scholarly journals Safety and immunogenicity of a heterologous booster of protein subunit vaccine MVC-COV1901 after two doses of adenoviral vector vaccine AZD1222

2021 ◽  
Author(s):  
Shu-Hsing Cheng ◽  
Yi-Chun Lin ◽  
Cheng-Pin Chen ◽  
Chien-Yu Cheng
Keyword(s):  
Adenoviral Vector ◽  
Subunit Vaccine ◽  
Booster Dose ◽  
Neutralizing Antibody ◽  
Protein Subunit ◽  
Igg Antibody ◽  
Vector Vaccine ◽  
Antibody Titers

We report the interim safety and immunogenicity results in participants administrated with a booster dose of protein subunit vaccine MVC-COV1901 at 12 or 24 weeks after two doses of AZD1222 (ChAdOx1 nCoV-19). In subjects fully vaccinated with two doses of AZD1222, waning antibody immunity was apparent within six months of the second dose of AZD1222. At one month after the MVC-COV1901 booster dose, anti-SARS-CoV-2 spike IgG antibody titers and neutralizing antibody titers were 14- and 8.6-fold increased, respectively, when compared to the titer levels on the day of the booster dose. These interim results support the use of MVC-COV1901 as a heterologous booster for individuals vaccinated with AZD1222.

scholarly journals The reactogenicity and immunogenicity of a booster dose after the second dose of a protein subunit vaccine MVC-COV1901

2021 ◽  
Author(s):  
Szu-Min Hsieh ◽  
Shan-chwen Chang ◽  
Hao-Yuan Cheng ◽  
Shin-Ru Shih ◽  
Chia En Lien
Keyword(s):  
Clinical Study ◽  
Antibody Titer ◽  
Subunit Vaccine ◽  
Booster Dose ◽  
Phase 1 ◽  
Neutralizing Antibody ◽  
Dose Schedule ◽  
Protein Subunit ◽  
Antibody Persistence

AbstractIn this extension of the phase 1 clinical study, we report the immunogenicity and reactogenicity of the booster dose of a COVID-19 vaccine, MVC-COV1901, administered six months after the completion of the primary two dose schedule. Antibody persistence was detected at 6 months after the second dose of MVC-COV1901, albeit at reduced levels. At 28 days after the booster dose, the neutralizing antibody titer was 1.7-fold higher compared to the previous peak at 2 weeks after the second dose. These data demonstrated the safety and immunogenicity of booster shot of MVC-COV1901 after the primary schedule of the vaccine.

scholarly journals Comparison of Neutralizing Antibody Titers Elicited by mRNA and Adenoviral Vector Vaccine against SARS-CoV-2 Variants

2021 ◽  
Author(s):  
Takuya Tada ◽  
Hao Zhou ◽  
Marie I Samanovic ◽  
Belinda M Dcosta ◽  
Amber Cornelius ◽  
...  
Keyword(s):  
Vaccine Efficacy ◽  
Adenoviral Vector ◽  
Neutralizing Antibody ◽  
Significant Fraction ◽  
Vector Vaccine ◽  
Antibody Titers

The increasing prevalence of SARS-CoV-2 variants has raised concerns regarding possible decreases in vaccine efficacy. Here, neutralizing antibody titers elicited by mRNA-based and an adenoviral vector-based vaccine against variant pseudotyped viruses were compared. BNT162b2 and mRNA-1273-elicited antibodies showed modest neutralization resistance against Beta, Delta, Delta plus and Lambda variants whereas Ad26.COV2.S-elicited antibodies from a significant fraction of vaccinated individuals were of low neutralizing titer (IC50 <50). The data underscore the importance of surveillance for breakthrough infections that result in severe COVID-19 and suggest the benefit of a second immunization following Ad26.COV2.S to increase protection against the variants.

scholarly journals Protection of Hamsters Challenged with SARS-CoV-2 Variants of Concern by Two Doses of MVC-COV1901 Vaccine Followed by a Single Dose of Beta Variant Version of MVC-COV1901

2021 ◽  
Author(s):  
Tsun-Yung Kuo ◽  
Chia-En Lien ◽  
Yi-Jiun Lin ◽  
Meei-Yun Lin ◽  
Chung-Chin Wu ◽  
...  
Keyword(s):  
Subunit Vaccine ◽  
Virus Titer ◽  
Neutralizing Antibody ◽  
Protein S ◽  
Protein Subunit ◽  
Live Virus ◽  
The Third ◽  
Severity Of Disease ◽  
Potent Immune Response ◽  
Ancestral Strain

AbstractThe current fight against COVID-19 is compounded by the Variants of Concern (VoCs), which can diminish the effectiveness of vaccines, increase viral transmission and severity of disease. MVC-COV1901 is a protein subunit vaccine based on the prefusion SARS-CoV-2 spike protein (S-2P) adjuvanted with CpG 1018 and aluminum hydroxide. Here we used the Delta variant to challenge hamsters innoculated with S-2P based on the ancestral strain or the Beta variant in two-dose or three-dose regimens. Two doses of ancestral S-2P followed by the third dose of Beta variant S-2P was shown to induce the highest neutralizing antibody titer against live SARS-CoV-2 of the ancestral strain as well as all VoCs. All regimens of vaccination were able to protect hamsters from SARS-CoV-2 Delta variant challenge and reduce lung live virus titer. Three doses of vaccination significantly reduced lung viral RNA titer, regardless of using the ancestral or Beta variant S-2P as the third dose. Based on the immunogenicity and viral challenge data, two doses of ancestral S-2P followed by the third dose of Beta variant S-2P could induce broad and potent immune response against the variants.

scholarly journals Effect of a booster-dose of rabies vaccine on the duration of virus neutralizing antibody titers in bovines

1998 ◽  
Vol 31 (4) ◽  
pp. 367-371 ◽  
Author(s):  
Avelino Albas ◽  
Paulo Eduardo Pardo ◽  
Albério Antonio Barros Gomes ◽  
Fernanda Bernardi ◽  
Fumio Honma Ito
Keyword(s):  
Immune Response ◽  
Neutralizing Antibodies ◽  
Booster Dose ◽  
Neutralization Test ◽  
Neutralizing Antibody ◽  
Rabies Vaccine ◽  
Western Region ◽  
Humoral Immune ◽  
Paulo State ◽  
Antibody Titers

Humoral immune response using inactivated rabies vaccine was studied in 35 nelore cross-bred bovines of western region of São Paulo state. Ninety days after vaccination, 13 (92.8%) animals presented titers 30.5IU/ml, through mouse neutralization test. After 180 days, 9 (64.3%) sera showed titers 30.5IU/ml, after 270 days, only one (7.1%) showed a titer of 0.51IU/ml, and after 360 days, all animals showed titers < 0.5IU/ml. Group of animals receiving booster dose 30 days after vaccination presented, two months after, all with titers > 0.5IU/ml. At 180 days, 17 (80.9%) sera presented titers > 0.5IU/ml; at 270 days, 15 (71.4%), with titers 30.5IU/ml and at 360 days, 4 (19.0%), with titers 30.5IU/ml. Booster-dose ensured high levels of neutralizing antibodies for at least three months, and 240 days after revaccination, 71.4% of animals were found with titers 30.5IU/ml.

Comparison of Injected and Oral Polio Vaccine for Booster Immunization During the 1979 Polio Outbreak in Lancaster County, Pennsylvania

1981 ◽  
Vol 2 (5) ◽  
pp. 377-379
Author(s):  
Robert G. Doe ◽  
Bruce Kleger ◽  
John L. Randall
Keyword(s):  
Booster Vaccination ◽  
Oral Polio Vaccine ◽  
Neutralizing Antibody ◽  
Igg Antibody ◽  
Booster Immunization ◽  
Lancaster County ◽  
Polio Vaccine ◽  
Before And After ◽  
Antibody Titers ◽  
Better Than

AbstractDuring a 1979 outbreak of poliomyelitis in Lancaster County, Pennsylvania, we investigated the neccessity for and the response to booster vaccination of hospital personnel. The immune response of hospital employees who received booster injections of Salk vaccine (n=38) was compared with that of residents in the surrounding community who received Sabin trivalent OPV boosters (n=43). Serum neutralizing antibody titers to the three polio serotypes were measured before and after booster immunization. Results indicated that 38% of the subjects in both groups had low initial antibody titers. Salk vaccine was in all circumstances as effective or better than Sabin vaccine in increasing neutralizing IgG antibody titers [Infect Control 1981; 2(5):377-379.]

scholarly journals Recombinant protein subunit SARS-CoV-2 vaccines formulated with CoVaccine HT adjuvant induce broad, Th1 biased, humoral and cellular immune responses in mice

2021 ◽  
Author(s):  
Chih-Yun Lai ◽  
Albert To ◽  
Teri Ann S. Wong ◽  
Michael M. Lieberman ◽  
David E. Clements ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Herd Immunity ◽  
Neutralizing Antibody ◽  
Protein Subunit ◽  
Cellular Immune Responses ◽  
Oil In Water ◽  
History Of ◽  
Antibody Titers ◽  
Outbred Mice ◽  
Cellular Immune

ABSTRACTThe speed at which several COVID-19 vaccines went from conception to receiving FDA and EMA approval for emergency use is an achievement unrivaled in the history of vaccine development. Mass vaccination efforts using the highly effective vaccines are currently underway to generate sufficient herd immunity and reduce transmission of the SARS-CoV-2 virus. Despite the most advanced vaccine technology, global recipient coverage, especially in resource-poor areas remains a challenge as genetic drift in naïve population pockets threatens overall vaccine efficacy. In this study, we described the production of insect-cell expressed SARS-CoV-2 spike protein ectodomain and examined its immunogenicity in mice. We demonstrated that, when formulated with CoVaccine HT™adjuvant, an oil-in-water nanoemulsion compatible with lyophilization, our vaccine candidates elicit a broad-spectrum IgG response, high neutralizing antibody titers, and a robust, antigen-specific IFN-γ secreting response from immune splenocytes in outbred mice. Our findings lay the foundation for the development of a dry-thermostabilized vaccine that is deployable without refrigeration.

scholarly journals Single-dose SARS-CoV-2 vaccine in a prospective cohort of COVID-19 patients

2021 ◽  
Author(s):  
Marit J. van Gils ◽  
Hugo D.G. Willegen ◽  
Elke Wynberg ◽  
Alvin X. Han ◽  
Karlijn van der Straten ◽  
...  
Keyword(s):  
Single Dose ◽  
Prospective Cohort ◽  
Serum Antibody ◽  
Neutralizing Antibody ◽  
Credible Interval ◽  
Time Interval ◽  
Vaccine Response ◽  
Vaccine Strategy ◽  
Igg Antibody ◽  
Antibody Titers

Background The urgent need for, but limited availability of, SARS-CoV-2 vaccines worldwide has led to widespread consideration of dose sparing strategies, particularly single vaccine dosing of individuals with prior SARS-CoV-2 infection. Methods We evaluated SARS-CoV-2 specific antibody responses following a single-dose of BNT162b2 (Pfizer-BioNTech) mRNA vaccine in 155 previously SARS-CoV-2-infected individuals participating in a population-based prospective cohort study of COVID-19 patients. Participants varied widely in age, comorbidities, COVID-19 severity and time since infection, ranging from 1 to 15 months. Serum antibody titers were determined at time of vaccination and one week after vaccination. Responses were compared to those in SARS-CoV-2-naive health care workers after two BNT162b2 mRNA vaccine doses. Results Within one week of vaccination, IgG antibody levels to virus spike and RBD proteins increased 27 to 29-fold and neutralizing antibody titers increased 12-fold, exceeding titers of fully vaccinated SARS-CoV-2-naive controls (95% credible interval (CrI): 0.56 to 0.67 v. control 95% CrI: -0.16 to -0.02). Pre-vaccination neutralizing antibody titers had the largest positive mean effect size on titers following vaccination (95% CrI (0.16 to 0.45)). COVID-19 severity, the presence of comorbidities and the time interval between infection and vaccination had no discernible impact on vaccine response. Conclusion A single dose of BNT162b2 mRNA vaccine up to 15 months after SARS-CoV-2 infection provides neutralizing titers exceeding two vaccine doses in previously uninfected individuals. These findings support wide implementation of a single-dose mRNA vaccine strategy after prior SARS-CoV-2 infection.

scholarly journals A single immunization with spike-functionalized ferritin vaccines elicits neutralizing antibody responses against SARS-CoV-2 in mice

2020 ◽  
Author(s):  
Abigail E. Powell ◽  
Kaiming Zhang ◽  
Mrinmoy Sanyal ◽  
Shaogeng Tang ◽  
Payton A. Weidenbacher ◽  
...  
Keyword(s):  
Single Dose ◽  
Neutralizing Antibodies ◽  
Subunit Vaccine ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Receptor Binding Domain ◽  
Amino Acid Deletion ◽  
Vaccine Candidates ◽  
Self Assembling ◽  
Antibody Titers

AbstractDevelopment of a safe and effective SARS-CoV-2 vaccine is a public health priority. We designed subunit vaccine candidates using self-assembling ferritin nanoparticles displaying one of two multimerized SARS-CoV-2 spikes: full-length ectodomain (S-Fer) or a C-terminal 70 amino-acid deletion (SΔC-Fer). Ferritin is an attractive nanoparticle platform for production of vaccines and ferritin-based vaccines have been investigated in humans in two separate clinical trials. We confirmed proper folding and antigenicity of spike on the surface of ferritin by cryo-EM and binding to conformation-specific monoclonal antibodies. After a single immunization of mice with either of the two spike ferritin particles, a lentiviral SARS-CoV-2 pseudovirus assay revealed mean neutralizing antibody titers at least 2-fold greater than those in convalescent plasma from COVID-19 patients. Additionally, a single dose of SΔC-Fer elicited significantly higher neutralizing responses as compared to immunization with the spike receptor binding domain (RBD) monomer or spike ectodomain trimer alone. After a second dose, mice immunized with SΔC-Fer exhibited higher neutralizing titers than all other groups. Taken together, these results demonstrate that multivalent presentation of SARS-CoV-2 spike on ferritin can notably enhance elicitation of neutralizing antibodies, thus constituting a viable strategy for single-dose vaccination against COVID-19.

scholarly journals SARS-CoV-2 Vaccine-Induced Antibody Response and Reinfection in Persons with Past Natural Infection

2021 ◽  
Author(s):  
Nitu Chauhan ◽  
Ajeet Singh Chahar ◽  
Prem Singh ◽  
Neel Sarovar Bhavesh ◽  
Ravi Tandon ◽  
...  
Keyword(s):  
Viral Vector ◽  
Natural Infection ◽  
Previous History ◽  
Adenovirus Vector ◽  
Prior History ◽  
Igg Antibody ◽  
Vector Vaccine ◽  
Women Subjects ◽  
History Of ◽  
Antibody Titers

Several studies have shown that subjects with a history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection had significantly higher antibody titers than previously uninfected vaccinees after vaccination with mRNA vaccine. Yet no information is available for other vaccines. In the current observational cohort study, 105 health care workers who had received Covishield an Adeno associated viral vector-based DNA vaccine were enrolled at Sarojini Nadu Medical College Agra, India. The study included 40 (23 men and 17 women) subjects with a previous history of SARS-CoV-2 infection and 65 participants (39 men and 26 women) who were not infected previously. Both the groups received the adenovirus vector vaccine ChAdOx1-S recombinant vaccines (Covishield, Astra Zeneca). The levels of SARS-CoV-2-anti-spike-IgG-antibodies titer were measured using Electrochemiluminescence immunoassay on Roche platform as arbitrary units per milliliter (AU/ml). After 28 days of the second dose, subjects with no previous SARSCoV-2 infection showed a significantly lower level of circulating anti-spike-IgG-antibody titers compared to previously infected participants. After the second dose, we also observed a significant increase in SARS-CoV-2 infection in subjects with no prior history of SARS-CoV-2 infection compared to subjects with a previous history of natural infection. The most important observation of the study is a low percentage of infection in previously infected subjects. The finding of the study also indicates the presence of robust humoral memory response in previously infected patients.

scholarly journals Purification, Stability, and Immunogenicity Analyses of Five Bluetongue Virus Proteins for Use in Development of a Subunit Vaccine That Allows Differentiation of Infected from Vaccinated Animals

2014 ◽  
Vol 21 (3) ◽  
pp. 443-452 ◽  
Author(s):  
Jenna Anderson ◽  
Emmanuel Bréard ◽  
Karin Lövgren Bengtsson ◽  
Kjell-Olov Grönvik ◽  
Stéphan Zientara ◽  
...  
Keyword(s):  
Bluetongue Virus ◽  
Subunit Vaccine ◽  
Clinical Signs ◽  
Igg Antibody ◽  
Content Type ◽  
Vector Borne Diseases ◽  
Antibody Titers ◽  
A Subunit ◽  
Bluetongue Disease ◽  
Vector Borne

ABSTRACTBluetongue virus (BTV) causes bluetongue disease, a vector-borne disease of ruminants. The recent northerly spread of BTV serotype 8 in Europe resulted in outbreaks characterized by clinical signs in cattle, including unusual teratogenic effects. Vaccination has been shown to be crucial for controlling the spread of vector-borne diseases such as BTV. With the aim of developing a novel subunit vaccine targeting BTV-8 that allows differentiation of infected from vaccinated animals, five His-tagged recombinant proteins, VP2 and VP5 of BTV-8 and NS1, NS2, and NS3 of BTV-2, were expressed in baculovirus orEscherichia coliexpression systems for further study. Optimized purification protocols were determined for VP2, NS1, NS2, and NS3, which remained stable for detection for at least 560 to 610 days of storage at +4°C or −80°C, and Western blotting using sera from vaccinated or experimentally infected cattle indicated that VP2 and NS2 were recognized by BTV-specific antibodies. To characterize murine immune responses to the four proteins, mice were subcutaneously immunized twice at a 4-week interval with one of three protein combinations plus immunostimulating complex ISCOM-Matrix adjuvant or with ISCOM-Matrix alone (n= 6 per group). Significantly higher serum IgG antibody titers specific for VP2 and NS2 were detected in immunized mice than were detected in controls. VP2, NS1, and NS2 but not NS3 induced specific lymphocyte proliferative responses upon restimulation of spleen cells from immunized mice. The data suggest that these recombinant purified proteins, VP2, NS1, and NS2, could be an important part of a novel vaccine design against BTV-8.

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