scholarly journals Neutralization potential of Covishield vaccinated individuals against B.1.617.1

2021 ◽  
Author(s):  
Pragya Yadav ◽  
Gajanan N Sapkal ◽  
Priya Abraham ◽  
Gururaj Deshpande ◽  
Dimpal Nyayanit ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
Vaccination Program ◽  
Neutralization Potential ◽  
Significant Difference

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 naive 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.

scholarly journals Neutralization of SARS-CoV-2 Omicron variant by sera from BNT162b2 or Coronavac vaccine recipients

2021 ◽  
Author(s):  
Lu Lu ◽  
Bobo Mok ◽  
Linlei Chen ◽  
Jacky Chan ◽  
Owen Tsang ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Neutralizing Antibody ◽  
World Health ◽  
Whole Genome Sequence ◽  
Live Virus ◽  
Significant Difference ◽  
Antibody Titers ◽  
Ancestral Virus ◽  
Health Organization

Background The SARS-CoV-2 Omicron variant, designated as a Variant of Concern(VOC) by the World Health Organization, carries numerous spike protein mutations which have been found to evade neutralizing antibodies elicited by COVID-19 vaccines. The susceptibility of Omicron variant by vaccine-induced neutralizing antibodies are urgently needed for risk assessment. Methods Omicron variant strains HKU691 and HKU344-R346K were isolated from patients using TMPRSS2-overexpressing VeroE6 cells. Whole genome sequence was determined using nanopore sequencing. Neutralization susceptibility of ancestral lineage A virus and the Omicron, Delta and Beta variants to sera from 25 BNT162b2 and 25 Coronavac vaccine recipients was determined using a live virus microneutralization assay. Results The Omicron variant strain HKU344-R346K has an additional spike R346K mutation, which is present in 8.5% of strains in GISAID database. Only 20% and 24% of BNT162b2 recipients had detectable neutralizing antibody against the Omicron variant HKU691 and HKU344-R346K, respectively, while none of the Coronavac recipients had detectable neutralizing antibody titer against either Omicron isolates. For BNT162b2 recipients, the geometric mean neutralization antibody titers(GMT) of the Omicron variant isolates(5.43 and 6.42) were 35.7-39.9-fold lower than that of the ancestral virus(229.4), and the GMT of both omicron isolates were significantly lower than those of the beta and delta variants. There was no significant difference in the GMT between HKU691 and HKU344-R346K. Conclusions Omicron variant escapes neutralizing antibodies elicited by BNT162b2 or CoronaVac. The additional R346K mutation did not affect the neutralization susceptibility. Our data suggest that the Omicron variant may be associated with lower COVID-19 vaccine effectiveness.

scholarly journals Studies on the level of neutralizing antibodies produced by inactivated COVID-19 vaccines in the real world

2021 ◽  
Author(s):  
Haiying Zhang ◽  
Yuyuan Jia ◽  
Ying Ji ◽  
Xu Cong ◽  
Yan Liu ◽  
...  
Keyword(s):  
Real World ◽  
Linear Correlation ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Igg Antibodies ◽  
Serum Samples ◽  
The Real ◽  
Significant Difference ◽  
Positive Rate ◽  
High Linear Correlation

Background Although effective vaccines have been developed against COVID-19, the level of neutralizing antibodies (Nabs) induced after vaccination in the real world is still unknown. To evaluate the level and persistence of NAbs induced by two inactivated COVID-19 vaccines in China. Methods and findings Serum samples were collected from 1,335 people aged 18 and over who were vaccinated with COVID-19 inactivated vaccine in Peking University People's Hospital from January 19 to June 23, 2021, for detection of COVID-19 antibodies. The WHO standard of SARS-CoV-2 NAbs was detected. The coefficients of variation between the detection results and the true values of the NAbs detected by the WHO standard were all lower than the WHO international standard 3% after the dilution of the original and the dilution of the theoretical concentrations of 500 IU/mL, 250 IU/mL, 125 IU/mL, 72.5 IU/mL, 36.25 IU/mL and 18.125 IU/mL. On day 11-70, the positive rate of NAbs against COVID-19 was 82% to 100%; From day 71 to 332, the positive rate of NAbs decreased to 27%. The level of NAbs was significantly higher at 3-8 Weeks than at 0-3 Weeks. There was a high linear correlation between NAbs and IgG antibodies in 1335 vaccinated patients. NAbs levels were decreased in 31 of 38 people (81.6%) at two time points after the second dose of vaccine. There was no significant difference in age between the group with increased and decreased neutralizing antibody levels (x2 =-0.034, P>0.05). The positive rate of NAbs in the two-dose vaccine group (77.3%) was significantly higher than that in the one-dose group (18.1%), with statistical difference (x2=312.590, P<0.001). A total of 206 people who were 11-70 days after receiving the second dose were tested and divided into three groups: 18-40 years old, 41-60 years old and >60 years old. The positive rates of NAbs in three groups (18-40 years old, 41-60 years old and >60 years old) were 95.14%, 78.43% and 81.8%, respectively. The positive rate of NAbs was significantly higher in 18-40 years old than in 41-60 years old (x2=12.547, P <0.01). The titer of NAbs in 18-40 years old group was significantly higher than that in 41-60 years old group (t=-0.222, P <0.01). The positive rate of NAbs in male group (89.32%) was lower than in female (91.26%), but there was no significant difference (x2=0.222, P >0.05). Conclusions The positive rate of NAbs was the highest from 10 to 70 days after the second dose of vaccine, and the positive rate gradually decreased as time went by. There was a high linear correlation between COVID-19 NAbs and IgM/IgG antibodies in vaccinators, suggesting that in cases where NAbs cannot be detected, IgM/IgG antibodies can be detected instead. The level of NAbs produced after vaccination was affected by age, but not by gender. The highest levels of NAbs were produced between shots 21 to 56 days apart, suggesting that 21 to 56 days between shots is suitable for vaccination.

scholarly journals SARS-CoV-2 Neutralizing Antibody Levels Post COVID-19 Vaccination Based on ELISA Method—A Small Real-World Sample Exploration

Vaccines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1139
Author(s):  
Xiaoguang Li ◽  
Chao Liang ◽  
Xiumei Xiao
Keyword(s):  
Neutralizing Antibodies ◽  
Detection Rate ◽  
Neutralizing Antibody ◽  
Population Characteristics ◽  
Detection Rates ◽  
Positive Detection Rate ◽  
Significant Difference ◽  
Positive Rate ◽  
Antibody Levels

This study investigated the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibodies following inoculation with the coronavirus disease (COVID-19) vaccine. From June to July 2021, 127 participants who had completed COVID-19 vaccination (inactivated SARS-CoV-2 vaccine, 64; CoronaVac, 61; CanSino, 2) were recruited and tested using SARS-CoV-2 neutralizing antibody kits. The positive detection rate (inhibition of neutralizing antibodies ≥ 30%) was calculated and stratified according to population characteristics and inoculation time. The positive rate of neutralizing antibody was 47.22% (17/36) in men and 53.85% (49/91) in women, and 54.55% (24/44) in BMI ≥ 24 and 50.60% (42/83) in BMI < 24. Age was stratified as 20–29, 30–39, 40–49, and ≥50; positive detection rates of SARS-CoV-2 neutralizing antibodies were observed in 60.00% (24/40), 50.00% (21/42), 48.39% (15/31), and 42.86% (6/14), respectively, but with no significant difference (x2 = 1.724, p = 0.632). Among 127 vaccinated participants, 66 (51.97%) were positive. The positive detection rate was 63.93% (39/61) with CoronaVac and 42.19% (27/64) with the inactivated SARS-CoV-2 vaccine (significance x2 = 5.927, p = 0.015). Multivariate analysis revealed a significant difference in vaccination times, with average vaccination weeks in the positive and negative groups of 11.57 ± 6.48 and 17.87 ± 9.17, respectively (t= −4.501, p < 0.001). The positive neutralizing antibody rate was 100.00%, 60.00%, 58.33%, 55.56%, 43.14%, 28.57%, and 0.00% at 2–4, 5–8, 9–12, 13–16,17–20, 21–24, and >24 weeks, respectively (x2 = 18.030, p = 0.006). Neutralizing antibodies were detected after COVID-19 inoculation, with differences relating to inoculation timing. This study provides a reference for vaccine evaluation and follow-up immunization strengthening.

scholarly journals Controlling bovine brucellosis in the state of São Paulo, Brazil: results after ten years of a vaccination program

2016 ◽  
Vol 37 (5Supl2) ◽  
pp. 3505 ◽  
Author(s):  
Ricardo Augusto Dias ◽  
Ana Paula Cunha Belchior ◽  
Rodrigo De Souza Ferreira ◽  
Rita Coelho Gonçalves ◽  
Ricardo Souza Costa Barão de Aguiar ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Sao Paulo ◽  
The State ◽  
Vaccination Program ◽  
São Paulo ◽  
Bovine Brucellosis ◽  
Paulo State ◽  
Significant Difference ◽  
Strain Vaccine ◽  
São Paulo State

A cross- sectional study was carried out, between May and November 2011, to estimate the situation of the bovine brucellosis in São Paulo State, 10 years after the commencement of the vaccination of the heifers with the S19 strain. The State was divided into seven regions and in each of them, 300 farms with reproductive activity were randomly chosen and considered as primary sample units. A fixed number of cows was randomly selected and tested for antibodies against Brucella spp. A farm was considered infected if at least one female tested positive. In the selected farms, an epidemiological questionnaire was administered which focused on herd traits as well as husbandry and sanitary practices that could be associated with the risk of infection. The prevalence (percentile, [95% confidence interval]) of infected herds was 10.2% [8.8-11.8] for the State, and for the regions, it varied from 7.3% [4.7-11.2] to 12.3% [8.8-16.8], not showing significant difference between different regions. The apparent prevalence of positive farms in the State and regions remained similar to the prevalence observed 10 years before. The prevalence of positive animals was 2.4% [1.8-3.1] in the State and varied from 1.1% [0.6-2] to 3.5% [1.7-7.1] in the regions, not showing significant difference between regions. Again, there was no difference in the prevalence of positive animals after 10 years of the vaccination program. The risk factors (odds ratio, 95% confidence interval) associated with bovine brucellosis in the State included number of cows ? 24 (3.08, 2.22-4.27) and the acquisition of breeding animals (1.33, 0.95-1.87). The São Paulo State should conduct systematic vaccination coverage of above 80% of the eligible heifers with the S19 strain vaccine annually. Moreover, the State should emphatically use RB51 strain vaccine in females above 8 months of age not vaccinated with S19 strain vaccine. An efficient animal health education program to orientate farmers to test replacement animals for brucellosis prior to introduction in their herds should also be implemented.

scholarly journals Limited ability of humoral immune responses in control of viremia during infection with SIVsmmD215 strain

Blood ◽  
2009 ◽  
Vol 113 (18) ◽  
pp. 4250-4261 ◽  
Author(s):  
Thaidra Gaufin ◽  
Rajeev Gautam ◽  
Melissa Kasheta ◽  
Ruy Ribeiro ◽  
Erin Ribka ◽  
...  
Keyword(s):  
Immune Responses ◽  
Antibody Production ◽  
Neutralizing Antibody ◽  
Viral Loads ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Significant Difference ◽  
Anti Cd20 ◽  
And Control ◽  
The Impact

AbstractWe investigated the impact of rhesus macaque (RM) B-cell depletion before inoculation with the isolate SIVsmmD215. Seven RMs were treated every 3 weeks with 50 mg/kg of an anti-CD20 antibody (rituximab) starting 7 days before inoculation for 2 (n = 4) and 5 (n = 3) months. Four control animals received no antibody. Three animals were completely depleted of CD20+ B cells, but 4 were only partially depleted of CD20 cells in the LNs and intestine. The decrease in antibody production was consistent with the efficacy of tissue CD20 depletion. Seroconversion and neutralizing antibody production was significantly delayed in animals showing complete tissue CD20 depletion and remained at low titers in all CD20-depleted RMs. Surprisingly, there was no significant difference in acute or chronic viral loads between CD20-depleted and control animal groups. There was a tendency for lower viral set points in CD20-depleted animals. At 6 weeks after inoculation, cellular immune responses were significantly stronger in CD20-depleted animals than in controls. There was no significant difference in survival between CD20-depleted and control animals. Our data suggest that a deficiency of Ab responses did not markedly affect viral replication or disease progression and that they may be compensated by more robust cellular responses.

scholarly journals A Self-Assembling Ferritin Nanoplatform for Designing Classical Swine Fever Vaccine: Elicitation of Potent Neutralizing Antibody

Vaccines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 45
Author(s):  
Zekai Zhao ◽  
Xinghua Chen ◽  
Yibao Chen ◽  
Hui Li ◽  
Kui Fang ◽  
...  
Keyword(s):  
Classical Swine Fever ◽  
Neutralizing Antibody ◽  
Vaccine Strategy ◽  
Viral Pathogens ◽  
Blocking Antibody ◽  
Self Assembling ◽  
E2 Glycoprotein ◽  
Significant Difference ◽  
Half Dose

Protein-based self-assembling nanoplatforms exhibit superior immunogenicity compared with soluble antigens. Here, we present a comprehensive vaccine strategy for displaying classical swine fever virus (CSFV) E2 glycoprotein on the surface of ferritin (fe) nanocages. An E2-specific blocking antibody assay showed that the blocking rates in pE2-fe/Gel02 (84.3%) and a half-dose cohort of E2-fe/Gel02 (81.9%) were significantly higher (p < 0.05) than that in a ferritin-free cohort of pE2/Gel02 (62.7%) at 21 days post immunization (dpi) in vivo. Furthermore, quantitation of neutralizing potency revealed that a highly significant difference (p < 0.001) was observed between the pE2-fe/Gel02 cohort (1:32, equivalent to live-attenuated strain C at 1:32) and the pE2/Gel02 cohort (1:4) at 21 dpi. Moreover, the innate immune cytokines of IL-4 and IFN-γ activated by the half-dose (20 μg) cohort of E2-fe/Gel02 were equivalent to those elicited by the full dose (40 μg) of purified E2 in the pE2/Gel02 cohort at most time points. In conclusion, we successfully obtained an antigen-displaying E2-ferritin nanoplatform and confirmed high ferritin-assisted humoral and cellular immunities. Our results provided a novel paradigm of self-assembling nanovaccine development for the defense and elimination of potentially pandemic infectious viral pathogens.

scholarly journals The effect of vaccination regimen on the transfer of foot and mouth disease antibodies from the sow to her piglets

1984 ◽  
Vol 93 (1) ◽  
pp. 123-131 ◽  
Author(s):  
M. J. Francis ◽  
L. Black
Keyword(s):  
Neutralizing Antibodies ◽  
Foot And Mouth Disease ◽  
Neutralizing Antibody ◽  
Mouth Disease ◽  
Oil Emulsion ◽  
Fmd Virus ◽  
Significant Difference ◽  
Foot And Mouth ◽  
Antibody Titres ◽  
Antibody Class

SUMMARYFour groups of pregnant sows were inoculated with type O1 foot and mouth disease (FMD) oil emulsion vaccine at various times before farrowing and samples of the sow's serum, colostrum and milk, and piglet's serum, collected during the first week after farrowing, were analysed for FMD virus neutralizing activity.No FMD neutralizing antibodies were detectable in the piglets serum at birth but they were present 1·5 h after suckling and peak titres were reached 1–3 days later. There was no significant difference between the antibody titres of colostrum samples collected from different teats at farrowing. However, similar samples collected 3 days later showed significant (P < 0·005) fore to hind variation. The principal FMD virus neutralizing antibody class present in the sow's serum at farrowing and in their 3-day-old piglets was governed by the inoculation schedule employed. When the last vaccinations were given ≃ 30 days before farrowing (dbf) the predominant FMD virus neutralizing class was IgG. However, when the sows were vaccinated only ≃ 12 dbf the predominant class was IgM. A significant correlation was observed between the sow's serum titres and colostrum titres at farrowing (r = 0·90), and also between sows colostrum titres at farrowing and their 3-day-old piglets serum titres (r = 0·99).

scholarly journals Antibody Response to the BNT162b2 mRNA COVID-19 Vaccine in Subjects with Prior SARS-CoV-2 Infection

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 422
Author(s):  
Federico Gobbi ◽  
Dora Buonfrate ◽  
Lucia Moro ◽  
Paola Rodari ◽  
Chiara Piubelli ◽  
...  
Keyword(s):  
Antibody Response ◽  
Neutralizing Antibodies ◽  
Natural Infection ◽  
Vaccine Dose ◽  
Neutralizing Antibody ◽  
Immune Memory ◽  
Effective Response ◽  
Infected People ◽  
Significant Difference ◽  
Antibody Titers

Although antibody levels progressively decrease following SARS-CoV-2 infection, the immune memory persists for months. Thus, individuals who naturally contracted SARS-CoV-2 are expected to develop a more rapid and sustained response to COVID-19 vaccines than naïve individuals. In this study, we analyzed the dynamics of the antibody response to the BNT162b2 mRNA COVID-19 vaccine in six healthcare workers who contracted SARS-CoV-2 in March 2020, in comparison to nine control subjects without a previous infection. The vaccine was well tolerated by both groups, with no significant difference in the frequency of vaccine-associated side effects, with the exception of local pain, which was more common in previously infected subjects. Overall, the titers of neutralizing antibodies were markedly higher in response to the vaccine than after natural infection. In all subjects with pre-existing immunity, a rapid increase in anti-spike receptor-binding domain (RBD) IgG antibodies and neutralizing antibody titers was observed one week after the first dose, which seemed to act as a booster. Notably, in previously infected individuals, neutralizing antibody titers 7 days after the first vaccine dose were not significantly different from those observed in naïve subjects 7 days after the second vaccine dose. These results suggest that, in previously infected people, a single dose of the vaccine might be sufficient to induce an effective response.

scholarly journals SARS-CoV-2 Seroprevalence and Neutralizing Antibody Response after the First and Second COVID-19 Pandemic Wave in Croatia

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 774
Author(s):  
Tatjana Vilibic-Cavlek ◽  
Vladimir Stevanovic ◽  
Maja Ilic ◽  
Ljubo Barbic ◽  
Krunoslav Capak ◽  
...  
Keyword(s):  
Antibody Response ◽  
Age Groups ◽  
Neutralizing Antibody ◽  
Seroprevalence Rate ◽  
Age Related ◽  
Significant Difference ◽  
Antibody Titers ◽  
Binding Antibody ◽  
Novel Coronavirus ◽  
Pandemic Wave

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus with a pandemic spread. So far, a total of 358,581 SARS-CoV-2 cases and 8152 deaths were reported in Croatia. We analyzed the seroprevalence and neutralizing (NT) antibody response in the Croatian general population after the first (May–July 2020) and second (December 2020–February 2021) pandemic wave. Initial serological testing was performed using a commercial ELISA, with confirmation of reactive samples by a virus neutralization test (VNT). A significant difference in the overall seroprevalence rate was found after the first (ELISA 2.2%, VNT 0.2%) and second waves (ELISA 25.1%, VNT 18.7%). Seropositive individuals were detected in all age groups, with significant differences according to age. The lowest prevalence of NT antibodies was documented in the youngest (<10 years; 16.1%) and the oldest (60–69/70+ years; 16.0% and 12.8%, respectively) age groups. However, these age groups showed the highest median NT titers (32–64). In other groups, seropositivity varied from 19.3% to 21.5%. A significant weak positive correlation between binding antibody level as detected by ELISA and VNT titer (rho = 0.439, p < 0.001) was observed. SARS-CoV-2 NT antibody titers seem to be age-related, with the highest NT activity in children under 10 years and individuals above 50 years.

scholarly journals COVID-19 Repeated Convalescent Plasma Collection: Analysis of 149 Donations from 88 French Military Health Workers

2021 ◽  
pp. 1-6
Author(s):  
Pierre-Louis Conan ◽  
Cécile Ficko ◽  
Marine Chueca ◽  
Carole Rolland ◽  
Olivier Javaudin ◽  
...  
Keyword(s):  
Antibody Titer ◽  
Neutralizing Antibodies ◽  
Health Workers ◽  
Young Patients ◽  
Neutralizing Antibody ◽  
Military Health ◽  
Service Workers ◽  
The Third ◽  
Significant Difference ◽  
Antibody Titers

<b><i>Background:</i></b> Passive therapy with convalescent plasma (CP) could be an effective and safe treatment option in COVID-19 patients. Neutralizing antibodies present in CP generated in response to SARS-CoV-2 infection and directed against the receptor-binding domain of the spike protein are considered to play a major role in the viral clearance. CP infusion may also contribute to the modulation of the immune response through its immunomodulatory effect. We describe for the first time the effectiveness of a CP collection protocol from repeated donations in young patients. <b><i>Materials and Methods:</i></b> We enrolled health service workers who experienced mild to moderate COVID-19 and from whom several donations have been collected. No minimal severity threshold and no biological cure criteria were required. Donors could return to a second plasma donation 14 days after the first donation. A minimal neutralizing antibody titer of 1:40 was considered for clinical use. <b><i>Results:</i></b> Eighty-eight donors were included (median age 35 [28–48] years, 41 women), and 149 plasma products were collected. COVID-19 were mainly WHO stage 2 infections (96%). Among the 88 first donations, 76% had neutralizing antibody titers higher than or equal to 1:40. Eighty-eight percent of donors who came for a second donation had a neutralizing antibody titer of 1:40. Median durations were 15 (15–19) and 38 (33–46) days from the first to the second donation and from recovery to the second donation, respectively. Sixty-nine percent of donors who came for a third donation had a neutralizing antibody titer of 1:40. Median durations were 16 (13–37) and 54 (49–61) days from the second to the third donation and from recovery to the third donation, respectively. No significant difference was observed between the IgG ratio and the age of the donors or the time between recovery and donation. The average IgG ratio did not significantly vary between donations. When focused on repeated blood donors, no significant differences were observed either. <b><i>Conclusion:</i></b> The recruitment of young patients with a mild to moderate CO­VID-19 course is an efficient possibility to collect CP with a satisfactory level of neutralizing antibodies. Repeated donations are a well-tolerated and effective way of CP collection.

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