyword(s):  
Immune Response ◽  
Bovine Serum Albumin ◽  
Immune Responses ◽  
Serum Albumin ◽  
Cancer Vaccine ◽  
Bovine Serum ◽  
Vaccine Development ◽  
Carrier Protein ◽  
Antigen Uptake ◽  
Specific Antibodies

Rhamnose and sTn antigen were co-conjugated to bovine serum albumin (BSA) for cancer vaccine development. The immune responses against sTn have been significantly augmented with the involvement of Rha-specific antibodies to enhance antigen uptake.

scholarly journals Simultaneous Immunization with Multivalent Norovirus VLPs Induces Better Protective Immune Responses to Norovirus than Sequential Immunization

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1018
Author(s):  
Maria Malm ◽  
Timo Vesikari ◽  
Vesna Blazevic
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Antibody Response ◽  
Vaccine Candidate ◽  
Serum Antibodies ◽  
Blocking Antibody ◽  
Alternative Approach ◽  
Sequential Boost ◽  
Trivalent Vaccine ◽  
Rotavirus Vp6

Human noroviruses (NoVs) are a genetically diverse, constantly evolving group of viruses. Here, we studied the effect of NoV pre-existing immunity on the success of NoV vaccinations with genetically close and distant genotypes. A sequential immunization as an alternative approach to multivalent NoV virus-like particles (VLPs) vaccine was investigated. Mice were immunized with NoV GI.3, GII.4-1999, GII.17, and GII.4 Sydney as monovalent VLPs or as a single tetravalent mixture combined with rotavirus VP6-protein. Sequentially immunized mice were primed with a trivalent vaccine candidate (GI.3 + GII.4-1999 + VP6) and boosted, first with GII.17 and then with GII.4 Sydney VLPs. NoV serum antibodies were analyzed. Similar NoV genotype-specific immune responses were induced with the monovalent and multivalent mixture immunizations, and no immunological interference was observed. Multivalent immunization with simultaneous mix was found to be superior to sequential immunization, as sequential boost induced strong blocking antibody response against the distant genotype (GII.17), but not against GII.4 Sydney, closely related to GII.4-1999, contained in the priming vaccine. Genetically close antigens may interfere with the immune response generation and thereby immune responses may be differently formed depending on the degree of NoV VLP genotype identity.

scholarly journals Nature and Specificity of the Required Protective Immune Response That Develops Postchallenge in Mice Vaccinated with the 19-Kilodalton Fragment of Plasmodium yoelii Merozoite Surface Protein 1

2002 ◽  
Vol 70 (11) ◽  
pp. 6013-6020 ◽  
Author(s):  
Jiraprapa Wipasa ◽  
Huji Xu ◽  
Morris Makobongo ◽  
Michelle Gatton ◽  
Anthony Stowers ◽  
...  
Keyword(s):  
Immune Response ◽  
Antibody Response ◽  
Specific Antibody ◽  
Natural Infection ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Plasmodium Yoelii ◽  
Specific Antibody Response ◽  
Specific Antibodies ◽  
Merozoite Surface Protein 1

ABSTRACT Immunity induced by the 19-kDa fragment of Plasmodium yoelii merozoite surface protein 1 (MSP119) is dependent on high titers of specific antibodies present at the time of challenge and a continuing active immune response postinfection. However, the specificity of the active immune response postinfection has not been defined. In particular, it is not known whether anti-MSP119 antibodies that arise following infection alone are sufficient for protection. We developed systems to investigate whether an MSP119-specific antibody response alone both prechallenge and postchallenge is sufficient for protection. We were able to exclude antibodies with other specificities, as well as any contribution of MSP119-specific CD4+ T cells acting independent of antibody, and we concluded that an immune response focused solely on MSP119-specific antibodies is sufficient for protection. The data imply that the ability of natural infection to boost an MSP119-specific antibody response should greatly improve vaccine efficacy.

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.

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