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3.
EBioMedicine ; 79: 103997, 2022 Apr 08.
Article in English | MEDLINE | ID: covidwho-1778096

ABSTRACT

BACKGROUND: SARS-CoV-2 Omicron variant is rampantly spreading across the globe. We assessed the pathogenicity and immune response generated by BA.1.1 sub-lineage of SARS-CoV-2 [Omicron (R346K) variant] in 5 to 6-week old Syrian hamsters and compared the observations with that of Delta variant infection. METHODS: Virus shedding, organ viral load, lung disease and immune response generated in hamsters were sequentially assessed. FINDINGS: The disease characteristics of the Omicron (R346K) variant were found to be similar to that of the Delta variant infection in hamsters like viral replication in the respiratory tract and interstitial pneumonia. The Omicron (R346K) infected hamsters demonstrated lesser body weight reduction and viral RNA load in the throat swab and nasal wash samples in comparison to the Delta variant infection. The viral load in the lungs and nasal turbinate samples and the lung disease severity of the Omicron (R346K) infected hamsters were found comparable with that of the Delta variant infected hamsters. Neutralizing antibody response against Omicron (R346K) variant was detected from day 5 and the cross-neutralization titre of the sera against other variants showed severe reduction ie., 7 fold reduction against Alpha and no titers against B.1, Beta and Delta. INTERPRETATION: This preliminary data shows that Omicron (R346K) variant infection can produce moderate to severe lung disease similar to that of the Delta variant and the neutralizing antibodies produced in response to Omicron (R346K) variant infection shows poor neutralizing ability against other co-circulating SARS-CoV-2 variants like Delta which necessitates caution as it may lead to increased cases of reinfection. FUNDING: This study was supported by Indian Council of Medical Research as an intramural grant (COVID-19) to ICMR-National Institute of Virology, Pune.

4.
J Travel Med ; 2022 Mar 24.
Article in English | MEDLINE | ID: covidwho-1758786

ABSTRACT

The COVID-19 recovered individuals with one or two dose of Sputnik vaccine had relatively higher antibody response in comparison to the naïve individuals received either one or two doses of Sputnik vaccine. The study demonstrated the robust humoral immune response among vaccinees.

5.
J Travel Med ; 2022 Mar 24.
Article in English | MEDLINE | ID: covidwho-1758785

ABSTRACT

The neutralizing antibody responses were significantly elevated after 3rd dose of BBV152/Covaxin against the B.1 (19.11 fold)variant including Delta (16.51 fold), Beta (14.70 fold) and Omicron (18.53 fold) Variants of concern in comparison with two dose vaccine, providing assurance of a protective immune response of booster in recipients.

7.
Viruses ; 14(3)2022 03 13.
Article in English | MEDLINE | ID: covidwho-1742725

ABSTRACT

The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) Delta variant has evolved to become the dominant SARS-CoV-2 lineage with multiple sub-lineages and there are also reports of re-infections caused by this variant. We studied the disease characteristics induced by the Delta AY.1 variant and compared it with the Delta and B.1 variants in Syrian hamsters. We also assessed the potential of re-infection by these variants in Coronavirus disease 2019 recovered hamsters 3 months after initial infection. The variants produced disease characterized by high viral load in the respiratory tract and interstitial pneumonia. The Delta AY.1 variant produced mild disease in the hamster model and did not show any evidence of neutralization resistance due to the presence of the K417N mutation, as speculated. Re-infection with a high virus dose of the Delta and B.1 variants 3 months after B.1 variant infection resulted in reduced virus shedding, disease severity and increased neutralizing antibody levels in the re-infected hamsters. The reduction in viral load and lung disease after re-infection with the Delta AY.1 variant was not marked. Upper respiratory tract viral RNA loads remained similar after re-infection in all the groups. The present findings show that prior infection could not produce sterilizing immunity but that it can broaden the neutralizing response and reduce disease severity in case of reinfection.


Subject(s)
COVID-19 , Reinfection , Animals , Cricetinae , Mesocricetus , SARS-CoV-2/genetics , Severity of Illness Index , Trachea
10.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-324369

ABSTRACT

The COVID-19 pandemic is a global health crisis that has severely affected mankind and posed a great challenge to the public health system of affected countries. The availability of a safe and effective vaccine is the need of the hour to overcome this crisis. Here, we have developed and assessed the protective efficacy and immunogenicity of an inactivated SARS-CoV-2 vaccine (BBV152) in rhesus macaques (Macaca mulata). Twenty macaques were divided into four groups of five animals each. One group was administered a placebo while three groups were immunized with three different vaccine candidates at 0 and 14 days. All the macaques were challenged with SARS-CoV-2 fourteen days after the second dose. The protective response was observed with increasing SARS-CoV-2 specific IgG and neutralizing antibody titers from 3rd-week post-immunization. Viral clearance was observed from bronchoalveolar lavage fluid, nasal swab, throat swab, and lung tissues at 7 days post-infection in the vaccinated groups. No evidence of pneumonia was observed by histopathological examination in vaccinated groups, unlike the placebo group which showed features of interstitial pneumonia and localization of viral antigen in the alveolar epithelium and macrophages by immunohistochemistry. Data from this study substantiate the immunogenicity of the vaccine candidates and BBV152 is being evaluated in Phase I clinical trials in India (NCT04471519).

11.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-320750

ABSTRACT

The pandemic of COVID -19 caused by SARS-CoV-2 is leading to a humongous impact on the mankind with over a million people succumbing to it worldwide. Although there are few drugs approved for the treatment, there is not yet a safe and effective vaccine available for COVID-19. Also, the passive immunization therapy with convalescent plasma, though potentially an effective treatment option for other viral disease has limitation of availability. The prior use of immunoglobulins generated in animals has proven to be effective in several viral and bacterial diseases. Here, we report the development and evaluation of equine hyper immune globulin raised against inactivated SARS-CoV-2 virus. Post immunization neutralization titres of the equines demonstrated high neutralizing antibodies. To minimize the adverse effects, the immunoglobulins were digested with pepsin, and purified to obtain the F(ab’)2 fragments. The average nAb titre of the purified bulk was 22,927 and correlated with high IgG binding efficiency in ELISA. The quality control assessments of the different batches proved to have consistent nAb titres. The study provides evidence of the potential of generating highly purified F(ab’)2 from equines against SARS-CoV-2 that can demonstrate consistent and high neutralization activity. Further, in-vivo testing for efficacy of this indigenously developed, cost effective product will pave the way to clinical evaluation.

12.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-317246

ABSTRACT

The availability of a safe and effective vaccine would be the eventual measure to deal with SARS-CoV-2 threat. Here, we have developed and assessed the immunogenicity and protective efficacy of an inactivated SARS-CoV-2 vaccine (BBV152) in hamsters. Three dose vaccination regime with three formulations of BBV152 induced significant titres of SARS-CoV-2 specific IgG and neutralizing antibodies. The formulation with imidazoquinoline adsorbed on alum adjuvant remarkably generated a quick and robust immune response. Th 1 biased immune response was demonstrated by the detection of IgG2 antibodies. Post-SARS-CoV-2 infection, vaccinated hamsters did not show any histopathological changes in the lungs. The protection of the hamsters was evident by the rapid clearance of the virus from lower respiratory tract, reduced virus load in upper respiratory tract, absence of lung pathology and robust humoral immune response. These findings confirm the immunogenic potential of BBV152 and further protection of hamsters challenged with SARS-CoV-2.

15.
Int J Infect Dis ; 112: 103-110, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1654539

ABSTRACT

OBJECTIVES: Monitoring the antibody responses to SARS-CoV-2 infection and its correlation to clinical spectrum of disease is critical in understanding the disease progression and protection against re-infection. We assessed the nucleocapsid (N) and receptor-binding-domain of spike (SRBD) protein specific IgG and neutralizing antibody (NAb) responses in COVID-19 patients up to 8 months and its correlation with diverse disease spectrum. METHODS: During the first wave of the SARS-CoV-2 pandemic, from 284 COVID-19 patients, 608 samples were collected up to 8 months post infection. The patients were categorized as asymptomatic, symptomatic and severe. The N and SRBD IgG and NAb titers were evaluated and correlated with clinical data. RESULTS: A steep increase in antigen specific antibody titers was observed till 40 days post onset of the disease (POD), followed by a partial decline till 240 days. Severe disease was associated with a stronger SRBD IgG response and higher NAb titers. The persistence of antibody response was observed in 76% against N, 80% against SRBD and 80% for NAbs of cases up to 8 months POD. CONCLUSION: RBD and N protein specific IgG persisted till 240 days POD which correlated with NAb response, irrespective of individual`s symptomatic status indicating overall robust protection against re-infection.


Subject(s)
COVID-19 , Spike Glycoprotein, Coronavirus , Antibodies, Neutralizing , Antibodies, Viral , Humans , Nucleocapsid , SARS-CoV-2
16.
J Travel Med ; 2021 Dec 28.
Article in English | MEDLINE | ID: covidwho-1592815

ABSTRACT

Highlight-. The Delta variant lead to the resurgence of the second wave in India. A 1.51-fold increase in neutralizing antibody response was observed in the second wave compared to first wave, indicating the second wave dominated by the Delta elicited a robust immune response.

17.
J Infect Public Health ; 15(2): 164-171, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1587224

ABSTRACT

BACKGROUND: Considering the potential threat from emerging Severe Acute Respiratory Syndrome-Corona Virus-2 (SARS-CoV-2) variants and the rising COVID-19 cases, SARS-CoV-2 genomic surveillance is ongoing in India. We report herewith the isolation of the P.2 variant (B.1.1.28.2) from international travelers and further its pathogenicity evaluation and comparison with D614G variant (B.1) in hamster model. METHODS: Virus isolation was performed in Vero CCL81 cells and genomic characterization by next generation sequencing. The pathogenicity and host immune response of the isolate was assessed in Syrian hamster model and compared with B.1 variant. RESULTS: B.1.1.28.2 variant was isolated from nasal/throat swabs of international travelers returned to India from United Kingdom and Brazil. The B.1.1.28.2 variant induced body weight loss, viral replication in the respiratory tract and caused severe lung pathology in infected Syrian hamster model in comparison, with B.1 variant infected hamsters. The sera from B.1.1.28.2 infected hamsters efficiently neutralized the D614G variant virus whereas 6-fold reduction in the neutralization was seen in case of D614G variant infected hamsters' sera with the B.1.1.28.2 variant. CONCLUSIONS: B.1.1.28.2 lineage variant could be successfully isolated and characterization could be performed. Pathogenicity of the isolate was demonstrated in Syrian hamster model and the findings of neutralization reduction is of great concern and point towards the need for screening the vaccines for efficacy.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Cricetinae , Disease Models, Animal , Humans , Lung , Virulence
18.
Lancet ; 398(10317): 2173-2184, 2021 12 11.
Article in English | MEDLINE | ID: covidwho-1586227

ABSTRACT

BACKGROUND: We report the clinical efficacy against COVID-19 infection of BBV152, a whole virion inactivated SARS-CoV-2 vaccine formulated with a toll-like receptor 7/8 agonist molecule adsorbed to alum (Algel-IMDG) in Indian adults. METHODS: We did a randomised, double-blind, placebo-controlled, multicentre, phase 3 clinical trial in 25 Indian hospitals or medical clinics to evaluate the efficacy, safety, and immunological lot consistency of BBV152. Adults (age ≥18 years) who were healthy or had stable chronic medical conditions (not an immunocompromising condition or requiring treatment with immunosuppressive therapy) were randomised 1:1 with a computer-generated randomisation scheme (stratified for the presence or absence of chronic conditions) to receive two intramuscular doses of vaccine or placebo administered 4 weeks apart. Participants, investigators, study coordinators, study-related personnel, the sponsor, and nurses who administered the vaccines were masked to treatment group allocation; an unmasked contract research organisation and a masked expert adjudication panel assessed outcomes. The primary outcome was the efficacy of the BBV152 vaccine in preventing a first occurrence of laboratory-confirmed (RT-PCR-positive) symptomatic COVID-19 (any severity), occurring at least 14 days after the second dose in the per-protocol population. We also assessed safety and reactogenicity throughout the duration of the study in all participants who had received at least one dose of vaccine or placebo. This report contains interim results (data cutoff May 17, 2021) regarding immunogenicity and safety outcomes (captured on days 0 to 56) and efficacy results with a median of 99 days for the study population. The trial was registered on the Indian Clinical Trials Registry India, CTRI/2020/11/028976, and ClinicalTrials.gov, NCT04641481 (active, not recruiting). FINDINGS: Between Nov 16, 2020, and Jan 7, 2021, we recruited 25 798 participants who were randomly assigned to receive BBV152 or placebo; 24 419 received two doses of BBV152 (n=12 221) or placebo (n=12 198). Efficacy analysis was dependent on having 130 cases of symptomatic COVID-19, which occurred when 16 973 initially seronegative participants had at least 14 days follow-up after the second dose. 24 (0·3%) cases occurred among 8471 vaccine recipients and 106 (1·2%) among 8502 placebo recipients, giving an overall estimated vaccine efficacy of 77·8% (95% CI 65·2-86·4). In the safety population (n=25 753), 5959 adverse events occurred in 3194 participants. BBV152 was well tolerated; the same proportion of participants reported adverse events in the vaccine group (1597 [12·4%] of 12 879) and placebo group (1597 [12·4%] of 12 874), with no clinically significant differences in the distributions of solicited, unsolicited, or serious adverse events between the groups, and no cases of anaphylaxis or vaccine-related deaths. INTERPRETATION: BBV152 was highly efficacious against laboratory-confirmed symptomatic COVID-19 disease in adults. Vaccination was well tolerated with no safety concerns raised in this interim analysis. FUNDING: Bharat Biotech International and Indian Council of Medical Research.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/prevention & control , Immunogenicity, Vaccine , Vaccines, Inactivated/immunology , Adjuvants, Immunologic , Adult , COVID-19 Nucleic Acid Testing , Double-Blind Method , Female , Humans , India , Male
19.
2021.
Preprint in English | Other preprints | ID: ppcovidwho-296360

ABSTRACT

Covishield comprises the larger proportion in the vaccination program in India. Hence, it is of utmost importance to understand neutralizing capability of vaccine against the B.1.617.1 variant which is considered to responsible for surge of the cases in India. The neutralizing-antibody (NAb) titer against B.1.167.1 and prototype B.1 variant (D614G) was determined of the vaccine sera (4 weeks after second dose) of COVID-19 naïve subjects (n=43) and COVID-19 recovered subjects (n=18). The results demonstrated that sera of COVID-19 recovered subjects (n=18) who received two doses of Covishield have higher NAb response compared to the COVID-19 naive with a significant difference (p<0.0001) in NAb titer against B.1 and B.1.617.1 In-spite of reduction in the neutralizing titer against B.1.617.1 variant;Covishield vaccine-induced antibodies are likely to be protective to limit the severity and mortality of the disease in the vaccinated individuals.

20.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-293424

ABSTRACT

The emergence of SARS-CoV-2 Delta variant and its derivatives has created grave public health problem worldwide. The high transmissibility associated with this variant has led to daily increase in the number of SARS-CoV-2 infections. Delta variant has slowly dominated the other variants of concern. Subsequently, Delta has further mutated to Delta AY.1 to Delta AY.126. Of these, Delta AY.1 has been reported from several countries including India and considered to be highly infectious and probable escape mutant. Considering the possible immune escape, we had already evaluated the efficacy of the BBV152 against Delta and Delta AY.1 variants. Here, we have evaluated the neutralizing potential of sera of COVID-19 naive vaccinees (CNV) immunized with two doses of vaccine, COVID-19 recovered cases immunized with two doses of vaccine (CRV) and breakthrough infections (BTI) post immunization with two doses of vaccine against Delta, Delta AY.1 and B.1.617.3 using 50% plaque reduction neutralization test (PRNT50). Our study observed low NAb titer in CNV group against all the variants compared to CRV and BTI groups. Delta variant has shown highest reduction of 27.3-fold in NAb titer among CNV group compared to other groups and variants. Anti-S1-RBD IgG immune response among all the groups was also substantiated with NAb response. Compromised neutralization was observed against Delta and Delta AY.1 compared B.1 in all three groups. However, it provided protection against severity of the disease and fatality.

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