scholarly journals Phage-like particle vaccines are highly immunogenic and protect against pathogenic coronavirus infection and disease

2021 ◽  
Author(s):  
Bennett J Davenport ◽  
Alexis Catala ◽  
Stuart M Weston ◽  
Robert M Johnson ◽  
Jeremy Ardunay ◽  
...  

The response by vaccine developers to the COVID-19 pandemic has been extraordinary with effective vaccines authorized for emergency use in the U.S. within one year of the appearance of the first COVID-19 cases. However, the emergence of SARS-CoV-2 variants and obstacles with the global rollout of new vaccines highlight the need for platforms that are amenable to rapid tuning and stable formulation to facilitate the logistics of vaccine delivery worldwide. We developed a designer nanoparticle platform using phage-like particles (PLPs) derived from bacteriophage lambda for multivalent display of antigens in rigorously defined ratios. Here, we engineered PLPs that display the receptor binding domain (RBD) protein from SARS-CoV-2 and MERS-CoV, alone (RBD-SARS-PLPs, RBD-MERS-PLPs) and in combination (hCoV-RBD PLPs). Functionalized particles possess physiochemical properties compatible with pharmaceutical standards and retain antigenicity. Following primary immunization, BALB/c mice immunized with RBD-SARS- or RBD-MERS-PLPs display serum RBD-specific IgG endpoint and live virus neutralization titers that, in the case of SARS-CoV-2, were comparable to those detected in convalescent plasma from infected patients. Further, these antibody levels remain elevated up to 6 months post-prime. In dose response studies, immunization with as little as one microgram of RBD-SARS-PLPs elicited robust neutralizing antibody responses. Finally, animals immunized with RBD-SARS-PLPs, RBD-MERS-PLPs, and hCoV-RBD PLPs were protected against SARS-CoV-2 and/or MERS-CoV lung infection and disease. Collectively, these data suggest that the designer PLP system provides a platform for facile and rapid generation of single and multi-target vaccines.

Author(s):  
Mehul S Suthar ◽  
Matthew Zimmerman ◽  
Robert Kauffman ◽  
Grace Mantus ◽  
Susanne Linderman ◽  
...  

SARS-CoV-2 is currently causing a devastating pandemic and there is a pressing need to understand the dynamics, specificity, and neutralizing potency of the humoral immune response during acute infection. Herein, we report the dynamics of antibody responses to the receptor-binding domain (RBD) of the spike protein and virus neutralization activity in 44 COVID-19 patients. RBD-specific IgG responses were detectable in all patients 6 days after PCR confirmation. Using a clinical isolate of SARS-CoV-2, neutralizing antibody titers were also detectable in all patients 6 days after PCR confirmation. The magnitude of RBD-specific IgG binding titers correlated strongly with viral neutralization. In a clinical setting, the initial analysis of the dynamics of RBD-specific IgG titers was corroborated in a larger cohort of PCR-confirmed patients (n=231). These findings have important implications for our understanding of protective immunity against SARS-CoV-2, the use of immune plasma as a therapy, and the development of much-needed vaccines.


Author(s):  
Renata Varnaitė ◽  
Marina García ◽  
Hedvig Glans ◽  
Kimia T. Maleki ◽  
John Tyler Sandberg ◽  
...  

AbstractCoronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in late 2019 and has since become a global pandemic. Pathogen-specific antibodies are typically a major predictor of protective immunity, yet B cell and antibody responses during COVID-19 are not fully understood. Here, we analyzed antibody-secreting cell (ASC) and antibody responses in twenty hospitalized COVID-19 patients. The patients exhibited typical symptoms of COVID-19, and presented with reduced lymphocyte numbers and increased T cell and B cell activation. Importantly, we detected an expansion of SARS-CoV-2 nucleocapsid protein-specific ASCs in all twenty COVID-19 patients using a multicolor FluoroSpot assay. Out of the 20 patients, 16 had developed SARS-CoV-2-neutralizing antibodies by the time of inclusion in the study. SARS-CoV-2-specific IgA, IgG and IgM antibody levels positively correlated with SARS-CoV-2-neutralizing antibody titers, suggesting that SARS-CoV-2-specific antibody levels may reflect the titers of neutralizing antibodies in COVID-19 patients during the acute phase of infection. Lastly, we showed that interleukin 6 (IL-6) and C-reactive protein (CRP) concentrations were higher in serum of patients who were hospitalized for longer, supporting the recent observations that IL-6 and CRP could be used to predict COVID-19 severity. Altogether, this study constitutes a detailed description of clinical and immunological parameters in twenty COVID-19 patients, with a focus on B cell and antibody responses, and provides tools to study immune responses to SARS-CoV-2 infection and vaccination.


2021 ◽  
Author(s):  
Simon Jochum ◽  
Imke Kirste ◽  
Sayuri Hortsch ◽  
Veit Peter Grunert ◽  
Holly Legault ◽  
...  

Background The ability to quantify an immune response after vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential. This study assessed the clinical utility of the quantitative Roche Elecsys® Anti-SARS-CoV-2 S assay (ACOV2S) using samples from the 2019-nCoV vaccine (mRNA-1273) phase 1 trial (NCT04283461). Methods Samples from 30 healthy participants, aged 18-55 years, who received two injections with mRNA-1273 at a dose of 25 μg (n=15) or 100 μg (n=15), were collected at Days 1 (first vaccination), 15, 29 (second vaccination), 43 and 57. ACOV2S results (shown in U/mL - equivalent to BAU/mL per the first WHO international standard) were compared with results from ELISAs specific to antibodies against the Spike protein (S-2P) and the receptor binding domain (RBD) as well as neutralization tests including nanoluciferase (nLUC80), live-virus (PRNT80), and a pseudovirus neutralizing antibody assay (PsVNA50). Results RBD-specific antibodies were already detectable by ACOV2S at the first time point of assessment (d15 after first vaccination), with seroconversion before in all but 2 participants (25 μg dose group); all had seroconverted by Day 29. Across all post-baseline visits, geometric mean concentration of antibody levels were 3.27-7.48-fold higher in the 100 μg compared with the 25 μg dose group. ACOV2S measurements were highly correlated with those from RBD ELISA (Pearson's r=0.938; p<0.0001) and S-2P ELISA (r=0.918; p<0.0001). For both ELISAs, heterogeneous baseline results and smaller increases in antibody levels following the second vs first vaccination compared with ACOV2S were observed. ACOV2S showed absence of any baseline noise indicating high specificity detecting vaccine-induced antibody response. Moderate-strong correlations were observed between ACOV2S and neutralization tests (nLUC80 r=0.933; PsVNA50, r=0.771; PRNT80, r=0.672; all p≤0.0001). Conclusion The Elecsys Anti-SARS-CoV-2 S assay (ACOV2S) can be regarded as a highly valuable method to assess and quantify the presence of RBD-directed antibodies against SARS-CoV-2 following vaccination, and may indicate the presence of neutralizing antibodies. As a fully automated and standardized method, ACOV2S could qualify as the method of choice for consistent quantification of vaccine-induced humoral response.


2020 ◽  
Author(s):  
Natalia Ruetalo ◽  
Ramona Businger ◽  
Karina Althaus ◽  
Simon Fink ◽  
Felix Ruoff ◽  
...  

The majority of infections with SARS-CoV-2 are asymptomatic or mild without the necessity of hospitalization. It is of importance to reveal if these patients develop an antibody response against SARS-CoV-2 and to define which antibodies confer virus neutralization. We conducted a comprehensive serological survey of 49 patients with a mild course of disease and quantified neutralizing antibody responses against a clinical SARS-CoV-2 isolate employing human cells as targets. Four patients (8%), even though symptomatic, did not develop antibodies against SARS-CoV-2 and two other patients (4%) were only positive in one of the six serological assays employed. For the remainder, antibody response against the S-protein correlated with serum neutralization whereas antibodies against the nucleocapsid were poor predictors of virus neutralization. Regarding neutralization, only six patients (12%) could be classified as highly neutralizers. Furthermore, sera from several individuals with fairly high antibody levels had only poor neutralizing activity. In addition, employing a novel serological Western blot system to characterize antibody responses against seasonal coronaviruses, we found that antibodies against the seasonal coronavirus 229E might contribute to SARS-CoV-2 neutralization. Altogether, we show that there is a wide breadth of antibody responses against SARS-CoV-2 in patients that differentially correlate with virus neutralization. This highlights the difficulty to define reliable surrogate markers for immunity against SARS-CoV-2.


2021 ◽  
Author(s):  
Alena J. Markmann ◽  
Natasa Giallourou ◽  
D. Ryan Bhowmik ◽  
Yixuan J. Hou ◽  
Aaron Lerner ◽  
...  

AbstractThe coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) has now caused over 2 million deaths worldwide and continues to expand. Currently, much is unknown about functionally neutralizing human antibody responses and durability to SARS-CoV-2. Using convalescent sera collected from 101 COVID-19 recovered individuals 21-212 days after symptom onset with forty-eight additional longitudinal samples, we measured functionality and durability of serum antibodies. We also evaluated associations between individual demographic and clinical parameters with functional neutralizing antibody responses to COVID-19. We found robust antibody durability out to six months, as well as significant positive associations with the magnitude of the neutralizing antibody response and male sex. We also show that SARS-CoV-2 convalescent neutralizing antibodies are higher in individuals with cardio-metabolic comorbidities.SignificanceIn this study we found that neutralizing antibody responses in COVID-19 convalescent individuals vary in magnitude but are durable and correlate well with RBD Ig binding antibody levels compared to other SARS-CoV-2 antigen responses. In our cohort, higher neutralizing antibody titers are independently and significantly associated with male sex compared to female sex. We also show for the first time, that higher convalescent antibody titers in male donors are associated with increased age and symptom grade. Furthermore, cardio-metabolic co-morbidities are associated with higher antibody titers independently of sex. Here, we present an in-depth evaluation of serologic, demographic, and clinical correlates of functional antibody responses and durability to SARS-CoV-2.


2021 ◽  
Author(s):  
Venkata-Viswanadh Edara ◽  
Lilin Lai ◽  
Malaya Sahoo ◽  
Katharine Floyd ◽  
Mamdouh Sibai ◽  
...  

SARS-CoV-2 has caused a devastating global pandemic. The recent emergence of SARS-CoV-2 variants that are less sensitive to neutralization by convalescent sera or vaccine-induced neutralizing antibody responses has raised concerns. A second wave of SARS-CoV-2 infections in India is leading to the expansion of SARS-CoV-2 variants. The B.1.617.1 variant has rapidly spread throughout India and to several countries throughout the world. In this study, using a live virus assay, we describe the neutralizing antibody response to the B.1.617.1 variant in serum from infected and vaccinated individuals. We found that the B.1.617.1 variant is 6.8-fold more resistant to neutralization by sera from COVID-19 convalescent and Moderna and Pfizer vaccinated individuals. Despite this, a majority of the sera from convalescent individuals and all sera from vaccinated individuals were still able to neutralize the B.1.617.1 variant. This suggests that protective immunity by the mRNA vaccines tested here are likely retained against the B.1.617.1 variant. As the B.1.617.1 variant continues to evolve, it will be important to monitor how additional mutations within the spike impact antibody resistance, viral transmission and vaccine efficacy.


2021 ◽  
Author(s):  
Wataru Ogura ◽  
Kouki Ohtsuka ◽  
Sachiko Matsuura ◽  
Takahiro Okuyama ◽  
Satsuki Matsushima ◽  
...  

Objective In Japan, healthcare workers (HCWs) are vaccinated against coronavirus disease (COVID-19) and other contagious viruses (measles, rubella, chickenpox, mumps, and hepatitis B) to prevent nosocomial infection. However, some do not produce sufficient antibodies after vaccination (low responders). This study investigated changes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody levels among HCWs after SARS-CoV-2 vaccination and assessed whether low responders produced adequate SARS-CoV-2 anti-spike and neutralizing antibodies. Methods We conducted a prospective cohort study of HCWs before and after vaccination with the BNT162b2 mRNA vaccine in a hospital in Tokyo, Japan. The HCWs received two doses of BNT162b2 vaccine, 3 weeks apart. Those whose antibody levels against previous antiviral vaccines did not reach protective antibody levels after receiving two doses were defined as low responders, whereas those who produced adequate antibodies were defined as normal responders. SARS-CoV-2 anti-spike antibodies were measured 11 times from before the first BNT162b2 vaccination to 5 months after the second vaccination. SARS-CoV-2 neutralizing antibody activity was measured twice in low responders, 1 week to 1 month and 5 months after the second vaccination. Results Fifty HCWs were included in the analytic cohort. After vaccination, SARS-CoV-2 anti-spike antibody was detectable in the samples from both responders at each timepoint, but the level was lower at 5 months than at 1 week after the second vaccination. Low responders had SARS-CoV-2 neutralizing antibody activity 1 week to 1 month after the second vaccination, which exceeded the positive threshold after 5 months. Conclusion After BNT162b2 vaccination, low responders acquired adequate SARS-CoV-2 anti-spike and SARS-CoV-2 neutralizing antibodies to prevent SARS-CoV-2. However, SARS-CoV-2 anti-spike antibody levels were lower at 5 months than at 1 week after the second dose of BNT162b2 vaccine in low and normal responders. Therefore, low responders should also receive a third dose of BNT162b2 vaccine.


2020 ◽  
Vol 1 (3) ◽  
pp. 100040 ◽  
Author(s):  
Mehul S. Suthar ◽  
Matthew G. Zimmerman ◽  
Robert C. Kauffman ◽  
Grace Mantus ◽  
Susanne L. Linderman ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thomas W. McDade ◽  
Alexis R. Demonbreun ◽  
Amelia Sancilio ◽  
Brian Mustanski ◽  
Richard T. D’Aquila ◽  
...  

AbstractTwo-dose messenger RNA vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are highly effective in preventing symptomatic COVID-19 infection. However, the durability of protection is not known, nor is the effectiveness against emerging viral variants. Additionally, vaccine responses may differ based on prior SARS-CoV-2 exposure history. To investigate protection against SARS-CoV-2 variants we measured binding and neutralizing antibody responses following both vaccine doses. We document significant declines in antibody levels three months post-vaccination, and reduced neutralization of emerging variants, highlighting the need to identify correlates of clinical protection to inform the timing of and indications for booster vaccination.


Sign in / Sign up

Export Citation Format

Share Document