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1.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-337737

ABSTRACT

The COVID-19 pandemic caused by SARS-CoV-2 has caused millions of infections and deaths worldwide. Limited treatment options and the threat from emerging variants underline the need for novel and widely accessible therapeutics. G-quadruplexes (G4s) are nucleic acid secondary structures known to affect many cellular processes including viral replication and transcription. We identified heretofore not reported G4s with remarkably low mutation frequency across >4 million SARS-CoV-2 genomes. The G4 structure was targeted using FDA approved drugs that can bind G4s - Chlorpromazine (CPZ) and Prochlorperazine (PCZ). We found significant inhibition in lung pathology and lung viral load of SARS-CoV-2 challenged hamsters when treated with CPZ, PCZ that was comparable to the widely used antiviral drug Remdesivir. In support, in vitro G4 binding, inhibition of reverse transcription from RNA isolated from COVID-infected humans, and attenuated viral replication and infectivity in vero cell cultures were clear in case of both CPZ/PCZ. Apart from the wide accessibility of CPZ/PCZ, targeting relatively invariant nucleic acid structures poses an attractive strategy against fast mutating viruses like SARS-CoV-2.

2.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-336754

ABSTRACT

ABSTRACT Background After establishing safety and immunogenicity of Biological E’s CORBEVAX™ vaccine in adult population (18-80 years) in Phase 1-3 studies, vaccine is further tested in children and adolescents in this study. Methods This is a phase-2/3 prospective, randomised, double-blind, placebo controlled, study evaluating safety, reactogenicity, tolerability and immunogenicity of CORBEVAX™ vaccine in children and adolescents of either gender between <18 to ≥12 years of age in Phase-II and <18 to ≥5 years of age in Phase-III with placebo as a control. This study has two age sub groups;age subgroup-1 with subjects <18 to ≥12 years of age and age subgroup-2 with subjects <12 to ≥5 years of age. In both age sub groups eligible subjects (SARS-CoV-2 RT-PCR negative and seronegative at baseline) were randomized to receive either CORBEVAX™ vaccine or Placebo in 3: 1 ratio. Findings The safety profile of CORBEVAX™ vaccine in both pediatric cohorts was comparable to the placebo control group. Majority of reported adverse events (AEs) were mild in nature. No severe or serious AEs, medically attended AEs (MAAEs) or AEs of special interest (AESI) were reported during the study period and all the reported AEs resolved without any sequelae. In both pediatric age groups, CORBEVAX™ vaccinated subjects showed significant improvement in humoral immune-responses in terms of anti-RBD-IgG concentrations, anti-RBD-IgG1 titers, neutralizing antibody (nAb)-titers against Ancestral Wuhan and Delta strains. Significantly high interferon gamma immune response (cellular) was elicited by CORBEVAX™ vaccinated subjects with minimal effect on IL-4 cytokine secretion. Interpretations The safety profile of CORBEVAX™ vaccine in <18 to ≥5 years’ children and adolescents was found to be safe and tolerable. The adverse event profile was also found to be acceptable. Significant increase in anti-RBD IgG and nAb titers and IFN-gamma immune responses were observed post vaccination in both pediatric age sub groups. Both humoral and cellular immune responses were found to be non-inferior to the immune responses induced by CORBEVAX™ vaccine in adult population. This study shows that CORBEVAX™ vaccine is highly immunogenic and can be safely administered to pediatric population as young as 5 years old. The study was prospectively registered with clinical trial registry of India-CTRI/2021/10/037066

3.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-335446

ABSTRACT

Pathogenic infections cause thymic atrophy, perturb thymic-T cell development and alter immunological response. Previous studies reported dysregulated T cell function and lymphopenia in coronavirus disease-19 (COVID-19) patients. However, immune-pathological changes, in the thymus, post severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection have not been elucidated. Here, we report SARS-CoV-2 infects thymocytes, depletes CD4 + CD8+ (double positive;DP) T cell population associated with an increased apoptosis of thymocytes, which leads to severe thymic atrophy in K18-hACE2-Tg mice. CD44 + CD25- T cells were found to be enriched in infected thymus, indicating an early arrest in the T cell developmental pathway. Further, Interferon gamma (IFN-γ) was crucial for thymic atrophy, as anti-IFN-g antibody neutralization rescued the loss of thymic involution. Therapeutic use of remdesivir (prototype anti-viral drug) was also able to rescue thymic atrophy. While Omicron variant of SARS-CoV2 caused marginal thymic atrophy, delta variant of SARS-CoV-2 exhibited most profound thymic atrophy characterized by severely depleted DP T cells. Recently characterized broadly SARS-CoV-2 neutralizing monoclonal antibody P4A2 was able to rescue thymic atrophy and restore thymic developmental pathway of T cells. Together, we provide the first report of SARS-CoV-2 associated thymic atrophy resulting from impaired T cell developmental pathway and also explains dysregulated T cell function in COVID-19.

4.
PLoS Pathog ; 18(4): e1010465, 2022 04.
Article in English | MEDLINE | ID: covidwho-1817511

ABSTRACT

Although efficacious vaccines have significantly reduced the morbidity and mortality of COVID-19, there remains an unmet medical need for treatment options, which monoclonal antibodies (mAbs) can potentially fill. This unmet need is exacerbated by the emergence and spread of SARS-CoV-2 variants of concern (VOCs) that have shown some resistance to vaccine responses. Here we report the isolation of five neutralizing mAbs from an Indian convalescent donor, out of which two (THSC20.HVTR04 and THSC20.HVTR26) showed potent neutralization of SARS-CoV-2 VOCs at picomolar concentrations, including the Delta variant (B.1.617.2). One of these (THSC20.HVTR26) also retained activity against the Omicron variant. These two mAbs target non-overlapping epitopes on the receptor-binding domain (RBD) of the spike protein and prevent virus attachment to its host receptor, human angiotensin converting enzyme-2 (hACE2). Furthermore, the mAb cocktail demonstrated protection against the Delta variant at low antibody doses when passively administered in the K18 hACE2 transgenic mice model, highlighting their potential as a cocktail for prophylactic and therapeutic applications. Developing the capacity to rapidly discover and develop mAbs effective against highly transmissible pathogens like coronaviruses at a local level, especially in a low- and middle-income country (LMIC) such as India, will enable prompt responses to future pandemics as an important component of global pandemic preparedness.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Antibodies, Monoclonal , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/prevention & control , Mice , Spike Glycoprotein, Coronavirus
5.
Int J Biol Macromol ; 209(Pt A): 1359-1367, 2022 Jun 01.
Article in English | MEDLINE | ID: covidwho-1800033

ABSTRACT

The COVID-19 pandemic caused by SARS-CoV-2 has a significant burden on the economy and healthcare around the world. Vaccines are the most effective tools to fight infectious diseases by containing the spread of the disease. The current vaccines against SARS-CoV-2 are mostly based on the spike protein of SARS-CoV-2, which is large and has many immune-dominant non-neutralizing epitopes that may effectively skew the antibody response towards non-neutralizing antibodies. Here, we have explored the possibility of immune-focusing the receptor binding motif (RBM) of the spike protein of SARS-CoV-2 that induces mostly neutralizing antibodies in natural infection or in vacinees. The result shows that the scaffolded RBM can bind to Angiotensin Converting Enzyme 2 (ACE2) although with low affinity and induces a strong antibody response in mice. The immunized sera can bind both, the receptor binding domain (RBD) and the spike protein, which holds the RBM in its natural context. Sera from the immunized mice showed robust interferon γ response but poor neutralization of SARS-CoV-2 suggesting presence of a predominant T cell epitope on scaffolded RBM. Together, we provide a strategy for inducing strong antigenic T cell response which could be exploited further for future vaccine designing and development against SARS-CoV-2 infection.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/prevention & control , COVID-19 Vaccines , Epitopes , Humans , Mice , Pandemics/prevention & control , Protein Binding , Spike Glycoprotein, Coronavirus/chemistry
6.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-333046

ABSTRACT

Pathogenic infections cause thymic atrophy, perturb thymic-T cell development and alter immunological response. Previous studies reported dysregulated T cell function and lymphopenia in coronavirus disease-19 (COVID-19) patients. However, immune-pathological changes, in the thymus, post severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection have not been elucidated. Here, we report SARS-CoV-2 infects thymocytes, depletes CD4+CD8+ (double positive;DP) T cell population associated with an increased apoptosis of thymocytes, which leads to severe thymic atrophy in K18-hACE2-Tg mice. CD44+CD25-T cells were found to be enriched in infected thymus, indicating an early arrest in the T cell developmental pathway. Further, Interferon gamma (IFN-γ) was crucial for thymic atrophy, as anti-IFN-γ antibody neutralization rescued the loss of thymic involution. Therapeutic use of remdesivir (prototype anti-viral drug) was also able to rescue thymic atrophy. While Omicron variant of SARS-CoV2 caused marginal thymic atrophy, delta variant of SARS-CoV-2 exhibited most profound thymic atrophy characterized by severely depleted DP T cells. Recently characterized broadly SARS-CoV-2 neutralizing monoclonal antibody P4A2 was able to rescue thymic atrophy and restore thymic developmental pathway of T cells. Together, we provide the first report of SARS-CoV-2 associated thymic atrophy resulting from impaired T cell developmental pathway and also explains dysregulated T cell function in COVID-19.

7.
Lancet Infect Dis ; 22(4): 473-482, 2022 04.
Article in English | MEDLINE | ID: covidwho-1757985

ABSTRACT

BACKGROUND: SARS-CoV-2 variants of concern (VOCs) have threatened COVID-19 vaccine effectiveness. We aimed to assess the effectiveness of the ChAdOx1 nCoV-19 vaccine, predominantly against the delta (B.1.617.2) variant, in addition to the cellular immune response to vaccination. METHODS: We did a test-negative, case-control study at two medical research centres in Faridabad, India. All individuals who had a positive RT-PCR test for SARS-CoV-2 infection between April 1, 2021, and May 31, 2021, were included as cases and individuals who had a negative RT-PCR test were included as controls after matching with cases on calendar week of RT-PCR test. The primary outcome was effectiveness of complete vaccination with the ChAdOx1 nCoV-19 vaccine against laboratory-confirmed SARS-CoV-2 infection. The secondary outcomes were effectiveness of a single dose against SARS-CoV-2 infection and effectiveness of a single dose and complete vaccination against moderate-to-severe disease among infected individuals. Additionally, we tested in-vitro live-virus neutralisation and T-cell immune responses to the spike protein of the wild-type SARS-CoV-2 and VOCs among healthy (anti-nucleocapsid antibody negative) recipients of the ChAdOx1 nCoV-19 vaccine. FINDINGS: Of 2379 cases of confirmed SARS-CoV-2 infection, 85 (3·6%) were fully vaccinated compared with 168 (8·5%) of 1981 controls (adjusted OR [aOR] 0·37 [95% CI 0·28-0·48]), giving a vaccine effectiveness against SARS-CoV-2 infection of 63·1% (95% CI 51·5-72·1). 157 (6·4%) of 2451 of cases and 181 (9·1%) of 1994) controls had received a single dose of the ChAdOx1 nCoV-19 vaccine (aOR 0·54 [95% CI 0·42-0·68]), thus vaccine effectiveness of a single dose against SARS-CoV-2 infection was 46·2% (95% CI 31·6-57·7). One of 84 cases with moderate-to-severe COVID-19 was fully vaccinated compared with 84 of 2295 cases with mild COVID-19 (aOR 0·19 [95% CI 0·01-0·90]), giving a vaccine effectiveness of complete vaccination against moderate-to-severe disease of 81·5% (95% CI 9·9-99·0). The effectiveness of a single dose against moderate-to-severe disease was 79·2% (95% CI 46·1-94·0); four of 87 individuals with moderate-to-severe COVID-19 had received a single dose compared with 153 of 2364 participants with mild disease (aOR 0·20 [95% CI 0·06-0·54]). Among 49 healthy, fully vaccinated individuals, neutralising antibody responses were lower against the alpha (B.1.1.7; geometric mean titre 244·7 [95% CI 151·8-394·4]), beta (B.1.351; 97·6 [61·2-155·8]), kappa (B.1.617.1; 112·8 [72·7-175·0]), and delta (88·4 [61·2-127·8]) variants than against wild-type SARS-CoV-2 (599·4 [376·9-953·2]). However, the antigen-specific CD4 and CD8 T-cell responses were conserved against both the delta variant and wild-type SARS-CoV-2. INTERPRETATION: The ChAdOx1 nCoV-19 vaccine remained effective against moderate-to-severe COVID-19, even during a surge that was dominated by the highly transmissible delta variant of SARS-CoV-2. Spike-specific T-cell responses were maintained against the delta variant. Such cellular immune protection might compensate for waning humoral immunity. FUNDING: Department of Biotechnology India, Council of Scientific and Industrial Research India, and Fondation Botnar.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibody Formation , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines , Case-Control Studies , Humans , Vaccination
9.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-330210

ABSTRACT

The emergence of new variants of SARS-CoV-2 necessitates unremitting efforts to discover novel therapeutic mAbs. Here, we report an extremely potent mAb named P4A2 that can neutralize all the circulating variants of concerns (VOCs) with high efficiency, including the highly transmissible Omicron. The crystal structure of the P4A2 Fab:RBD complex revealed that the residues of the RBD that interact with P4A2 are part of the ACE2-receptor-binding motif and are not mutated in any of the VOCs. The pan coronavirus pseudotyped neutralization assay confirmed that the P4A2 mAb is specific for SARS-CoV-2 and its VOCs. Passive administration of P4A2 to K18-hACE2 transgenic mice conferred protection, both prophylactically and therapeutically, against challenge with VOCs. Overall, our data shows that, the P4A2 mAb has immense therapeutic potential to neutralize the current circulating VOCs and will be highly effective against future variants as well due to its unique mode of binding.

10.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-330074

ABSTRACT

The underlying factors contributing to the evolution of SARS-CoV-2-specific T cell response during COVID-19 infection remain unidentified. To address this, we characterized innate and adaptive immune responses with metabolomic profiling longitudinally at three different time points (0-4, 7-9, and 14-16 days post-COVID-19 positivity) from young mildly symptomatic active COVID-19 patients who got infected with ancestral virus. We observed the induction of anti-RBD and SARS-CoV-2 neutralizing antibodies together with antigen-specific T cell responses as early as 0-4 days post-infection. T cell responses were largely preserved against the delta and omicron variants as compared to the ancestral strain. We determined innate immune responses at an early (days 0-4 post-COVID-19 positivity) time point of active infection in response to TLR 3/7/8 mediated activation. Interestingly, the innate immune response exhibited by the elevated levels of IL-6, IL-1β, and IL-23 correlated with a robust SARS-CoV-2-specific Th1 response at the later time point (14-16 days post covid positivity). To further understand the association of metabolic pathways induced upon active COVID-19 infection with innate and T cell response, metabolomic profiling was performed. As compared to healthy individuals, COVID-19 patients displayed a distinct metabolic signature with an enrichment of pyroglutamate, itaconate, and azelaic acid, which correlated with the SARS-CoV-2-induced innate and T cells response. Our observations reveal mechanisms and potential interventional approaches that may assist in COVID-19 therapeutics and vaccine adjuvant strategies. One Sentence Summary T cell Immune response against SARS-CoV-2 is driven by a proinflammatory innate immune response and an associated metabolic signature in young adults.

11.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-328766

ABSTRACT

SARS-CoV-2 variants acquire mutations to survive within the host and evade immunity. In addition to harboring D614G mutation in spike domain, P681R/H mutation at the junction of the S1/S2 furin cleavage site, is found to be the key mutation in variants of concerns (VoC);Alpha, Delta, and Omicron (B.1.1.519). The impact of these acquired mutations on entry, transmissibility, and infectivity of SARS-CoV2 VoC is not clearly identified. Here, using the spike-based pseudovirus, Delta and D614G+P681R synthetic mutants showed a significant increase in the pseudovirus entry, fusion, and infectivity. In contrast, Omicron spike-based pseudovirus and a synthetic P681H mutant showed preferential hACE2-mediated virus entry over TMPRSS2, less fusion, and highly susceptible to Cathepsin L inhibitor. Taken together, these results indicate while the Delta variant utilizes both ACE2 and TMPRSS2 mediated entry, thus causing systemic infection;Omicron has favored growth in ACE2 expressed cells thus mainly replicating in the upper respiratory tract.

13.
Front Pharmacol ; 12: 746729, 2021.
Article in English | MEDLINE | ID: covidwho-1497115

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection initiates with viral entry in the upper respiratory tract, leading to coronavirus disease 2019 (COVID-19). Severe COVID-19 is characterized by pulmonary pathologies associated with respiratory failure. Thus, therapeutics aimed at inhibiting the entry of the virus or its internalization in the upper respiratory tract are of interest. Herein, we report the prophylactic application of two intranasal formulations provided by the National Medicinal Plant Board (NMPB), Anu oil and til tailya, in the hamster model of SARS-CoV-2 infection. Prophylactic intra-nasal instillation of these oil formulations exhibited reduced viral load in lungs and resulted in reduced body weight loss and lung-pneumonitis. In line with reduced viral load, histopathological analysis revealed a reduction in lung pathology in the Anu oil group as compared to the control infected group. However, the til tailya group did not show a significant reduction in lung pathology. Furthermore, molecular analysis using mRNA expression profiling indicated reduced expression of pro-inflammatory cytokine genes, including Th1 and Th17 cytokines for both the intranasal formulations as a result of decreased viral load. Together, the prophylactic intranasal application of Anu oil seems to be useful in limiting both viral load and severity in SARS-CoV2 infection in the hamster model.

15.
Front Immunol ; 12: 641447, 2021.
Article in English | MEDLINE | ID: covidwho-1264330

ABSTRACT

The newly emerged novel coronavirus, SARS-CoV-2, the causative agent of COVID-19 has proven to be a threat to the human race globally, thus, vaccine development against SARS-CoV-2 is an unmet need driving mass vaccination efforts. The receptor binding domain of the spike protein of this coronavirus has multiple neutralizing epitopes and is associated with viral entry. Here we have designed and characterized the SARS-CoV-2 spike protein fragment 330-526 as receptor binding domain 330-526 (RBD330-526) with two native glycosylation sites (N331 and N343); as a potential subunit vaccine candidate. We initially characterized RBD330-526 biochemically and investigated its thermal stability, humoral and T cell immune response of various RBD protein formulations (with or without adjuvant) to evaluate the inherent immunogenicity and immunomodulatory effect. Our result showed that the purified RBD immunogen is stable up to 72 h, without any apparent loss in affinity or specificity of interaction with the ACE2 receptor. Upon immunization in mice, RBD generates a high titer humoral response, elevated IFN-γ producing CD4+ cells, cytotoxic T cells, and robust neutralizing antibodies against live SARS-CoV-2 virus. Our results collectively support the potential of RBD330-526 as a promising vaccine candidate against SARS-CoV-2.


Subject(s)
Antibodies, Viral/blood , COVID-19 Vaccines/administration & dosage , Immunity, Humoral/drug effects , Immunogenicity, Vaccine , Peptide Fragments/administration & dosage , Spike Glycoprotein, Coronavirus/administration & dosage , Th1 Cells/drug effects , Adjuvants, Immunologic/administration & dosage , Animals , Biomarkers/blood , COVID-19 Vaccines/immunology , Chlorocebus aethiops , Drug Stability , Glycosylation , HEK293 Cells , Humans , Immunization , Interferon-gamma/blood , Male , Mice, Inbred C57BL , Peptide Fragments/immunology , Protein Interaction Domains and Motifs , Protein Stability , Spike Glycoprotein, Coronavirus/immunology , Th1 Cells/immunology , Th1 Cells/metabolism , Vaccines, Subunit/administration & dosage , Vaccines, Subunit/immunology , Vero Cells
16.
Microbes Infect ; 23(4-5): 104843, 2021.
Article in English | MEDLINE | ID: covidwho-1258465

ABSTRACT

COVID-19 pandemic has caused severe disruption of global health and devastated the socio-economic conditions all over the world. The disease is caused by SARS-CoV-2 virus that belongs to the family of Coronaviruses which are known to cause a wide spectrum of diseases both in humans and animals. One of the characteristic features of the SARS-CoV-2 virus is the high reproductive rate (R0) that results in high transmissibility of the virus among humans. Vaccines are the best option to prevent and control this disease. Though, the traditional intramuscular (IM) route of vaccine administration is one of the effective methods for induction of antibody response, a needle-free self-administrative intradermal (ID) immunization will be easier for SARS-CoV-2 infection containment, as vaccine administration method will limit human contacts. Here, we have assessed the humoral and cellular responses of a RBD-based peptide immunogen when administered intradermally in BALB/c mice and side-by-side compared with the intramuscular immunization route. The results demonstrate that ID vaccination is well tolerated and triggered a significant magnitude of humoral antibody responses as similar to IM vaccination. Additionally, the ID immunization resulted in higher production of IFN-γ and IL-2 suggesting superior cellular response as compared to IM route. Overall, our data indicates immunization through ID route provides a promising alternative approach for the development of self-administrative SARS-CoV-2 vaccine candidates.


Subject(s)
COVID-19 Vaccines/administration & dosage , COVID-19/prevention & control , Vaccination/methods , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Antibody Formation , Female , Immunity, Cellular , Immunity, Humoral , Injections, Intradermal , Injections, Intramuscular , Male , Mice, Inbred BALB C , Spike Glycoprotein, Coronavirus/immunology
17.
Front Immunol ; 12: 613045, 2021.
Article in English | MEDLINE | ID: covidwho-1177974

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) initiates infection by attachment of the surface-exposed spike glycoprotein to the host cell receptors. The spike glycoprotein (S) is a promising target for inducing immune responses and providing protection; thus the ongoing efforts for the SARS-CoV-2 vaccine and therapeutic developments are mostly spiraling around S glycoprotein. The matured functional spike glycoprotein is presented on the virion surface as trimers, which contain two subunits, such as S1 (virus attachment) and S2 (virus fusion). The S1 subunit harbors the N-terminal domain (NTD) and the receptor-binding domain (RBD). The RBD is responsible for binding to host-cellular receptor angiotensin-converting enzyme 2 (ACE2). The NTD and RBD of S1, and the S2 of S glycoprotein are the major structural moieties to design and develop spike-based vaccine candidates and therapeutics. Here, we have identified three novel epitopes (20-amino acid peptides) in the regions NTD, RBD, and S2 domains, respectively, by structural and immunoinformatic analysis. We have shown as a proof of principle in the murine model, the potential role of these novel epitopes in-inducing humoral and cellular immune responses. Further analysis has shown that RBD and S2 directed epitopes were able to efficiently inhibit the replication of SARS-CoV-2 wild-type virus in vitro suggesting their role as virus entry inhibitors. Structural analysis revealed that S2-epitope is a part of the heptad repeat 2 (HR2) domain which might have plausible inhibitory effects on virus fusion. Taken together, this study discovered novel epitopes that might have important implications in the development of potential SARS-CoV-2 spike-based vaccine and therapeutics.


Subject(s)
Epitopes/immunology , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/immunology , Virus Replication/immunology , Animals , COVID-19 Vaccines/immunology , Female , Humans , Mice , Mice, Inbred BALB C , Protein Domains , Virus Internalization
18.
iScience ; 24(4): 102298, 2021 Apr 23.
Article in English | MEDLINE | ID: covidwho-1126886

ABSTRACT

We report the development and evaluation of safety and immunogenicity of a whole virion inactivated (WVI) SARS-CoV-2 vaccine (BBV152), adjuvanted with aluminum hydroxide gel (Algel), or TLR7/8 agonist chemisorbed Algel. We used a well-characterized SARS-CoV-2 strain and an established Vero cell platform to produce large-scale GMP-grade highly purified inactivated antigen. Product development and manufacturing process were carried out in a BSL-3 facility. Immunogenicity and safety were determined at two antigen concentrations (3µg and 6µg), with two different adjuvants, in mice, rats, and rabbits. Our results show that BBV152 vaccine formulations generated significantly high antigen-binding and neutralizing antibody titers (NAb), at both concentrations, in all three species with excellent safety profiles. The inactivated vaccine formulation contains TLR7/8 agonist adjuvant-induced Th1-biased antibody responses with elevated IgG2a/IgG1 ratio and increased levels of SARS-CoV-2-specific IFN-γ+ CD4+ T lymphocyte response. Our results support further development for phase I/II clinical trials in humans.

19.
Environ Dev Sustain ; 23(6): 8147-8160, 2021.
Article in English | MEDLINE | ID: covidwho-809083

ABSTRACT

The novel coronavirus disease is known as COVID-19, which is declared as a pandemic by the World Health Organization during March 2020. In this study, the COVID-19 connection with various weather parameters like temperature, wind speed, and relative humidity is investigated and the future scenario of COVID-19 is predicted based on the Gaussian model (GM). This study is conducted in Delhi, the capital city of India, during the lowest mobility rate due to strict lockdown nationwide for about two months from March 15 to May 17, 2020. Spearman correlation is applied to obtain the interconnection of COVID-19 cases with weather parameters. Based on statistical analysis, this has been observed that the temperature parameter shows a significant positive trend during the period of study. The number of confirmed cases of COVID-19 is fitted with respect to the number of days by using the Gaussian curve and it is estimated on the basis of the model that maximum cases will go up to 123,886 in number. The maximum number of cases will be observed during the range of 166 ± 36 days. It is also estimated by using the width of the fitted GM that it will take minimum of 10 months for the complete recovery from COVID-19. Additionally, the linear regression technique is used to find the trend of COVID-19 cases with temperature and it is estimated that with an increase in temperature by 1 °C, 30 new COVID-19 cases on daily basis will be expected to observe. This study is believed to be a preliminary study and to better understand the concrete relationship of coronavirus, at least one complete cycle is essential to investigate. The laboratory-based study is essential to be done to support the present field-based study. Henceforth, based on preliminary studies, significant inputs are put forth to the research community and government to formulate thoughtful strategies like medical facilities such as ventilators, beds, testing centers, quarantine centers, etc., to curb the effects of COVID-19.

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