Post-vaccination Antibody Levels Research Articles

Factors impacting antibody kinetics, including fever and vaccination intervals, in SARS-CoV-2-naïve adults receiving the first four mRNA COVID-19 vaccine doses

To evaluate the antibody response following the initial four doses of mRNA vaccines (BNT162b2 or mRNA-1273) in SARS-CoV-2-naïve healthy adults and investigate factors influencing antibody titer increases, this prospective cohort study was conducted in Japan from March 2021. The study included participants who received either the 1st and 2nd doses (n = 467), 3rd dose (n = 157), or 4th dose (n = 89). Blood samples were collected before and up to 6 months after each dose, and anti-receptor-binding domain antibody levels were measured. Multivariate analysis (usin multiple linear regression or linear mixed models) revealed several factors significantly associated with higher post-vaccination antibody levels, including mRNA-1273 vaccine (after the 1st and 2nd dose), male gender (after the 3rd and 4th doses), younger age (after the 1st and 2nd dose), non-smoking status (after the 2nd dose), non-use of immunosuppressive agents (after the 1st dose), higher pre-vaccination antibody titers (after the 2nd, 3rd, and 4th doses), and higher post-vaccination fever (after the 2nd and 4th doses). Furthermore, longer intervals since the last dose were significantly associated with higher antibody levels after the 3rd and 4th doses. These findings provide valuable insights for optimizing vaccination strategies.

Effect of dexamethasone on antibody response of horses to vaccination with a combined equine influenza virus and equine herpesvirus-1 vaccine.

Dexamethasone is routinely administered to horses but its effect on the antibody response to a commercial EIV/EHV vaccine is unclear. Horses receiving dexamethasone will have lower postvaccination antibody levels against EIV and EHV-1 than vaccinated controls. Fifty-five healthy adult research horses. Randomized cohort study. Control (no vaccine, group 1), vaccination only (EIV/EHV-1/EHV-4, Prestige 2, Merck Animal Health, group 2), vaccination and concurrent single intravenous dose of dexamethasone (approximately .05 mg/kg, group 3), vaccination and 3 intravenous doses of dexamethasone at 24 hours intervals (group 4). Serum SAA levels were measured on day 1 and day 3. Antibody levels against EIV (hemagglutination inhibition assay, Kentucky 2014 antigen) and EHV-1 (multiplex ELISA targeting total IgG and IgG 4/7) were measured on day 1 and day 30. Significantly increased mean antibody titers after vaccination were only noted against EIV and only after the vaccination alone (n = 14, prevaccine mean [prvm] 166.9, SD 259.6, 95% CI 16.95-316.8; postvaccine mean [povm] 249.1, SD 257.2, 95% confidence interval [CI] 100.6-397.6, P = .02) and the single dose dexamethasone (n = 14, prvm 93.14, SD 72.2, CI 51.45-134.8; povm 185.1, SD 118, CI 116.7-253.6, P = .01), but not after multiple doses of dexamethasone (n = 14, prvm 194.3, SD 258.3, CI 45.16-343.4; povm 240.0, SD 235.7, CI 103.9-376.1, P > .05). The effect of dexamethasone on the postvaccine antibody response varies depending on the dosing frequency and the antigen-specific antibody type.

Reinfection rates, change in antibody titers and adverse events after COVID-19 vaccination among patients previously infected with COVID-19 in Metro Manila, Philippines: a secondary analysis of a completed cohort study

BackgroundVariation in immune response to COVID-19 vaccines is observed among different ethnicities. We aimed to describe the reinfection rates, change in antibody titers, and adverse events among Filipinos.MethodsThis is a secondary analysis of a cohort study of 307 participants within one year of having COVID-19 infection. We measured COVID-19 antibody levels at pre-determined timepoints (Days 21, 90, 180, 270, and 360 from initial infection). We monitored for COVID-19 symptoms and obtained details on COVID-19 vaccination. An adjudication committee classified the participants as probable, possible, or unlikely COVID-19 reinfection. We determined the probable reinfection rate, adverse events, and the geometric mean titer (GMT) ratio of pre- and post-vaccination antibody levels according to type and brand of COVID-19 vaccine.ResultsAt the end of the follow-up period, 287 (93.5%) out of 307 study participants were fully vaccinated, 1 was partially vaccinated (0.3%), and 19 were unvaccinated (6.2%). Among the fully vaccinated participants, those given mRNA vaccines had the lowest reinfection rate (19.2 cases/100 person-years, 95% CI 9.6, 38.4), followed by viral vector vaccines (29.8 cases/100 person-years, 95% CI 16.9, 52.4). We observed the highest reinfection rate among those given inactivated virus vaccines (32.7 cases/100 person-years, 95% CI 23.6, 45.3). The reinfection rate was 8.6 cases/100 person-years (95% CI 4.1, 17.9) for unvaccinated participants and 3.6 cases/100 person-years (95% CI 0.5, 25.3) for partially vaccinated participants. We observed the largest rise in antibody titers among those given mRNA vaccines (GMT ratio 288.5), and the smallest rise among those given inactivated virus vaccines (GMT ratio 16.7). We observed the highest percentage of adverse events following immunization with viral vector vaccines (63.8%), followed by mRNA vaccines (62.7%), and the lowest for inactivated virus vaccines (34.7%). No serious adverse events were reported.ConclusionVaccinees given the mRNA vaccines had the lowest reinfection rate and the highest rise in antibody titers. Vaccinees given inactivated virus vaccines had the highest reinfection rate, smallest rise in antibody titers, and lowest percentage of adverse events. The small sample size and imbalanced distribution of the type of vaccines received limits the external generalizability of our results.Study RegistrationThe cohort study was registered at the Philippine Health Research Registry on December 14, 2020 (PHRR201214-003199).

Serologic immunogenicity and safety of Herpes Zoster subunit vaccine in patients with Rheumatoid Arthritis receiving Janus Kinase inhibitors.

Patients with rheumatoid arthritis (RA) treated with Janus Kinase inhibitors (JAKi) are at increased risk of Herpes Zoster (HZ). The objective of this study was to investigate serological immunogenicity and safety of the HZ subunit (HZ/su) vaccine in RA patients treated with JAKi, for which little is known. RA patients treated with JAKi (n = 82) at the Department of Rheumatology, Skåne University Hospital, Sweden, and healthy controls (n = 51) received two doses of the HZ/su vaccine (Shingrix). Vaccine-specific antibody responses were analysed using indirect enzyme-linked immunosorbent assay (ELISA). Post-vaccination antibody levels were compared between patients and controls using analysis of covariance. Potential predictors for vaccine response were investigated using a multivariable linear regression analysis. Self-reported adverse events (AEs) and changes in RA disease activity were analysed. Following vaccination, vaccine-specific antibody levels increased significantly in both patients and controls (p< 0.0001). 80.5% of patients and 98.0% of controls achieved a ≥ 4-fold increase in antibody levels. Post-vaccination antibody levels were lower in patients than controls (ratio 0.44, 95% CI 0.31-0.63), and lower in patients receiving JAKi+Methotrexate than JAKi monotherapy (ratio 0.43, 95% CI 0.24-0.79). AEs, mostly mild/moderate, were common. One patient developed HZ and six patients (6.5%) had increased RA disease activity following vaccination. The HZ/su vaccine was serologically immunogenic in most RA patients treated with JAKi. Moreover, the vaccine had an acceptable safety profile. These results support recommendations for usage of the HZ/su vaccine in this vulnerable population. ClinicalTrials.gov, https://clinicaltrials.gov, NCT03886038.

Sleep Quality Affects Humoral Response in Recipients of Two-Dose Sinovac Vaccines

To curb the COVID-19 pandemic, the government distributed Sinovac vaccines. Sleep mediates immune function, including post-vaccination antibody response. This study aimed to analyze whether there was a difference in post-vaccination antibody levels in Sinovac vaccine recipients with poor and good sleep quality. This study used analytical observations of recipients of the two-dose Sinovac vaccine in 2021. Primary data included age, sex, the Pittsburgh Sleep Quality Index (PSQI) questionnaire, and post-vaccination IgG-SARS-CoV-2 antibody levels. The PSQI and IgG SARS-CoV-2 antibody levels were measured a month after the second vaccination. Participants with non-reactive antibody levels before the first vaccination were included, and participants with incomplete data were excluded. The Mann-Whitney test was used to look for associations between sleep quality and post-vaccination IgG SARS-CoV-2 levels. Univariate analysis showed that of 54 participants, 37 (68.5%) were male, and 28 (51.9%) had poor sleep quality. 15 participants (27.78%) were in the 36-45 age group, and median antibody levels in participants who received the second Sinovac Vaccine was 223.5 (199.01) units/mL. Post-vaccination IgG SARS-CoV-2 antibody levels were significantly associated with sleep quality (p=0.036).

Serological response to vaccination in post-acute sequelae of COVID

BackgroundIndividuals with post-acute sequelae of COVID (PASC) may have a persistence in immune activation that differentiates them from individuals who have recovered from COVID without clinical sequelae. To investigate how humoral immune activation may vary in this regard, we compared patterns of vaccine-provoked serological response in patients with PASC compared to individuals recovered from prior COVID without PASC.MethodsWe prospectively studied 245 adults clinically diagnosed with PASC and 86 adults successfully recovered from prior COVID. All participants had measures of humoral immunity to SARS-CoV-2 assayed before or after receiving their first-ever administration of COVID vaccination (either single-dose or two-dose regimen), including anti-spike (IgG-S and IgM-S) and anti-nucleocapsid (IgG-N) antibodies as well as IgG-S angiotensin-converting enzyme 2 (ACE2) binding levels. We used unadjusted and multivariable-adjusted regression analyses to examine the association of PASC compared to COVID-recovered status with post-vaccination measures of humoral immunity.ResultsIndividuals with PASC mounted consistently higher post-vaccination IgG-S antibody levels when compared to COVID-recovered (median log IgG-S 3.98 versus 3.74, P < 0.001), with similar results seen for ACE2 binding levels (median 99.1 versus 98.2, P = 0.044). The post-vaccination IgM-S response in PASC was attenuated but persistently unchanged over time (P = 0.33), compared to in COVID recovery wherein the IgM-S response expectedly decreased over time (P = 0.002). Findings remained consistent when accounting for demographic and clinical variables including indices of index infection severity and comorbidity burden.ConclusionWe found evidence of aberrant immune response distinguishing PASC from recovered COVID. This aberrancy is marked by excess IgG-S activation and ACE2 binding along with findings consistent with a delayed or dysfunctional immunoglobulin class switching, all of which is unmasked by vaccine provocation. These results suggest that measures of aberrant immune response may offer promise as tools for diagnosing and distinguishing PASC from non-PASC phenotypes, in addition to serving as potential targets for intervention.

Post-vaccination serum cytokines levels correlate with breakthrough influenza infections

Post-vaccination cytokine levels from 256 young adults who subsequently suffered breakthrough influenza infections were compared with matched controls. Modulation within the immune system is important for eliciting a protective response, and the optimal response differs according to vaccine formulation and delivery. For both inactivated influenza vaccine (IIV) and live attenuated influenza vaccines (LAIV) lower levels of IL-8 were observed in post-vaccination sera. Post-vaccination antibody levels were higher and IFN-γ levels were lower in IIV sera compared to LAIV sera. Subjects who suffered breakthrough infections after IIV vaccination had higher levels of sCD25 compared to the control group. There were differences in LAIV post-vaccination interleukin levels for subjects who subsequently suffered breakthrough infections, but these differences were masked in subjects who received concomitant vaccines. Wide variances, sex-based differences and confounders such as concomitant vaccines thwart the establishment of specific cytokine responses as a correlate of protection, but our results provide real world evidence that the status of the immune system following vaccination is important for successful vaccination and subsequent protection against disease.

The Impact of Sputnik SARS-CoV-2 Vaccines on Antibody Response in the Egyptian Population

BACKGROUND: The coronavirus disease 2019 (COVID-2019) causes the severe contagious acute respiratory syndrome. Therefore, massive vaccination campaign is mandatory to control the spread. Sputnik COVID-19 vaccines induce immunity through different mechanisms involving antibody response that bind to the spike protein to neutralize the viral entry into the cells. AIM: This study aims to compare the titers of specific antibodies in the pre- and post-vaccination sera in the vaccinated Egyptian population to evaluate the efficacy of the sputnik vaccine. METHODS: Samples were collected from 205 adult volunteers receiving the Sputnik vaccine in the Reference Laboratory of Egyptian University Hospitals. Samples were collected before vaccination and within 1, 2, or 3 months after receiving two doses of Sputnik SARS-CoV-2 vaccines from August to October 2021, serum samples collected were tested by quantitative chemiluminescent immunoassay using (Mindray CL-960i chemiluminescence analyzer, India) at the Reference laboratory of Egyptian University Hospitals for neutralizing antibodies, anti-spike antibodies, and total antibody levels before and after vaccination. RESULTS: The results of the 205 paired samples illustrated that there was a statistically significant difference between pre- and post-vaccination antibody levels with a p-value of (&lt; 0.001) indicating that the vaccine produced significantly high levels of antibodies. CONCLUSION: COVID-19 Sputnik vaccines induce immunity through an antibody response that binds to the virus to neutralize its entry into cells. Our study showed a significant increase in the measured post-vaccination levels of the three antibodies among the enrolled volunteers compared to the basal pre-vaccination level and thus sputnik vaccine protects against SARS-CoV-2 infections.

Immunogenicity evaluation of Gam-COVID-Vac (Sputnik V)

In November 2020, the Armed Forces of the Russian Federation began mass immunisation of the personnel with Gam-COVID-Vac (Sputnik V), the first Russia vaccine against the new coronavirus infection (COVID-19). Thus, it became necessary to assess post-vaccination antibody levels and the duration and intensity of humoral immunity to COVID-19.The aim of the study was to investigate the immunogenicity and efficacy of Gam-COVID-Vac in military medical staff after vaccination.Materials and methods: the authors determined the presence of specific antibodies in the serum of individuals immunised with Gam-COVID-Vac (477 volunteers) and COVID-19 convalescents (73 patients), using virus neutralisation (VN), enzyme-linked immunosorbent assay (ELISA) with reagent kits by several manufacturers, and immunoblotting. The results of the study were evaluated using analysis of variance.Results: VN detected virus neutralising antibodies in 90.7% of vaccinated subjects; ELISA, in 95.4%. Both VN and ELISA showed lower antibody levels in the vaccinated over 50 years of age. ELISA demonstrated a significantly higher concentration of anti-SARS-CoV-2 spike IgG in the Gam-COVID-Vac group than in the COVID-19 convalescent group. The correlation between antibody detection results by VN and ELISA was the strongest when the authors used their experimental reagent kit for quantitative detection of virus neutralising antibodies by competitive ELISA with the recombinant human ACE2 receptor. Having analysed the time course of neutralising antibody titres, the authors noted a significant, more than two-fold decrease in geometric means of the titres three months after administration of the second vaccine component.Conclusions: the subjects vaccinated with Gam-COVID-Vac gain effective humoral immunity to COVID-19. The decrease in titres indicates the need for revaccination in 6 months.

Post-vaccine immunity against hepatitis B in Moroccan children

Background: Hepatitis B is a major public health issue worldwide. Immunization of infants against this disease has been effective in Morocco since 1999. However, evaluation of post-vaccination response is rarely performed in our setting. The purpose of this study was to evaluate immunity against HBV in fully vaccinated children in the city of Marrakech in Morocco and to investigate the factors influencing the level of post-vaccination immunity. Methods: A descriptive cross-sectional study was conducted on fully vaccinated children who have medical and vaccination records, from three primary healthcare centers in Marrakech. Children with anti-HBs antibody levels between 10 and 100 IU/L were considered moderately immune, and those with antibody levels above 100 IU/L as highly immune, while those with antibody levels below 10 IU/L were considered non-immune. Results: Of the 123 children recruited, 114 (92.7%) had protective anti-HBs antibody titers, of which 37 (30%) were moderately immunized and 77 (62.7%) were highly immunized, and nine (7.3%) were non-immune. Age, birth weight, vaccine type, and time since the previous dose have all been significantly associated with the degree of post-vaccination immunity. Anti-HBs antibody levels were not significantly related to factors potentially linked to post-vaccination non-response, such as chronic disease, immunosuppressive medication and others. Conclusion: Our findings denote that the HBV vaccine used in The Moroccan Expanded Program on Immunization (EPI) is effective against HBV. Nevertheless, in non-responders, corrective actions such as re-vaccination and monitoring of post-vaccination anti-HBs antibody levels should be implemented.

Correlation between Adverse Events and Antibody Titers among Healthcare Workers Vaccinated with BNT162b2 mRNA COVID-19 Vaccine.

Objectives: The BNT162b2 mRNA COVID-19 vaccine has been found to be highly effective in preventing COVID-19 but is associated with increased reactogenicity. We aimed to examine the correlation between immunogenicity and reactogenicity of the BNT162b2 vaccine. Methods: Subjects without prior SARS-CoV-2 infection that participated in active surveillance after being vaccinated with the BNT162b2 vaccine were included. Study participants reported adverse drug reactions (ADRs) through questionnaires administered by text message after receiving each dose of the vaccine. A reactogenicity score was developed based on the type and duration of ADRs. In addition, anti-receptor binding domain (RBD) levels and neutralization assays were performed 7–21 and 7–38 days after the first and second vaccine doses, respectively. Associations between ADRs and antibody levels were assessed by Spearman correlations. Multivariable logistic regression analyses were used to identify factors associated with ADRs. Results: A total of 831 health care workers were included. The mean age was 46.5 years (SD = 11.8) and 75.5% were females. 83.4% and 83.3% had at least one local ADR after the first and second doses, respectively. 33% and 83.2% had at least one systemic ADR after the first and second doses, respectively. Multivariate logistic regression analysis found a significant correlation between ADR score and anti-RBD-IgG titers (r = 0.366; p < 0.0001) after adjustment for age, gender, and days after the second vaccination. High anti-RBD-IgG levels, being younger than 55 and being female, were all correlated with increased rates of ADRs. Conclusion: BNT162b2 mRNA COVID-19 vaccine reactogenicity appears to be correlated with higher post-vaccination antibody levels and is independently associated with younger age and female gender.

Relationship between T-cell-dependent and T-cell-independent vaccines after neurotrauma; is the B-cell response preserved?

ABSTRACT Background After trauma and central nervous system (CNS) injury, trauma-induced immune deficiency syndrome (TIDS) and CNS injury-induced immune deficiency syndrome (CIDS) may negatively affect responses to T-cell-dependent vaccines, such as pneumococcal conjugate vaccine (PCV) recommended after basilar fracture. This study (NCT02806284) aimed to investigate whether there after neurotrauma is a correlation between T-cell-dependent and independent vaccine responses and, thus, if B-cell activity is similarly depressed and whether the T-cell-dependent response is possible to predict. Methods Adult patients with basilar fracture (n = 33) and those undergoing pituitary gland surgery (n = 23) were within 10 days vaccinated with a T-cell-dependent vaccine against Haemophilus influenzae type b (Hib) and a T-cell-independent pneumococcal polysaccharide vaccine (PPSV). Samples reflecting the systemic inflammatory response and pre- and post-vaccination antibody levels after 3–6 weeks against Hib and PPSV were collected and determined by enzyme immunoassays. Results High and significant correlations were detected in the responses to different pneumococcal serotypes, but none between the Hib and PPSV responses. No differences in trauma scores, C-reactive protein, IL-6, IL-10, pentraxin 3, fractalkine or calprotectin plasma concentrations or in ex vivo TNF-α, IL-6 or IL-10 responses to endotoxin were found between Hib vaccination responders and non-responders. Conclusions There was no correlation between the pneumococcal responses and that to Hib, indicating that B-cell function is not similarly depressed as T-cell function. Grading of the trauma or parameters reflecting the innate immune response could not predict the T-cell-dependent vaccine response. There is a need of further studies evaluating the vaccine response after neurotrauma.

Approaches to vaccination against the new coronavirus infection in solid organ recipients

Solid organ recipients represent a high risk group for all adverse outcomes associated with SARS-CoV-2 infection due to the immunosuppressive treatment and the presence of comorbidities such as cardiovascular disease, diabetes mellitus, and arterial hypertension.The aim of the study was to assess the ability of solid organ recipients to form immune response after vaccination against a new coronavirus infection and safety of the vaccines in this population.Conclusion. An analysis of the literature and the results obtained in Russia show that vaccines against SARS-CoV-2 do not cause unusual clinical events in recipients of solid organs. Levels of post-vaccination antibodies in these patients, especially in the elderly patients shortly after transplantation who take antimetabolites, are lower than in the general population. This group of patients needs alternative immunization schemes against the new coronavirus infection, which may include more than two booster doses or a combination of different types of vaccines, as well as doubling the vaccine dose.

The humoral response to SARS-COV-2 vaccines in MS patients: A case series exploring the impact of DMT, lymphocyte count, immunoglobulins, and vaccine type

Background & ObjectivesCertain disease modifying therapies may negatively impact the humoral response to SARS-CoV-2 vaccines. Many MS related clinical, demographic, and immunological characteristics can also affect vaccine response but those have not been fully explored. This study aimed to investigate potential correlations between clinical, demographic, and immunological variables in MS patients to post-vaccination spike protein antibody positivity rates and levels. MethodsPatients with MS and related neuroimmunological disorders who requested verification of the immune response to the SARS-COV-2 vaccine were tested for the spike protein antibody from January to October 2021. We performed an exploratory analysis to compare patients with positive versus negative spike protein antibody. ResultsFifty patients (mean age 53 ±12, 78% females) were included. There were 29 patients with positive post-vaccination spike protein antibody (58%) and 21 with negative antibody (42%). Patients with negative antibody were more likely to have been on B-cell therapy (86% vs 31%, P=.001) while positive patients were more likely to have been on a fumarate (31% vs 4.8%, P=.03). Thirty percent of positive patients on fumarate therapy had mild lymphopenia. No differences existed between groups in gender, age, race, disease phenotype, vaccine brand, and lymphocyte counts. Among patients on B-cell therapy, 33% had a positive spike protein antibody. There was an association between detectable CD19 cells at time of vaccination and positive humoral response to vaccination (P=0.049). There was no relationship between subgroups in terms of vaccine timing relative to B-cell therapy dose. Hypogammaglobulinemia was not associated with seroconversion rates, however it was associated with decreased quantitative spike protein antibody levels (p=0.045). DiscussionB-cell therapy is associated with a negative humoral response to SARS-COV-2 vaccines. Patients on B-cell depleting therapy with detectable CD19 counts at the time of vaccination were associated with a positive humoral response. There was no relationship between hypogammaglobinemia and seroconversion rate, however it was associated with decreased spike protein antibody levels. The fumarates are associated with positive humoral response even in the presence of mild lymphopenia.

Fever after Vaccination against SARS-CoV-2 with mRNA-Based Vaccine Associated with Higher Antibody Levels during 6 Months Follow-Up.

Background: The effect of post-vaccination adverse events on immunogenicity is unknown. We aimed to explore relationship between post-vaccination adverse reactions and antibody levels during 6-month follow-up. Methods: Blood was serially drawn from healthcare workers after the second dose of BNT162b2 mRNA vaccine (Day 12, 30, 60, 90, 120, 150, and 180) and anti-SARS-CoV-2 spike IgG (S-IgG) levels were measured. Following each vaccine dose, volunteers completed a questionnaire regarding adverse reactions (symptomatic vs. asymptomatic groups). Results: A total of 395 subjects received the second dose of the vaccine. The main results were as follows: (i) fever after the 2nd dose was independently associated with the median S-IgG level at all follow-up time points; (ii) significantly higher S-IgG levels were observed in the symptomatic group of patients without prior COVID-19 infection throughout the entire follow-up period; (iii) prior COVID-19 positivity resulted in higher S-IgG levels only in the asymptomatic group from Day 90 of the follow-up period; (iv) both prior COVID-19 disease with asymptomatic status and symptomatic status without prior COVID-19 infection resulted in similar S-IgG antibody levels; (v) significantly lower serum S-IgG levels were observed in smokers. Conclusion: Fever may play an important role in the post-vaccination immune response in the long term.

Antibody responses after two doses of CoronaVac of the participants with or without the diagnosis of COVID-19

BackgroundCoronaVac, an inactivated whole-virion vaccine against COVID-19, has been shown to be safe with acceptable antibody responses by various clinical trials.AimsThe objective was to investigate the post-vaccination antibody levels of both symptomatic and asymptomatic healthcare workers with or without the diagnosis of COVID-19 in an emergency department (ED) of a hospital serving as a pandemic hospital.MethodsThis single-centred, prospective study was conducted on 86 participants who were working as nurse or doctor in the ED. The volunteers were older than 18 years and either positive or negative for either computed tomography (CT), real-time reverse transcription polymerase chain reaction (qRT-PCR), or both. Thirty days after the second dose of CoronaVac (3 µg), the antibody levels were chemiluminescent microparticle immunoassay.ResultsMean age of all participants were 33.1 ± 9.1 years. The antibody levels in the qRT-PCR( +) and CT( +) groups were significantly higher than the qRT-PCR( −) and CT( −) groups, respectively (p < 0.05). In the CT( +)/qRT-PCR( +) group, the antibody level was significantly higher than the CT( −)/qRT-PCR( −) and CT( −)/qRT-PCR( +) or CT( +)/qRT-PCR( −) group (p < 0.05). On the other hand, antibody levels in the hospitalized group were significantly higher than in the non-hospitalized group (p < 0.05). A significant positive correlation was observed between the time elapsed after vaccination and antibody levels of the participants (r = 0.343; p = 0.000).ConclusionIn conclusion, antibody responses of recovered patients COVID-19 diagnosed by both CT and qRT-PCR were much robust than the patients diagnosed by either one of the techniques or undiagnosed/disease-free participants suggesting that severity of the disease likely contributes to the antibody responses after vaccination with CoronaVac.

Seasonal Betacoronavirus Antibodies\u2019 Expansion Post-BNT161b2 Vaccination Associates with Reduced SARS-CoV-2 VoC Neutralization

SARS-CoV-2 vaccination is known to induce antibodies that recognize also variants of concerns (VoCs) of the virus. However, epidemiological and laboratory evidences indicate that these antibodies have a reduced neutralization ability against VoCs. We studied binding and neutralizing antibodies against the Spike protein domains and subunits of the Wuhan-Hu-1 virus and its alpha, beta, delta VoCs and of seasonal betacoronaviruses (HKU1 and OC43) in a cohort of 31 health care workers prospectively followed post-vaccination with BNT162b2-Comirnaty. The study of sequential samples collected up to 64 days post-vaccination showed that serological assays measuring IgG against Wuhan-Hu-1 antigens were a poor proxy for VoC neutralization. In addition, in subjects who had asymptomatic or mild COVID-19 prior to vaccination, the loss of nAbs following disease could be rapid and accompanied by post-vaccination antibody levels similar to those of naïve vaccinees. Interestingly, in health care workers naïve for SARS-CoV-2 infection, vaccination induced a rapid and transient reactivation of pre-existing seasonal coronaviruses IgG responses that was associated with a subsequent reduced ability to neutralize alpha and beta VoCs.

Immunogenicity of SARS-CoV-2 vaccination in rituximab-treated patients: Effect of timing and immunologic parameters

Rituximab (RTX), an important therapeutic option for patients with rheumatic diseases, has been shown to reduce immune responses to various vaccines. We asked whether following SARS-CoV-2 vaccination, response rates in RTX treated patients are reduced and whether specific patient characteristics influence the responses. We recruited patients on chronic RTX therapy undergoing anti-SARS-CoV2 vaccination and measured the post-vaccination anti-spike IgG antibody levels. The median time from pre-vaccination RTX infusion to vaccination and from vaccination to the post-vaccination RTX infusion was 20.5 weeks and 7.2 weeks respectively. Only 36.5% of patients developed measurable titers of IgG anti-SARS-CoV-2 spike antibody after vaccination. Hypogammaglobulinemia (IgG and/or IgM) but not timing of vaccination, B cell numbers, or concomitant immune suppressive medications, correlated with sero-negativity (p = 0.004). Our results underscore the fact that even after B cell reconstitution, RTX induced chronic hypogammaglobulinemia significantly impairs the ability of the immune system to respond to SARS-CoV-2 vaccination.

Evaluation of antibody response after COVID-19 vaccination of healthcare workers.

The common goal of all vaccines developed against COVID‐19, although they have been designed with different methods, is to develop an effective immunity and antibody response against SARS‐CoV‐2. However, the postvaccination immune response and antibody levels differ between individuals. This study examined the relationship between postvaccine seropositivity rates, age, gender, smoking, and body mass index (BMI), and antibody titers. A total of 314 healthcare workers (HCW) who were not previously infected with COVID‐19 and who had received two doses of CoronaVac inactivated vaccine participated in the study. Seropositivity against the receptor‐binding domain (RBD) of the SARS‐CoV‐2 spike protein was measured from the participants 4 weeks after the second dose of vaccine using the electrochemiluminescence (ECLIA) method. In addition, the antibody developed against the nucleocapsid protein (NCP) was evaluated and compared using Elecsys Anti‐SARS‐CoV‐2 kit. One hundred and eighty‐one of the participants were female (57.6%) with a median age of 39 (interquartile range [IQR], 10) and 133 (42.4%) were male with a median age of 41 (IQR, 11). 99.6% of the volunteers developed seropositivity 4 weeks after the second dose of vaccine. It was also observed that the rate of RBD protein antibody titer was >250 U/ml in smokers, which is quite low compared to nonsmokers (p = 0.032), and that high RBD antibody titers were proportionally lower in obese participants, according to BMI values, compared to those with normal BMI (49.5% and 9.9%). It was observed that seropositivity developed in almost all participants after the CoronaVac vaccine. However, it was determined that the antibody titer measured varied depending on factors such as smoking, BMI, and duration.

Evaluation of the QuantiFERON SARS-CoV-2 assay to assess cellular immunogenicity of the BNT162b2 mRNA COVID-19 vaccine in individuals with low and high humoral response

ABSTRACT Vaccines against SARS-CoV-2 are known to be less immunogenic for some individuals, whereas others present notably high levels of antibody production. We assessed the cellular response to BNT162b2 among individuals with low post-vaccination antibody levels as well as in a small group of individuals with high titers. Antibody levels were assessed by the Abbott SARS-CoV-2 IgG II Quant assay. The interferon-γ production of T-cells in response to SARS-CoV-2 antigens was determined using Qiagen’s QuantiFERON SARS-CoV-2 ELISA test. Our results showed that participants with high antibody levels presented adequate cellular response in all studied cases, whereas those with low antibody levels generally showed limited to almost absent cellular response five months post vaccination.