Assessment of COVID-19 mRNA vaccination titer and side effects in healthy volunteers

Abstract Objectives An effective vaccine against SARS-CoV-2 is essential to mitigate the COVID-19 pandemic. In these several months, a number of groups have started to report humoral responses and side effects after BNT162b2 vaccinations. Although these reports demonstrate the safety and efficacy, further studies are warranted to verify these findings. Here we examined the levels of SARS-CoV-2 antibodies in Japanese healthy volunteers who underwent BNT162b2 vaccine, to assess the humoral responses and side effects. Methods Forty-one healthy volunteers’ samples were used for the measurement of SARS-CoV-2 antibodies with chemiluminescent assays against the Receptor Binding Domain (RBD) of the virus. We also measured the side effects of the vaccination. Results Although the levels of IgM varied, all participants were seronegative for IgM and IgG before vaccination, and both IgM and IgG were significantly increased after the vaccinations. We further analyzed the humoral responses in relation to age, and found that the IgG levels for 14 days and 35 days, and IgM levels for 14 days after vaccination showed clear declining trends with age. Commonly reported side effects in the participants were sore arm/pain (90.0%) after the first dose, and generalized weakness/fatigue (70.0%), fever (57.5%), and sore arm/pain (90.0%) after the second dose. Conclusions BNT162b2 vaccination generates sufficient production of IgG especially after the second dose, though the response decreases age-dependently. The high frequencies of generalized weakness/fatigue, fever, and sore arm/pain were not negligible, especially after the second dose. This may be associated with the age characteristics of the population.

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Induction of Potent and Durable Neutralizing Antibodies Against SARS-CoV-2 Using a Receptor Binding Domain-Based Immunogen

Frontiers in Immunology ◽

10.3389/fimmu.2021.637982 ◽

2021 ◽

Vol 12 ◽

Author(s):

Vikram Srivastava ◽

Ling Niu ◽

Kruttika S. Phadke ◽

Bryan H. Bellaire ◽

Michael W. Cho

Keyword(s):

Receptor Binding ◽

Neutralizing Antibodies ◽

Global Economy ◽

Severe Pneumonia ◽

Binding Domain ◽

Effective Vaccine ◽

Receptor Binding Domain ◽

Neutralization Titer ◽

Antibody Titers ◽

Binding Antibody

A novel betacoronavirus (SARS-CoV-2) that causes severe pneumonia emerged through zoonosis in late 2019. The disease, referred to as COVID-19, has an alarming mortality rate and it is having a devastating effect on the global economy and public health systems. A safe, effective vaccine is urgently needed to halt this pandemic. In this study, immunogenicity of the receptor binding domain (RBD) of spike (S) glycoprotein was examined in mice. Animals were immunized with recombinant RBD antigen intraperitoneally using three different adjuvants (Zn-chitosan, Alhydrogel, and Adju-Phos), and antibody responses were followed for over 5 months. Results showed that potent neutralizing antibodies (nAbs) can be induced with 70% neutralization titer (NT70) of ~14,580 against live, infectious viruses. Although antigen-binding antibody titers decreased gradually over time, sufficiently protective levels of nAbs persisted (NT80 >2,430) over the 5-month observation period. Results also showed that adjuvants have profound effects on kinetics of nAb induction, total antibody titers, antibody avidity, antibody longevity, and B-cell epitopes targeted by the immune system. In conclusion, a recombinant subunit protein immunogen based on the RBD is a highly promising vaccine candidate. Continued evaluation of RBD immunogenicity using different adjuvants and vaccine regimens could further improve vaccine efficacy.

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Stabilization of the SARS-CoV-2 Spike receptor-binding domain using deep mutational scanning and structure-based design

10.1101/2021.05.15.444222 ◽

2021 ◽

Author(s):

Daniel Ellis ◽

Natalie Brunette ◽

Katherine H. D. Crawford ◽

Alexandra C. Walls ◽

Minh N. Pham ◽

...

Keyword(s):

Receptor Binding ◽

Large Scale ◽

Protein S ◽

Binding Pocket ◽

Binding Domain ◽

Effective Vaccine ◽

Receptor Binding Domain ◽

Wild Type ◽

Vaccine Candidates ◽

Generation Vaccine

The unprecedented global demand for SARS-CoV-2 vaccines has demonstrated the need for highly effective vaccine candidates that are thermostable and amenable to large-scale manufacturing. Nanoparticle immunogens presenting the receptor-binding domain (RBD) of the SARS-CoV-2 Spike protein (S) in repetitive arrays are being advanced as second-generation vaccine candidates, as they feature robust manufacturing characteristics and have shown promising immunogenicity in preclinical models. Here, we used previously reported deep mutational scanning (DMS) data to guide the design of stabilized variants of the RBD. The selected mutations fill a cavity in the RBD that has been identified as a linoleic acid binding pocket. Screening of several designs led to the selection of two lead candidates that expressed at higher yields than the wild-type RBD. These stabilized RBDs possess enhanced thermal stability and resistance to aggregation, particularly when incorporated into an icosahedral nanoparticle immunogen that maintained its integrity and antigenicity for 28 days at 35-40°C, while corresponding immunogens displaying the wild-type RBD experienced aggregation and loss of antigenicity. The stabilized immunogens preserved the potent immunogenicity of the original nanoparticle immunogen, which is currently being evaluated in a Phase I/II clinical trial. Our findings may improve the scalability and stability of RBD-based coronavirus vaccines in any format and more generally highlight the utility of comprehensive DMS data in guiding vaccine design.

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Cloning, Expression and Biophysical Characterization of a Yeast-expressed Recombinant SARS-CoV-2 Receptor Binding Domain COVID-19 Vaccine Candidate

10.1101/2020.11.09.373449 ◽

2020 ◽

Cited By ~ 1

Author(s):

Wen-Hsiang Chen ◽

Junfei Wei ◽

Rakhi Tyagi Kundu ◽

Rakesh Adhikari ◽

Zhuyun Liu ◽

...

Keyword(s):

Receptor Binding ◽

Structural Changes ◽

Tertiary Structure ◽

Vaccine Development ◽

Glycosylation Site ◽

Binding Domain ◽

Effective Vaccine ◽

Receptor Binding Domain ◽

Biophysical Characterization ◽

Recombinant Receptor

ABSTRACTCoronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 has now spread worldwide to infect approximately 50 million people, with over 1 million reported deaths, and a safe and effective vaccine remains urgently needed. Based on previous experience developing vaccines against SARS and MERS, we constructed three variants of the recombinant receptor-binding domain (RBD) of the SARS-CoV-2 spike (S) protein (residues 331-549) in yeast as follows: (1) a “wild type” RBD (RBD219-WT), (2) a deglycosylated form (RBD219-N1) by deleting the first N-glycosylation site, and (3) a combined deglycosylated and cysteine (C538A-mutated variant (RBD219-N1C1)). We compared the expression yields, biophysical characteristics, and functionality of the proteins produced from these constructs. Collectively, these three recombinant protein RBDs showed similar secondary and tertiary structure thermal stability and had the same affinity for their receptor, angiotensin-converting enzyme 2 (ACE-2), suggesting that the selected deletion or mutations did not cause any significant structural changes or alteration of function. However, RBD219-N1C1 had a higher fermentation yield, was easier to purify, and had a lower tendency to form oligomers when compared to the other two proteins and was therefore selected for further vaccine development and evaluation.

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Attenuated Influenza Virions Expressing the SARS-CoV-2 Receptor-Binding Domain Induce Neutralizing Antibodies in Mice

Viruses ◽

10.3390/v12090987 ◽

2020 ◽

Vol 12 (9) ◽

pp. 987 ◽

Cited By ~ 2

Author(s):

Andrea N. Loes ◽

Lauren E. Gentles ◽

Allison J. Greaney ◽

Katharine H. D. Crawford ◽

Jesse D. Bloom

Keyword(s):

Influenza Virus ◽

Receptor Binding ◽

Neutralizing Antibodies ◽

Reverse Genetics ◽

Natural Infection ◽

Neutralizing Antibody ◽

Binding Domain ◽

Effective Vaccine ◽

Receptor Binding Domain ◽

Antibody Titers

An effective vaccine is essential for controlling the spread of the SARS-CoV-2 virus. Here, we describe an influenza virus-based vaccine for SARS-CoV-2. We incorporated a membrane-anchored form of the SARS-CoV-2 spike receptor binding domain (RBD) in place of the neuraminidase (NA) coding sequence in an influenza virus also possessing a mutation that reduces the affinity of hemagglutinin for its sialic acid receptor. The resulting ΔNA(RBD)-Flu virus can be generated by reverse genetics and grown to high titers in cell culture. A single-dose intranasal inoculation of mice with ΔNA(RBD)-Flu elicits serum neutralizing antibody titers against SAR-CoV-2 comparable to those observed in humans following natural infection (~1:200). Furthermore, ΔNA(RBD)-Flu itself causes no apparent disease in mice. It might be possible to produce a vaccine similar to ΔNA(RBD)-Flu at scale by leveraging existing platforms for the production of influenza vaccines.

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Stabilization of the SARS-CoV-2 Spike Receptor-Binding Domain Using Deep Mutational Scanning and Structure-Based Design

Frontiers in Immunology ◽

10.3389/fimmu.2021.710263 ◽

2021 ◽

Vol 12 ◽

Author(s):

Daniel Ellis ◽

Natalie Brunette ◽

Katharine H. D. Crawford ◽

Alexandra C. Walls ◽

Minh N. Pham ◽

...

Keyword(s):

Receptor Binding ◽

Large Scale ◽

Protein S ◽

Binding Pocket ◽

Binding Domain ◽

Effective Vaccine ◽

Receptor Binding Domain ◽

Wild Type ◽

Vaccine Candidates ◽

Generation Vaccine

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SARS-CoV-2 Receptor Binding Domain IgG Response to AstraZeneca (AZD1222) COVID-19 Vaccination, Jamaica

10.1101/2021.10.22.21265401 ◽

2021 ◽

Author(s):

Ynolde E Leys ◽

Magdalene Nwokocha ◽

Jerome P Walker ◽

Tiffany R Butterfield ◽

Velesha Frater ◽

...

Keyword(s):

Side Effects ◽

Receptor Binding ◽

Binding Domain ◽

Caribbean Region ◽

Receptor Binding Domain ◽

Vaccination Programs ◽

English Speaking ◽

Effective Use ◽

Igg Level ◽

Site Pain

The Caribbean region is lacking an assessment of the antibody response and side effects experienced after AstraZeneca COVID-19 vaccination (AZD1222). We examined SARS-CoV-2 spike receptor binding domain (RBD) IgG levels and reported side effects in a Jamaican population after AZD1222 vaccination. Median RBD IgG levels for persons without evidence of previous SARS-CoV-2 infection were 43.1 bIU/mL after 3-7 weeks post first dose, rising to 100.1 bIU/mL 3-7 weeks post second dose, and falling 46.9 bIU/mL 16-22 weeks post second dose. The median RBD IgG level 2-8 weeks after symptom onset for unvaccinated SARS-CoV-2 infected persons of all disease severities was 411.6 bIU/mL. Common AZD1222 side effects after first dose were injection site pain, headache and chills. Most persons reported no side effects after second dose. AZD1222 is widely used across the English-speaking Caribbean and the study provides evidence for its continued safe and effective use in vaccination programs.

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Glycan engineering of the SARS-CoV-2 receptor-binding domain elicits cross-neutralizing antibodies for SARS-related viruses

Journal of Experimental Medicine ◽

10.1084/jem.20211003 ◽

2021 ◽

Vol 218 (12) ◽

Author(s):

Ryo Shinnakasu ◽

Shuhei Sakakibara ◽

Hiromi Yamamoto ◽

Po-hung Wang ◽

Saya Moriyama ◽

...

Keyword(s):

Receptor Binding ◽

Germinal Center ◽

Neutralizing Antibodies ◽

Binding Domain ◽

Antibody Responses ◽

Binding Motif ◽

Receptor Binding Domain ◽

The Core ◽

Humoral Responses ◽

Conserved Core

Broadly protective vaccines against SARS-related coronaviruses that may cause future outbreaks are urgently needed. The SARS-CoV-2 spike receptor-binding domain (RBD) comprises two regions, the core-RBD and the receptor-binding motif (RBM); the former is structurally conserved between SARS-CoV-2 and SARS-CoV. Here, in order to elicit humoral responses to the more conserved core-RBD, we introduced N-linked glycans onto RBM surfaces of the SARS-CoV-2 RBD and used them as immunogens in a mouse model. We found that glycan addition elicited higher proportions of the core-RBD–specific germinal center (GC) B cells and antibody responses, thereby manifesting significant neutralizing activity for SARS-CoV, SARS-CoV-2, and the bat WIV1-CoV. These results have implications for the design of SARS-like virus vaccines.

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Plant-Produced Receptor-Binding Domain of SARS-CoV-2 Elicits Potent Neutralizing Responses in Mice and Non-human Primates

Frontiers in Plant Science ◽

10.3389/fpls.2021.682953 ◽

2021 ◽

Vol 12 ◽

Author(s):

Konlavat Siriwattananon ◽

Suwimon Manopwisedjaroen ◽

Balamurugan Shanmugaraj ◽

Kaewta Rattanapisit ◽

Supaporn Phumiamorn ◽

...

Keyword(s):

Receptor Binding ◽

Protein A ◽

Binding Domain ◽

Effective Vaccine ◽

Affinity Column ◽

Receptor Binding Domain ◽

Global Public Health ◽

A Subunit ◽

Human Igg1 ◽

Lymphocyte Responses

The emergence of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected global public health and economy. Despite the substantial efforts, only few vaccines are currently approved and some are in the different stages of clinical trials. As the disease rapidly spreads, an affordable and effective vaccine is urgently needed. In this study, we investigated the immunogenicity of plant-produced receptor-binding domain (RBD) of SARS-CoV-2 in order to use as a subunit vaccine. In this regard, RBD of SARS-CoV-2 was fused with Fc fragment of human IgG1 and transiently expressed in Nicotiana benthamiana by agroinfiltration. The plant-produced RBD-Fc fusion protein was purified from the crude extract by using protein A affinity column chromatography. Two intramuscular administration of plant-produced RBD-Fc protein formulated with alum as an adjuvant have elicited high neutralization titers in immunized mice and cynomolgus monkeys. Further it has induced a mixed Th1/Th2 immune responses and vaccine-specific T-lymphocyte responses which was confirmed by interferon-gamma (IFN-γ) enzyme-linked immunospot assay. Altogether, our results demonstrated that the plant-produced SARS-CoV-2 RBD has the potential to be used as an effective vaccine candidate against SARS-CoV-2. To our knowledge, this is the first report demonstrating the immunogenicity of plant-produced SARS-CoV-2 RBD protein in mice and non-human primates.

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Attenuated influenza virions expressing the SARS-CoV-2 receptor-binding domain induce neutralizing antibodies in mice

10.1101/2020.08.12.248823 ◽

2020 ◽

Author(s):

Andrea N. Loes ◽

Lauren E. Gentles ◽

Allison J. Greaney ◽

Katharine H. D. Crawford ◽

Jesse D. Bloom

Keyword(s):

Influenza Virus ◽

Receptor Binding ◽

Neutralizing Antibodies ◽

Reverse Genetics ◽

Natural Infection ◽

Neutralizing Antibody ◽

Binding Domain ◽

Effective Vaccine ◽

Receptor Binding Domain ◽

Antibody Titers

AbstractAn effective vaccine is essential to controlling the spread of SARS-CoV-2 virus. Here, we describe an influenza-virus-based vaccine for SARS-CoV-2. We incorporated a membrane-anchored form of the SARS-CoV-2 Spike receptor binding domain (RBD) in place of the neuraminidase (NA) coding sequence in an influenza virus also possessing a mutation that reduces the affinity of hemagglutinin for its sialic acid receptor. The resulting ΔNA(RBD)-Flu virus can be generated by reverse genetics and grown to high titers in cell culture. A single-dose intranasal inoculation of mice with ΔNA(RBD)-Flu elicits serum neutralizing antibody titers against SAR-CoV-2 comparable to those observed in humans following natural infection (∼1:200). Furthermore, ΔNA(RBD)-Flu itself causes no apparent disease in mice. It might be possible to produce a vaccine similar to ΔNA(RBD)-Flu at scale by leveraging existing platforms for production of influenza vaccines.

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Implications for SARS-CoV-2 Vaccine Design: Fusion of Spike Glycoprotein Transmembrane Domain to Receptor-Binding Domain Induces Trimerization

Membranes ◽

10.3390/membranes10090215 ◽

2020 ◽

Vol 10 (9) ◽

pp. 215 ◽

Cited By ~ 1

Author(s):

Taha Azad ◽

Ragunath Singaravelu ◽

Mathieu J.F. Crupi ◽

Taylor Jamieson ◽

Jaahnavi Dave ◽

...

Keyword(s):

Receptor Binding ◽

Transmembrane Domain ◽

Vaccine Development ◽

Binding Domain ◽

Effective Vaccine ◽

Therapeutic Drug ◽

Receptor Binding Domain ◽

Design Strategies ◽

Protein Receptor

The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic presents an urgent need for an effective vaccine. Molecular characterization of SARS-CoV-2 is critical to the development of effective vaccine and therapeutic strategies. In the present study, we show that the fusion of the SARS-CoV-2 spike protein receptor-binding domain to its transmembrane domain is sufficient to mediate trimerization. Our findings may have implications for vaccine development and therapeutic drug design strategies targeting spike trimerization. As global efforts for developing SARS-CoV-2 vaccines are rapidly underway, we believe this observation is an important consideration for identifying crucial epitopes of SARS-CoV-2.

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