Positive Neutralizing Antibody Research Articles

Performance evaluation of four kits for the detection of neutralizing antibody against SARS-CoV-2 in human serum

To evaluate four novel SARS-CoV-2 neutralizing antibody assay kits' application in neutralizing antibodies of population. Questionnaires from the voluntary participating researchers and selected the qualified questionnaires to analyse. For negative and positive coincidence rate, four novel SARS-Cov-2 neutralization antibody assay kits were tested. For within-run and between-run Precision verification study, four serum samples with two high and two low titer neutralizing antibodies were used to analyse. Based on the questionnaires, 175 qualified samples were divided into two groups. (1) negative neutralizing antibodies group: 31 samples had not been infected with the novel SARS-Cov-2 nor received the vaccine within the past one year; (2) positive neutralizing antibodies group: 144 samples were infected by COVID-19. There was 28 negative and 3 positive neutralizing antibodies of the individuals among the 31 negative samples which based on the questionnaires. The negative rates of 28 negative individules tested by GenScript, Vazyme and Hygeianey were 82.14 %, 60.71 % and 17.85 %, while the positive rates of the 147 positive samples were 93.87 %, 95.23 % and 100 %. The within-run coefficient of variations (C·V) of PBNAs, GenScript, Vazyme and Hygeianey were 11.49 %, 9.12 %, 7.97 % and 7.48 %, while the between-run coefficient of variations (C·V) were 21.37 %, 14.21 %, 12.29 % and 11.78 %. Due to the large within-run and between-run coefficient of variations, PBNAs was not suitable for large-scale promotion, while ELISAs could be leveraged for routine monitoring the titer of neutralizing antibodies against SARS-CoV-2.

Post COVID-19 vaccination binding and neutralizing antibody with or without previous infection: An 18-month longitudinal study in Indonesia.

Due to the persisting development of SARS-CoV-2 variants, studies on the kinetics, duration, and function of antibodies are essential for vaccine development and long-term immunity prediction. This longitudinal study examined post-vaccination antibody responses in people after receiving CoronaVac or ChAdOx1 vaccines with or without a history of SARS-CoV-2 infection. Conducted in Indonesia between August 2021 and May 2023, this study involved 121 participants divided into two groups based on the received vaccine types and monitored for 18 months post-second dose vaccination by assessing the binding antibody (BAb) level and neutralizing antibody (NAb) inhibition rate at six time points. The study also documented the participants' age, gender, and body mass index (BMI). Before the first dose vaccination, 85 (70.2%) participants were reactive BAb (defined by BAb level ≥50 AU/mL) indicating a history of infection. In the CoronaVac group, only 53.1% were reactive BAb. However, 100% of participants were positive NAb (defined by NAb inhibition rate ≥30%), which indicates a past history of infection with low initial or rapidly decreasing BAb levels. In the ChAdOx1 group, 81.9% of participants were reactive, while only 54.2% were positive NAb, suggesting a recent infection with a high BAb level but a relatively low NAb inhibition rate. During the 18 months post-second dose vaccination, the BAb levels fluctuated. However, 100% of participants were positive NAb. No significant difference in antibody response was documented among participants with or without infection history. Also, no significant impact was presented by the factors of sex, age, and BMI. The findings highlight the crucial of the vaccine in public health and how vaccination strategies could be optimized effectively during and after the post-pandemic.

Immunogenicity, clinical efficacy, and safety of the sinopharm (BBIBP-CorV) SARS-CoV-2 vaccine among people with multiple sclerosis receiving disease-modifying therapies: a prospective cohort study

BackgroundTo investigate the safety (adverse events [AEs] and post-vaccination multiple sclerosis [MS] activity within 6 weeks), clinical efficacy (protection against coronavirus disease 2019 [COVID-19]), and vaccine-induced humoral immunogenicity (SARS-CoV-2 neutralizing antibody, anti-nucleocapsid IgG, and anti-spike IgG) of the Sinopharm (BBIBP-CorV) vaccine among people with MS (PwMS) receiving different disease-modifying therapies (DMTs).MethodsThis prospective cohort study was conducted between November 2021 and May 2022. PwMS were followed for six months after the 2nd dose of vaccination. Antibody responses were measured 2–16 weeks after the 2nd dose injection. Multivariate logistic regression was employed to assess the impact of each DMT on dichotomous antibody responses, adjusting for age, sex, MS phenotype, expanded disability status scale, disease duration, and vaccination-antibody titration interval.ResultsAmong the 261 screened PwMS, 209 (aged 38.23 ± 9.73 years, female: 70.8%; relapsing-remitting MS: 80.4%) were included. The frequencies of experiencing non-serious AEs and post-vaccination MS activity were 66.0% and 4.8%, respectively. Breakthrough COVID-19 infection was observed in 14.8% of the PwMS. A subcohort of 125 PwMS was assessed for antibody responses. Positive neutralizing antibodies, anti-nucleocapsid IgG, and anti-spike IgG were detected in 36.8%, 35.2%, and 52.0% of the PwMS, respectively. Multivariate regression indicated a 96% (OR: 0.04 [95% CI: 0.00, 0.51], P = 0.013), 93% (OR: 0.07 [0.01, 0.64], P = 0.019), and 89% (OR: 0.11 [0.01, 0.96], P = 0.045) reduced odds of positive neutralizing antibody, anti-nucleocapsid IgG, and anti-spike IgG, respectively, among fingolimod-receivers. Additionally, anti-CD20s-receivers had 88% (OR: 0.12 [0.02, 0.85], P = 0.034) lower odds of being positive for anti-nucleocapsid IgG.ConclusionsBBIBP-CorV appeared to be well tolerated in PwMS, with promising clinical efficacy. However, a suboptimal humoral response was observed in PwMS receiving fingolimod and anti-CD20s. Future research should investigate the relationship between humoral responses and the frequency and severity of COVID-19 infection across various DMTs.

Vaccine challenges in CLL: a comprehensive exploration of efficacy of SARS-CoV-2 immunization for patients with chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is characterized by disease- and treatment-related immunosuppression. Patients with CLL comprise a vulnerable population to coronavirus disease 2019 (COVID-19), while the protective effect of COVID-19 vaccination remains uncertain.We conducted a systematic review to evaluate published data reporting response to COVID-19 vaccination in patients with CLL. The primary outcome was the rate of seropositivity after full primary vaccination, while secondary outcomes were rates of positive neutralizing antibodies, cellular responses, and adverse events. Response after booster doses of vaccination was also evaluated.Twenty-three studies of full primary vaccination (12 CLL-specific with 1747 patients, 11 with mixed hematologic diseases including 1044 patients with CLL) with a total of 2791 patients, and eight studies on booster doses with 389 patients were included in the analysis. The serologic response varied between studies with a median of 55%. Where reported, the median neutralizing antibody response rate was 61.2% and the cellular response rate was 44.2%. Poor serologic response was noted in patients under active treatment with anti-CD20 monoclonal antibodies, BCL2, and BTK inhibitors.The present review highlights the substantially impaired humoral and cellular response to COVID-19 vaccination in patients with CLL with patients under active treatment being the most vulnerable.

Coronavirus infection and neutralizing antibody responses among liver transplant recipients: single-center study

BackgroundLiver transplant (LT) recipients are classified as a high-risk group and should receive regular surveillance for COVID-19 and are expected to have higher viral load and prolonged viral shedding. Virus-specific neutralizing antibodies (NAb), induced by infection, can prevent viral infection by deactivating viral access to host receptors.AimTo estimate the incidence of SARS-CoV-2 infections and ascertain the levels of NAb among LT recipients.MethodThis cross-sectional study included LT recipients. The survey included 14 parameters about demography, date since operation, and immunosuppressant medications and 11 parameters about COVID-19 infection. NAb was done by electrochemiluminescence immunoassay.ResultsOnly 39 LT recipients responded to this survey. Their median age was 57, and 74.4% of them were men. Comorbidities were present in 64% of cases, and DM was the most common comorbidity. Immunosuppressants used were Tacrolimus in 56.4% and Tacrolimus with mycophenolate mofetil in 15.4%. Fifteen cases (38.5%) had suspected infection, and 2 (5.1%) had confirmed infection. Three patients (17.6%) were hospitalized with no mortality. NAb was done in 34 cases, and it was positive in 5 cases (14.7%) with a median level (range) of 0.075 (0.04–27). Three out of 5 cases with a positive NAb test did not give a history of either suspected or confirmed COVID-19 infection.ConclusionCOVID-19 surveillance in LT recipients is important and suggests a relatively favorable clinical course despite the presumed challenges of immunosuppression. COVID-19 was associated with low hospitalization in LT recipients. NAb indicates a potential immune response even in asymptomatic LT recipients.Trial registrationClinical Trial.gov NCT04565782. September 15 2022.

Efficacy, immunogenicity, and safety of COVID-19 vaccines in individuals with liver cirrhosis: a rapid review and meta-analysis.

The emergence of coronavirus disease 2019 (COVID-19) vaccines has been a remarkable advancement. However, the efficacy, immunogenicity, and safety of these vaccines in individuals with liver cirrhosis require careful evaluation due to their compromised immune status and potential interactions with underlying liver disease. The present study aimed to evaluate the safety and efficacy of COVID-19 vaccines in liver cirrhosis patients. In the present study, we searched international databases, including Google Scholar, PubMed, Scopus, Embase, and Web of Science. The search strategy was carried out by using keywords and MeSH (Medical Subject Headings) terms. STATA ver. 15.0 (Stata Corp., USA) was used to analyze the data statistically. The analysis was performed using the random-effects model. We also used the chi-square test and I2 index to calculate heterogeneity among studies. For evaluating publication bias, Begg's funnel plots and Egger's tests were used. A total of 4,831 liver cirrhosis patients with COVID-19 were examined from 11 studies. The rate of hospitalization in the patients with liver cirrhosis was 17.6% (95% confidence interval [CI], 9%-44%). The rate of fever in the patients with liver cirrhosis was 4.5% (95% CI, 0.9%-8.1%). The rate of positive neutralizing antibodies in the patients with liver cirrhosis was 82.5% (95% CI, 69.8%-95.1%). Also, the rates of seroconversion after the second vaccination in patients with liver cirrhosis and the control group were 96.6% (95% CI, 92.0%-99.0%), and 99.7% (95% CI, 99.0%-100.0%), respectively. COVID-19 vaccines have demonstrated promising efficacy, immunogenicity, and safety profiles in individuals with liver cirrhosis, providing crucial protection against COVID-19-related complications.

2079. Maternal hybrid immunity to SARS-CoV-2 during pregnancy provides more durable infant antibody responses compared to natural infection alone

Abstract Background Immunity from natural infection and vaccination (hybrid) may provide more durable SARS-CoV-2 antibody responses; whether this increases durability of maternally-derived antibody responses in infants is unknown. Methods Participants with prior SARS-CoV-2 infection in pregnancy (anti-nucleocapsid [anti-N] IgG+ on enrollment or prior RT-PCR+ or antigen+) were enrolled between January 2021-August 2022. Blood samples collected in pregnancy, delivery/birth, 0-< 3 and 3-6 months postpartum were tested for anti-S+ IgG by Abbott Architect (positive: ≥50 AU/mL) and neutralizing antibodies (serum dilution inhibited infection by 50% [ND50 heat] ≥20 and R2 ≥0.9). Results Among 107 participants at enrollment in pregnancy, median age was 32 years (IQR 30-35) and median gestational age was 31 weeks (IQR 19.1–37.9). At delivery (median 19.7 weeks [IQR 14.3-30.0] from SARS CoV-2 diagnosis), unvaccinated participants and their infants were less likely to have anti-S IgG+ (maternal 87%; cord 86%) or neutralizing antibodies (maternal 86%; cord 75%) than vaccinated (≥1 dose) participants and their infants (maternal and cord both 100% anti-S IgG+ and neutralizing antibodies) (all p≤0.01). By 6 months of age, the proportion of infants of mothers who remained unvaccinated at birth with anti-S IgG+ and neutralizing antibody declined to 50% and 14% (anti-S IgG+ and neutralizing antibody, respectively) compared to 100% (anti-S IgG+ and neutralizing antibody) among infants with vaccinated mothers (all p< 0.01). Infants with anti-S IgG+ or neutralizing antibodies born to unvaccinated mothers had lower median antibody levels at birth (anti-S IgG log10 2.95 vs. 4.40 AU/ml; neutralization log10 1:2.37 vs. 1:4.00, all p< 0.01) and through 6 months of age (anti-S IgG log10 1.95 vs. 3.84 AU/ml, p< 0.01; log10 neutralization 1:1.34 vs. 1:3.20, p=0.11) vs. infants with mothers vaccinated prior to delivery. Neutralizing antibody responses among A) pregnant people with prior SARS-CoV-2 infection during pregnancy and B) their infants by maternal vaccination status *† *Among participants and their infants with positive neutralizing antibodies (ND50 heat ≥20 and R2 ≥0.9). †Maternal vaccination status is at time of blood sample collection; for infants refers to maternal vaccination status at time of delivery. Conclusion SARS-CoV-2 infection alone during pregnancy did not provide persistent antibody responses in infants through 6 months of age. Maternal vaccination provided more durable antibody responses in participants with prior SARS-CoV-2, potentially providing protection to vulnerable infants in the months prior to their own COVID-19 vaccine eligibility. Disclosures Sylvia M. LaCourse, MD, MPH, Merck: Grant/Research Support Alex L. Greninger, MD, PhD, MS, MPhil, Abbott Diagnostics: central testing|Cepheid: central testing|Hologic Inc: central testing|Janssen Infectious Disease: central testing|Novavax, Inc.: central testing|Pfizer, Inc.: central testing Alisa B. Kachikis, MD, MSc, Merck: Grant/Research Support|Pfizer: Grant/Research Support Janet A. Englund, MD, Ark Biopharma: Advisor/Consultant|AstraZeneca: Advisor/Consultant|AstraZeneca: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Meissa Vaccines: Advisor/Consultant|Merck: Grant/Research Support|Moderna: Advisor/Consultant|Moderna: Grant/Research Support|Pfizer: Advisor/Consultant|Pfizer: Grant/Research Support|Sanofi Pasteur: Advisor/Consultant Alison L. Drake, PhD, MPH, Merck: Grant/Research Support

No Associations Between Physical Activity and Immunogenicity in SARS-CoV-2 Seropositive Patients With Autoimmune Rheumatic Diseases Prior to and After Vaccination.

To investigate the association between physical activity and immunogenicity among SARS-CoV-2 seropositive patients with autoimmune rheumatic diseases prior to and following a 2-dose schedule of CoronaVac (Sinovac inactivated vaccine). This was a prospective cohort study within an open-label, single-arm, phase 4 vaccination trial conducted in Sao Paulo, Brazil. In this substudy, only SARS-CoV-2 seropositive patients were included. Immunogenicity was assessed by seroconversion rates of total anti-SARS-CoV-2 S1/S2 immunoglobulin G (IgG), geometric mean titers of anti-S1/S2 IgG, frequency of positive neutralizing antibodies, and neutralizing activity before and after vaccination. Physical activity was assessed through a questionnaire. Model-based analyses were performed controlling for age (<60 or ≥60y), sex, body mass index (<25, 25-30, and >30kg/m2), and use of prednisone, immunosuppressants, and biologics. A total of 180 seropositive autoimmune rheumatic disease patients were included. There was no association between physical activity and immunogenicity before and after vaccination. This study suggests that the positive association between physical activity and greater antibody responses seen in immunocompromised individuals following vaccination is overridden by previous SARS-CoV-2 infection, and does not extend to natural immunity.

Immunogenicity of a Third Dose of BNT162b2 Vaccine among Lung Transplant Recipients-A Prospective Cohort Study.

Two doses of mRNA SARS-CoV-2 vaccines elicit an attenuated humoral immune response among immunocompromised patients. Our study aimed to assess the immunogenicity of a third dose of the BNT162b2 vaccine among lung transplant recipients (LTRs). We prospectively evaluated the humoral response by measuring anti-spike SARS-CoV-2 and neutralizing antibodies in 139 vaccinated LTRs ~4-6 weeks following the third vaccine dose. The t-cell response was evaluated by IFNγ assay. The primary outcome was the seropositivity rate following the third vaccine dose. Secondary outcomes included: positive neutralizing antibody and cellular immune response rate, adverse events, and COVID-19 infections. Results were compared to a control group of 41 healthcare workers. Among LTRs, 42.4% had a seropositive antibody titer, and 17.2% had a positive t-cell response. Seropositivity was associated with younger age (t = 3.736, p < 0.001), higher GFR (t = 2.355, p = 0.011), and longer duration from transplantation (t = -1.992, p = 0.024). Antibody titer positively correlated with neutralizing antibodies (r = 0.955, p < 0.001). The current study may suggest the enhancement of immunogenicity by using booster doses. Since monoclonal antibodies have limited effectiveness against prevalent sub-variants and LTRs are prone to severe COVID-19 morbidity, vaccination remains crucial for this vulnerable population.

Physical Activity: A Strategy to Improve Antibody Response to a SARS-CoV-2 Vaccine Booster Dose in Patients With Autoimmune Rheumatic Diseases.

Physical activity associates with improved immunogenicity following a 2-dose schedule of CoronaVac (Sinovac's inactivated SARS-CoV-2 vaccine) in patients with autoimmune rheumatic diseases (ARD). This study evaluates whether physical activity impacts vaccine-induced antibody responses to a booster dose in this population. This was a phase-4 trial conducted in São Paulo, Brazil. Patients with ARD underwent a 3-dose schedule of CoronaVac. One month after the booster, we assessed seroconversion rates of anti-SARS-CoV-2 S1/S2 IgG, geometric mean titers of anti-S1/S2 IgG, frequency of positive neutralizing antibodies, and neutralizing activity. Physical activity was assessed through questionnaire. Physically active (n = 362) and inactive (n = 278) patients were comparable for most characteristics; however, physically active patients were younger (P < .01) and had a lower frequency of chronic inflammatory arthritis (P < .01). Adjusted models showed that physically active patients had ∼2 times odds of seroconversion rates (OR: 2.09; 95% confidence interval, 1.22 to 3.61), ∼22% greater geometric mean titers of anti-S1/S2 IgG (22.09%; 95% confidence interval, 3.91 to 65.60), and ∼7% greater neutralizing activity (6.76%; 95% confidence interval, 2.80 to 10.72) than inactive patients. Patients with ARD who are physically active have greater odds of experiencing better immunogenicity to a booster dose of CoronaVac. These results support the recommendation of physical activity to improve vaccination responses, particularly for immunocompromised individuals.

Comparison of Pharmacokinetic Similarity, Immunogenicity, and Safety of Ustekinumab and BAT2206 in Healthy Chinese Male Subjects in a Double-Blind, Randomized, Single-Dose, Parallel-Group Phase I Trial.

We aimed to evaluate the similarity of BAT2206 to its originator, ustekinumab, including pharmacokinetic profiles, immunogenicity, and safety in healthy Chinese male subjects. This was a double-blinded, randomized, single-dose, parallel-group clinical trial, in which 270 healthy male subjects were enrolled to receive a single subcutaneous injection (45 mg) of either BAT2206 or ustekinumab (European Union or USA) at a 1:1:1 ratio. The pairwise pharmacokinetic similarities and the safety and immunogenicity of both drugs were evaluated and compared. The results showed that the 90% confidence interval of the geometric mean ratio for primary pharmacokinetic parameters (maximum plasma concentration and area under the plasma concentration-time curve from time zero to infinity) among BAT2206 and ustekinumab (USA or European Union sourced) groups were all within the predefined equivalent interval of 80-125%. Furthermore, all the groups had similar incidences of treatment-emergent adverse events, in which the majority of cases belonged to Common Terminology Criteria for the Classification of Adverse Events Grade 1 or 2. Anti-drug antibodies were detected in 54 (20.1%) subjects, namely 24 (26.7%), 13 (14.8%), and 17 (18.9%) patients in the BAT2206, ustekinumab (European Union), and ustekinumab (USA) groups, respectively. In contrast, the incidences of positive neutralizing antibodies were similar among the three groups. Pharmacokinetic similarity between BAT2206 and ustekinumab (USA or European Union sourced) was confirmed. The three groups had similar safety profiles, and the investigational drugs were well tolerated by subjects. This study was registered with ClinicalTrials.gov (NCT04371185).

Immunogenicity profiling and distinct immune response in liver transplant recipients vaccinated with SARS-CoV-2 inactivated vaccines.

SARS-CoV-2 vaccination has been recommended for liver transplant (LT) recipients. However, our understanding of inactivated vaccine stimulation of the immune system in regulating humoral and cellular immunity among LT recipients is inadequate. Forty-six LT recipients who received two-dose inactivated vaccines according to the national vaccination schedule were enrolled. The clinical characteristics, antibody responses, single-cell peripheral immune profiling, and plasma cytokine/chemokine/growth factor levels were recorded. Sixteen (34.78%) LT recipients with positive neutralizing antibody (nAb) were present in the Type 1 group. Fourteen and 16 LT recipients with undetected nAb were present in the Type 2 and Type 3 groups, respectively. Time from transplant and lymphocyte count were different among the three groups. The levels of anti-RBD and anti-S1S2 decreased with decreasing neutralizing inhibition rates. Compared to the Type 2 and Type 3 groups, the Type 1 group had an enhanced innate immune response. The proportions of B, DNT, and CD3+CD19+ cells were increased in the Type 1 group, whereas monocytes and CD4+ T cells were decreased. High CD19, high CD8+CD45RA+ cells, and low effector memory CD4+/naïve CD4+ cells of the T-cell populations were present in the Type 1 group. The Type 1 group had higher concentrations of plasma CXCL10, MIP-1 beta, and TNF-alpha. No severe adverse events were reported in all LT recipients. We identified the immune responses induced by inactivated vaccines among LT recipients and provided insights into the identification of immunotypes associated with the responders.

Safety and immunogenicity of COVID-19 vaccination in patients with hepatocellular carcinoma (CHESS-NMCID 2101): A multicenter prospective study.

Data on safety and immunogenicity of coronavirus disease 2019 (COVID‐19) vaccinations in hepatocellular carcinoma (HCC) patients are limited. In this multicenter prospective study, HCC patients received two doses of inactivated whole‐virion COVID‐19 vaccines. The safety and neutralizing antibody were monitored. Totally, 74 patients were enrolled from 10 centers in China, and 37 (50.0%), 25 (33.8%), and 12 (16.2%) received the CoronaVac, BBIBP‐CorV, and WIBP‐CorV, respectively. The vaccines were well tolerated, where pain at the injection site (6.8% [5/74]) and anorexia (2.7% [2/74]) were the most frequent local and systemic adverse events. The median level of neutralizing antibody was 13.5 (interquartile range [IQR]: 6.9–23.2) AU/ml at 45 (IQR: 19–72) days after the second dose of vaccinations, and 60.8% (45/74) of patients had positive neutralizing antibody. Additionally, lower γ‐glutamyl transpeptidase level was related to positive neutralizing antibody (odds ratio = 1.022 [1.003–1.049], p = 0.049). In conclusion, this study found that inactivated COVID‐19 vaccinations are safe and the immunogenicity is acceptable or hyporesponsive in patients with HCC. Given that the potential benefits may outweigh the risks and the continuing emergences of novel severe acute respiratory syndrome coronavirus 2 variants, we suggest HCC patients to be vaccinated against COVID‐19. Future validation studies are warranted.

Physical activity and antibody persistence 6 months after the second dose of CoronaVac in immunocompromised patients

This prospective cohort study within an open-label, single-arm, phase 4 vaccination trial (clinicaltrials.gov #NCT04754698) aimed to investigate the association between physical activity and persistent anti-SARS-CoV-2 antibodies 6 months after two-dose schedule of CoronaVac in autoimmune rheumatic diseases (ARD) patients (n=748). Persistent immunogenicity 6 months after the full-course vaccination was assessed using seroconversion rates of total anti-SARS-CoV-2 S1/S2 IgG, geometric mean titers of anti-S1/S2 IgG (GMT), and frequency of positive neutralizing antibodies (NAb). Physical activity was assessed trough questionnaire. Adjusted point estimates from logistic regression models indicated greater odds of seroconversion rates (OR: 1.5 [95%CI: 1.1 to 2.1]) and NAb positivity (OR: 1.5 [95%CI: 1.0 to 2.1]) in physically active patients and approximately 43% greater GMT (42.8% [95%CI: 11.9 to 82.2]) than inactive ones. In conclusion, among immunocompromised patients, being physically active was associated with an increment in antibody persistence through 6 months after a full-course of an inactivated SARS-CoV-2 vaccine.

IgG, IgM and neutralizing antibodies to SARS-COV-2 in medical workers during the year (2020-2021) before the start of mass vaccination

The purpose of the work is to assess the levels of IgG, IgM and neutralizing antibodies to SARS-CoV-2 in medical workers during the year (2020-2021) before the start of mass vaccination, depending on the presence of clinical symptoms and positive PCR test. It is established that people without antibodies to SARSCoV-2 do not have neutralizing antibodies. The antibody levels, as well as percentage of neutralization, were higher in individuals who had just recovered from Covid-19 and have positive PCR at the beginning of the disease compared to those who had no clinical manifestation. There was a positive correlation between the level of IgG and percentage of neutralization. In persons without pronounced clinical symptoms of coronavirus infection, moderately positive neutralizing antibodies prevail, whereas in the vast majority of recovered individuals they are highly positive.

Safety and Immunogenicity of a Booster Vaccination by CoronaVac or BNT162b2 in Previously Two-Dose Inactivated Virus Vaccinated Individuals with Negative Neutralizing Antibody.

COVID-19 has swept across the globe since 2019 and repeated waves of infection have been caused by different variants of the original SARS-CoV-2 (wild type), with the Omicron and Delta variants having dominated recently. Vaccination is among the most important measures in the absence of widespread use of antivirals for prevention of morbidity and mortality. Inactivated virus vaccine has been abundantly used in many countries as the primary two-dose regimen. We aim to study the safety and immunogenicity of CoronaVac (three-dose inactivated virus vaccine) and the BNT162b2 (two-dose inactivated virus vaccine followed by an mRNA vaccine) booster. Both CoronaVac and BNT162b2 boosters are generally safe and have good immunogenicity against the wild type SARS-CoV-2 and the Delta variant with the majority having neutralizing antibodies (NAb) on day 30 and day 90. However, the BNT162b2 booster is associated with a much higher proportion of positive NAb against the Omicron variant. Only 8% of day 30 and day 90 samples post CoronaVac booster have NAb against the Omicron variant. In addition, more BNT162b2 booster recipients are having positive T-cell responses using interferon gamma release assay. In places using inactivated virus vaccine as the primary two-dose scheme, the heterologous mRNA vaccine booster is safe and more immunogenic against the Omicron variant and should be considered as a preferred option during the current outbreak.

Phase I, randomized, double-blind, single-dose study to assess the pharmacokinetics, safety, and immunogenicity of the proposed biosimilar SCT630 and adalimumab in healthy Chinese subjects

We aimed to compare the pharmacokinetics, safety, and immunogenicity of the adalimumab biosimilar SCT630 with those of its reference (adalimumab, Humira®). This study involved a randomized, double-blind, parallel-controlled design; healthy subjects (N = 146) were randomly distributed into two groups to receive a single-dose subcutaneous injection of 40 mg SCT630 or 40 mg adalimumab, with a 71-day follow up. The bioequivalence of the primary pharmacokinetic parameters (AUC0-t) and maximum observed serum concentration (Cmax) between SCT630 and adalimumab were the primary endpoints; safety and immunogenicity of SCT630 compared with those of adalimumab were the secondary endpoints. The geometric mean Cmax ratio of SCT630 to adalimumab and its 90% confidence interval (CI) were 116.02% and 108.66%–123.88%, AUC0-t ratio and 90% CI were 109.47% and 99.80%–120.08%, and AUC0-∞ ratio and 90% CI were 109.24% and 99.80%–120.78%. These PK parameters fulfilled the equivalence criterion of 80.00%–125.00%. Treatment-emergent adverse events (TEAEs) occurred in 62 (84.9%) and 61 (83.6%) subjects; mild and moderate drug-related TEAEs were observed in 60 (82.2%) and 59 (80.8%) subjects in the adalimumab and SCT630 groups, respectively. On day 71, 69 (95.8%) subjects in the adalimumab group and 66 (93%) in the SCT630 group reported positive anti-drug antibodies. Among them, 15 (21.7%) and 11 (16.7%) subjects showed positive neutralizing antibodies, with no significant difference. SCT630 was well tolerated and demonstrated PK and safety profiles similar to adalimumab. The profiles support the initiation of further confirmatory study to demonstrate the clinical similarity of SCT630 to adalimumab.

Effect of an exercise bout before the booster dose of an inactivated SARS-CoV-2 vaccine on immunogenicity in immunocompromised patients.

This randomized controlled study aimed to investigate whether a single bout of exercise before the homologous booster dose of a SARS-CoV-2 inactivated vaccine could enhance immunogenicity in patients with spondyloarthritis. We selected 60 consecutive patients with spondyloarthritis (SpA). Patients assigned to the intervention group performed an exercise bout comprising three exercises. Then, they remained at rest for 1 h before vaccination. The control group remained at rest before vaccination. Immunogenicity was assessed before (Pre) and 1 mo after (Post) the booster using seropositivity rates of total anti-SARS-CoV-2 S1/S2 IgG, geometric mean titers of anti-S1/S2 IgG (GMT), frequency of neutralizing antibodies (NAb) positivity, and NAb activity. At Pre, 16 patients from the exercise group and 16 patients from the control group exhibited seropositivity for IgG (59% vs. 57.1%), and 1 mo after the booster dose, seropositivity occurred in 96% versus 100% of the cases. Only 10 patients from the exercise group and 12 patients from the control group showed positive NAb serology at Pre (37% vs. 42.8%). One month following the booster, NAb positivity was 96% versus 93%. GMT was comparable between groups at Pre. At Post, GMT increased similarly in both groups. Likewise, NAb activity was similar between groups at Pre and increased similarly in both of them as a result of the booster (47.5% vs. 39.9%). In conclusion, a single bout of exercise did not enhance immunogenicity to a homologous booster dose of an inactivated SARS-CoV-2 vaccine among patients with spondyloarthritis.NEW & NOTEWORTHY We tested the role of exercise as an adjuvant to a booster of a COVID-19 vaccine. Immunocompromised patients were immunized after an acute bout of exercise or not. Patients exhibited an excellent immunogenicity in response to the booster dose. Exercise did not add to the vaccine effects on IgG or neutralizing antibodies.

Immunogenicity and safety of inactivated and mRNA COVID-19 vaccines in patients with systemic lupus erythematosus.

Objective:To evaluate the effects and side effects of both inactivated and mRNA COVID-19 vaccines in patients with systemic lupus erythematosus (SLE).Methods:This was a prospective, single-center, observational study. Patients with SLE planning to receive COVID-19 vaccines were recruited and matched 1:1 with healthy controls. The immunogenicity of the COVID-19 vaccines was assessed by a surrogate neutralization assay at 28 days after the second dose. The main outcome was the antibody response comparing SLE patients and controls. Other outcomes included reactogenicity, disease activity and predictors of antibody responses in patients with SLE.Results:Sixty-five SLE patients received 2 doses of COVID-19 vaccines (Comirnaty: 38; CoronaVac: 27) were recruited. Many of them were on systemic glucocorticoids (76%) and immunosuppressants (55%). At day 28 after the second dose of vaccines, 92% (Comirnaty: 100% vs CoronaVac: 82%, p = 0.01) of the patients had positive neutralizing antibody. However, compared to the age, gender, vaccine type matched controls, the level of neutralizing antibody was significantly lower (p < 0.001). The self-reported adverse reactions after vaccines in lupus patients were common but mild, and were more frequent in the Comirnaty group. There was no significant change in lupus disease activity up to 28 days after vaccination. The independent predictors of neutralizing antibody level included the dosage of systemic glucocorticoids, use of mycophenolate and type of vaccines.Conclusions:COVID-19 vaccines produced satisfactory but impaired humoral response in SLE patients compared to controls which was dependent on the immunosuppressive medications use and type of vaccines received. There was no new short-term safety signal noted. Booster dose is encouraged.

IMMUNOGENICITY AND SAFETY OF INACTIVATED SARS-COV-2 VACCINE (VERO CELL), BBIBP-CORV (SINOPHARM); AN OBSERVATIONAL STUDY FROM PAKISTAN

Objective: To ascertain the immunogenicity and short-term safety of inactivated SARS-CoV-2 Vaccine (Vero Cell), BBIBPCorV (Sinopharm) in our setup.&#x0D; Study Design: Cross-sectional study.&#x0D; Place and Duration of Study: Combined Military Hospital Sialkot Pakistan, from Feb to Apr 2021.&#x0D; Methodology: A total of 227 health care workers (HCWs) between 18 to 59 years of age were included in the study. Two doses of Inactivated SARS-CoV-2 Vaccine (Vero Cell), BBIBP-CorV were administered to all individuals 21 days apart and they were monitored for any vaccine-related adverse reactions for 7 days after each dose. Neutralizing antibodies (NAbs) in study subjects were detected in three samples i.e. before 1st dose of vaccine, 21 days after 1st dose and 14 days after 2nd dose by Elecsys Anti- SARS-CoV-2 S (Roche Diagnostics).&#x0D; Results: Mean age of individuals in the study was 36.70 ± 18.08 years and most individuals were in the 31-45 years age group. Fatigue and drowsiness were the most common adverse effects experienced by study subjects after 1st and 2nd dose of the vaccine followed by malaise and headache. Only 42 (39%) individuals developed positive neutralizing antibody titers in a sample taken 21 days after 1st dose while all individuals except one (99%) developed positive neutralizing antibody titers in a sample taken 2 weeks after 2nd vaccine dose.&#x0D; Conclusion: Inactivated SARS-CoV-2 Vaccine (Vero Cell), BBIBP-CorV is safe and well-tolerated with very few adverse reactions. Immunogenicity was well achieved as the seroconversion rate was 99% two weeks after 2nd dose of the vaccine.