Immunoglobulin G Antibody Titers Research Articles

Bacterial DNA and serum IgG antibody titer assays for assessing infection of human-pathogenic and dog-pathogenic Porphyromonas species in dogs

Periodontal disease is highly prevalent in both humans and dogs. Although there have been reports of cross-infection of periodontopathic bacteria, methods for assessing it have yet to be established. The actual status of cross-infection remains to be seen. The purpose of this study was to evaluate the utility of bacterial DNA and serum immunoglobulin G (IgG) antibody titer assays to assess infection of human-pathogenic and dog-pathogenic Porphyromonas species in dogs. Four experimental beagles were used for establishing methods. Sixty-six companion dogs at veterinary clinics visiting for treatment and prophylaxis of periodontal disease were used and divided into healthy, gingivitis, and periodontitis groups. Periodontal pathogens such as Porphyromonas gingivalis and Porphyromonas gulae were investigated as target bacteria. DNA levels of both bacteria were measured using species-specific primers designed for real-time polymerase chain reaction (PCR). Serum IgG titers of both bacteria were measured by enzyme-linked immunosorbent assay (ELISA).PCR primers were confirmed to have high sensitivity and specificity. However, there was no relationship between the amount of bacterial DNA and the severity of the periodontal disease. In addition, dogs with periodontitis had higher IgG titers against both bacteria compared to dogs in the healthy and gingivitis groups; there was cross-reactivity between the two bacteria. Receiver operating characteristic (ROC) analysis of IgG titers against both bacteria showed high sensitivity (>90 %) and specificity (>75 %). Since both bacteria were distinguished by DNA assays, the combination of these assays may be useful in the evaluation of cross-infection.

#2547 Humoral response to COVID vaccine and infection is intact during sibeprenlimab treatment of IgAN: data from the ENVISION trial

Abstract Background and Aims In the Phase 2 placebo-controlled ENVISION trial, the APRIL (A Proliferation Inducing Ligand) inhibitor sibeprenlimab significantly decreased proteinuria and stabilized estimated glomerular filtration rate decline in patients with immunoglobulin A nephropathy (IgAN) [1]. A substudy was conducted to evaluate the humoral response to SARS-CoV-2 mRNA vaccination and infection. Here, we report the unblinded analysis of COVID outcomes in the overall and substudy populations of ENVISION. Method Patients enrolled in ENVISION (NCT04287985) received 12 monthly intravenous infusions of sibeprenlimab (2, 4, or 8 mg/kg) or placebo and were followed for 16 months after the first dose of study drug. Recognized COVID infection (reported as an adverse event [AE]) and vaccination data were recorded for all patients. For patients in the substudy, serum antibody responses to SARS-CoV-2 spike and nucleocapsid proteins were measured monthly using a validated Meso Scale Discovery V-PLEX SARS-CoV-2 Panel 24 multiplex assay. Vaccine responses among those who received a primary two-dose mRNA COVID vaccine series, with no recent or concurrent COVID infection, were evaluated. Peak post-vaccine serum SARS-CoV-2 receptor-binding domain (RBD) immunoglobulin G (IgG) titers were reported in World Health Organization binding antibody units (BAU)/mL. Slopes of RBD IgG decline curves were used to generate estimates of time above a protective threshold of 300 BAU/mL. Welch's two-sample t-test was applied to log-transformed peak RBD titers for significance testing. COVID infection–induced antibody responses and severity of COVID symptoms were also assessed. In substudy patients, retrospective serologic diagnosis of COVID infection was established when simultaneous elevation of nucleocapsid and spike antibody titers, unexplained by vaccine history, was observed. Results Among 155 patients who received sibeprenlimab (n = 117) or placebo (n = 38), 56 (36.1%) had COVID infection reported as an AE during the study (Table 1). Overall, proportionally fewer sibeprenlimab recipients (33.3%) had a reported COVID AE compared with placebo recipients (44.7%). Two patients (one each in the sibeprenlimab and placebo groups) were hospitalized with serious COVID AEs in accordance with local management protocols; none were admitted to intensive care or mechanically ventilated and there were no COVID-related deaths. The majority of COVID AEs were of mild severity, regardless of treatment/dosing arm. In the serology substudy (n = 74), symptomatic COVID (reported as an AE) occurred in 47.3% of all patients. With the addition of serologic diagnoses (in the absence of AEs), the overall rate of COVID infection increased to 68.9%. Asymptomatic COVID was identified in 1 of 15 (6.7%) placebo recipients versus 15 of 36 (41.7%) sibeprenlimab recipients, raising the possibility that patients treated with sibeprenlimab may have had attenuated symptom presentation compared with patients who received placebo. COVID seroconversion rates were 100% and peak RBD IgG antibody titers following primary mRNA vaccination exceeded the protective threshold of 300 BAU/mL in all patients (Fig. 1a), with higher geometric mean peak titers in placebo (4670 BAU/mL) compared with sibeprenlimab (1700 BAU/mL) recipients (p = 0.005). The rate of decline of peak RBD IgG titers after mRNA vaccination (in patients with ≥1 dose without confounding subsequent vaccination or infection) was similar between groups (Fig. 1b), with modeled time above the 300 BAU/mL threshold of 192 and 174 days in the sibeprenlimab and placebo groups, respectively. Conclusion COVID-specific antibody responses to vaccination or infection were preserved in patients with IgAN treated with sibeprenlimab. The possibility that COVID symptom presentation may have been modulated by sibeprenlimab warrants further investigation.

Seroprevalence of Measles in Pairs of Mothers and Newborns in Southern Greece.

Maternal immunoglobulin G (IgG) antibodies that are passively transferred to newborns through the placenta confer protection if they are exposed to measles virus. A measles outbreak occurred in several European countries including Greece, between 2016 and 2018. A prospective study was conducted in the General Hospital of Lakonia, regarding the measles seropositivity status of mother and newborn pairs. IgG antibody titer for measles was measured in serum samples acquired from pairs of mothers and newborns. The samples were analyzed through quantitative enzyme-linked immunosorbent assay, and antimeasles IgG >200 IU/mL was considered to be protective. Demographic data for mothers and neonates and data regarding immunization status of mothers were analyzed. Study population included 206 mothers and their newborns. In total, 12.6% of mothers (n = 26) and 10.7% of newborns (n = 22) did not have protective serology. A statistically significant positive linear association between maternal and neonatal antibodies was found (rho = 0.924) (p = 0.001). Neonates whose mothers were seropositive had higher antibodies [geometric mean concentration (GMC): 804.8 (728.3-889.2)] than neonates whose mothers were seronegative/borderline [GMC: 97.7 (64.2-148.8)] (p = 0.001). In the study area, a significant rate of mothers and newborns was found to have nonprotective measles serology that exceeds the limit required for herd immunity. Vaccination coverage in women of reproductive age should be increased to reduce potential for future measles epidemics.

The Effect of Third Dose of Pfizer/BioNTech and Moderna COVID-19 mRNA Vaccines on IgG Antibody Titers.

With the emergence ofsevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, the Centers for Disease Control and Prevention (CDC) authorized the third dose of the Pfizer-BioNTech (BNT162b2) vaccine with the rationale for prolonged elevation of anti-SARS-CoV-2 antibody titers and protection against the SARS-CoV-2 virus. To better understand how administration of the third dose of the Pfizer/BioNTech coronavirus disease 2019 (COVID-19) vaccine affects the incidence and severity of SARS-CoV-2 infections, we administered the third dose of the Pfizer-BioNTech (BNT162b2) to 189 participants. Blood samples were collected from participants during each of their scheduled visits (baseline, week two, week 12, and week 24) and tested for semi-quantitative anti-SARS-CoV-2 immunoglobulin G (IgG) titers. Our results showed that administration of the third dose of the Pfizer-BioNTech (BNT162b2) vaccine elicited elevated anti-SARS-CoV-2 IgG antibodies for the 24-week duration of the study. IgG antibody titers were greatest in week two, and progressively decreased by week 12 and week 24, with statistically significant differences between the IgG antibody titers for eachcollection date.

Trend of SARS-Cov-2-Specific IgG Antibody Titers Among COVID-19 Pneumonia Patients: A Nine-Month Follow-Up.

Introduction Understanding the dynamics of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) spike antibody titers after natural infection is important for understanding immunological memory. This longitudinal study was conducted to assess the trend in serum SARS-CoV-2 IgG spike antibody titers in a cohort of recovered cases up to nine months after SARS infection. Materials and methods We examined the neutralizing antibody response (IgG spike) in serum samples from a cohort of 86 SARS-CoV-2 quantitative polymerase chain reaction (qPCR)-confirmed infection, comprising cases having minor COVID-19 pneumonia and severity, which was determined by CT severity scores. Patients were enrolled in August/September 2020 and serum samples have been processed at one, three, six, and nine months. CT severity scores were rated between 1-25 and antibody titers≥ 1.4 were considered positive. Results The mean anti-SARS-CoV-2-specific IgG antibody titers at one month, three months, six months, and nine months were 22.02 ± 18.36, 14.62 ± 12.61, 8.93 ± 8.10, and 3.86 ± 5.70, respectively. The difference was statistically significant. The seropositivity rates (titer ≥1.4 IU) were 93.02%, 82.56%, 76.74%, and 58.14% at one, three, six, and nine months after infection, respectively. Cases with severe CT severity scores showed significantly higher mean antibody levels at all follow-up visits.

COVID-19 Antibody Response in Patients with Thalassemia.

Background The coronavirus disease 2019 (COVID-19) can severely affect people with comorbidities such as those with diabetes, hypertension, chronic lung disease, cancer, and hemoglobinopathies. Studies assessing the clinical characteristics and immune response to COVID-19 infection in patients with thalassemia are limited. Objectives The primary objective of the study was to study the clinical pattern and the immunoglobulin G (IgG) antibody response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with transfusion-dependent thalassemia (TDT) compared to patients without thalassemia. The secondary objective wasto study the relationship of COVID-19 severity with IgG antibody titers. Setting, Design, and Participants This case-control study was conducted at a tertiary care hospital between January 2021 and August 2022. A total of 30 patients with TDT (mean age: 12.7 years, SD: 4.7) and 30 patients without thalassemia (mean age: 13.9years, SD: 7) who tested positive for COVID-19 in the preceding six weeks were recruited. Methods Serum samples from the cases and controls were collected after 6, 12, and 24 weeks of COVID-19 infection for IgG antibody estimation using chemiluminescent immunoassay. Outcome variables The primary variable was comparative analysis of antibody levels and clinical profile of COVID-19 in cases and controls. The secondaryvariable was association of the severity of COVID-19 with the antibody titers produced. Results Symptomatic individuals among cases (n=12) were significantly lesser than controls (n=22) (p=0.009). The median IgG titers of cases and controls were comparable at six weeks (p=0.40), but the titers were significantly lower for cases at 12 weeks (p=0.011) and 24 weeks (p=0.006). There was significant fall in titers from 6 to 12 and 24 weeks in both the groups. The titers were not affected by COVID-19 severity and pre-existing comorbidities. Conclusion Patients with TDT manifest with mild or asymptomatic COVID-19 and mount a comparable IgG antibody response to COVID-19 akin to controls. However, this serological response could not sustain over three to six months advocating the need for protection through vaccination.

Immune response after vaccination using inactivated vaccine for coronavirus disease 2019.

Immune response after vaccination using inactivated vaccine for coronavirus disease 2019.

Anti-SARS-CoV-2 spike immunoglobulinG and immunoglobulinM titers decline as interval from the second inactivated vaccine dose to the onset of illness is prolonged in breakthrough infection patients.

Understanding of the early immune response in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) breakthrough infections is limited. Ninety-eight patients with coronavirus disease 2019 (COVID-19) breakthrough infections were divided into two groups, with intervals from receiving the second dose of inactivated vaccine to the onset of illness <60 or ≥60 days. The median lymphocyte count and the median anti-SARS-CoV-2 spike immunoglobulin G (IgG) and immunoglobulin M (IgM) titers were higher in the <60-day interval group compared with the corresponding medians in the ≥60-day interval group (p = 0.005, p = 0.001, and p = 0.001, respectively). The median interleukin-6 (IL-6) level in the <60-day interval group was significantly lower than the median IL-6 level in the ≥60-day interval group (p < 0.001). Our results highlight the different anti-SARS-CoV-2 spike IgG and IgM antibody titers among patients with different intervals from receiving the second dose of inactivated vaccine to the onset of illness.

Effect of SARS-CoV-2 BNT162b2 mRNA vaccine on thyroid autoimmunity: A twelve-month follow-up study.

Graves' disease (GD) has been highlighted as a possible adverse effect of the respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccine. However, it is unknown if the SARS-CoV-2 vaccine disrupts thyroid autoimmunity. We aimed to present long-term follow-up of thyroid autoimmunity after the SARS-CoV-2 BNT162b2 mRNA vaccine. Serum samples collected from seventy Japanese healthcare workers at baseline, 32 weeks after the second dose (pre-third dose), and 4 weeks after the third dose of the vaccine were analyzed. The time courses of anti-SARS-CoV-2 spike immunoglobulin G (IgG) antibody, thyroid-stimulating hormone receptor antibody (TRAb), and thyroid function were evaluated. Anti-thyroglobulin antibodies (TgAb) and anti-thyroid peroxidase antibodies (TPOAb) were additionally evaluated in thirty-three participants. The median age was 50 (IQR, 38-54) years and 69% were female. The median anti-spike IgG antibody titer was 17627 (IQR, 10898-24175) U/mL 4 weeks after the third dose. The mean TRAb was significantly increased from 0.81 (SD, 0.05) IU/L at baseline to 0.97 (SD, 0.30) IU/L 4 weeks after the third dose without functional changes. An increase in TRAb was positively associated with female sex (β = 0.32, P = 0.008) and low basal FT4 (β = -0.29, P = 0.02) and FT3 (β = -0.33, P = 0.004). TgAb was increased by the third dose. Increase in TgAb was associated with history of the thyroid diseases (β = 0.55, P <0.001). SARS-CoV-2 BNT162b2 mRNA vaccine can disrupt thyroid autoimmunity. Clinicians should consider the possibility that the SARS-CoV-2 vaccine may disrupt thyroid autoimmunity.

Diagnostic Usefulness of Varicella Zoster Virus-Specific Immunoglobulin (Ig) A and IgG in Patients With Herpes Zoster.

Whether varicella zoster virus (VZV) antibody titer could discriminate patients with herpes zoster (HZ) from healthy controls (HCs) is unclear. We evaluated the diagnostic usefulness of VZV-specific immunoglobulin A (IgA) and immunoglobulin G (IgG) antibodies in patients with confirmed HZ. Study subjects comprised patients with confirmed HZ by salivary VZV DNA positivity and control age- and sex-matched HCs. Saliva was collected and concurrent blood samples were obtained on the first visit day (acute phase) and after 4 weeks (convalescent phase) from 44 HZ patients. All 44 healthy volunteers provided blood and saliva samples once. The median VZV IgA titers in acute-phase (5.2 mIU/mL, P < 0.001) and convalescent-phase (15.8 mIU/mL, P < 0.001) serum samples from HZ patients were significantly higher than those in HCs (1.35 mIU/mL). VZV IgA positivity was detected in about 20% of acute phase serum and convalescent-phase serum of HZ patients. The median VZV IgG antibody titers of HZ patients during acute (1,471.0 mIU/mL, P < 0.001) and convalescent (4,934.7 mIU/mL, P < 0.001) phases were significantly higher than the median titer reported for HCs (591.6 mIU/mL). A four-fold or higher increase in VZV IgG antibody titer was observed in 36.4% of HZ patients. VZV IgA positivity or four-fold or higher increase in VZV IgG antibody titers were not detected in a satisfactory proportion of HZ-infected patients. However, the titer of VZV IgA or IgG antibody particularly in convalescent-phase sera may discriminate HZ patients from HCs.

Humoral immunity after second dose of BNT162b2 vaccine in Japanese communities: an observational cross-sectional study, Fukushima Vaccination Community Survey

To reveal waning humoral immunity after second dose BNT162b2 vaccinations in a rural Japanese community and determine factors affecting antibody titers. We aimed to report Immunoglobulin G (IgG) antibody against the SARS-CoV-2 spike (S1) protein levels and neutralizing activity in a large scale community based cohort. Methods: Participants in the observational cross-sectional study received a second dose of vaccination with BNT162b2 (Pfizer/BioNTech) and were not previously infected with COVID-19. Questionnaire-collected data on sex, age, adverse vaccine reactions, and medical history was obtained. Results: Data from 2496 participants revealed that older age groups reached a low antibody titer 90–120 days after the second vaccination. Neutralizing activity decreased with age; 35 (13.3%) of those aged ≥ 80 years had neutralizing activity under the cut-off value. Neutralizing activity > 179 days from the second vaccination was 11.6% compared to that at < 60 days from the second vaccination. Significantly lower IgG antibody titers and neutralizing activity were associated with age, male sex, increased time from second vaccination, smoking, steroids, immunosuppression, and comorbidities. Conclusions: Antibody titer decreased substantially over time. Susceptible populations, older people, men, smokers, steroid users, immunosuppression users, and people with three or more comorbidities may require a special protection strategy.

The Antibody Response to the BNT162b2 mRNA COVID-19 Booster in Healthcare Workers: Association between the IgG Antibody Titers and Anthropometric and Body Composition Parameters

Background: Research shows that in most people, two-dose vaccination helps to shape the humoral response to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Further studies are required to learn about the vaccine’s effectiveness after boosting. Methods: We conducted a prospective study among 103 healthcare workers (HCWs) from a regional multi-specialty hospital vaccinated with three doses of the BNT162b2 vaccine. We compared their immunoglobulin G (IgG) titers 14 days after the second dose with those 21 days after the booster. We also compared their anthropometric and body composition parameters with IgG concentrations at the same time points. Results: Twenty-one days after the booster, all study participants were seropositive. Their mean IgG antibody titers were significantly lower than 14 days after the second dose (158.94 AU/mL ± 90.34 AU/mL vs. 505.79 AU/mL ± 367.16 AU/mL). Post-booster Spearman’s correlation analysis showed a significantly weak correlation between the IgG antibody titer and parameters related to muscle tissue and adipose tissue (including body fat mass). Conclusions: The BNT162b2 booster stimulates the humoral response to a lesser extent than the two-dose BNT162b2 primary vaccination. The adipose and muscle tissue parameters show a weak positive correlation with the SARS-CoV-2 IgG antibody titers.

Understanding the dynamics of IgM & IgG antibodies in COVID-19-positive patients.

The pandemic caused by the SARS-CoV-2 has been a threat to humankind due to the rapid spread of infection and appearance of multiple new variants. In the present study, we report the dynamics and persistence of immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies in asymptomatic and symptomatic COVID-19 patients by chemiluminescent assay. A total of 463 serum samples from 218 SARS-CoV-2 PCR-positive patients were collected over a period of 124 days post-onset of disease (POD). Antibody levels were measured by chemiluminescence bioanalyzer. Neutralizing antibody titres were assessed by plaque reduction neutralization test (PRNT) for SARS-CoV-2. Both IgM and IgG started appearing from day five post-infection in symptomatic and asymptomatic patients. IgM antibody response peaked around day 35 POD and rapidly diminished thereafter, with the last IgM-positive sample observed at 90 days POD. IgG antibody response peaked around 45 days POD and persisted till 124 days. The chemiluminescence immunoassay (CLIA) results showed a moderate correlation (R=0.5846, P<0.001) compared with PRNT. Additional analysis indicated a neutralizing titre of 250 corresponded to 12.948 AU/ml of YHLO iFlash SARS-CoV-2 IgG units. Both symptomatic and asymptomatic COVID-19 patients seem to initiate production of antibody responses from day five of onset of disease. Although the CLIA gives high sensitivity and specificity and also its binding IgG antibody titres may correlate moderately with protective immunity, our results indicate that the values of binding antibody alone may not be a perfect guide to represent virus neutralization titre during donor selection for plasma therapy. However, IgM and IgG antibody detection may help in monitoring the status of disease progression and burden in the community.

Humoral response after SARS-CoV-2 mRNA vaccination in patients with prostate cancer using steroids.

ObjectivesThe effect of concomitant steroid use on the antibody response to a SARS-CoV-2 vaccine in patients with prostate cancer (PC) remains unknown. We aimed to evaluate the rates of antispike immunoglobulin G (IgG) antibody response to the BNT162b2 mRNA vaccine in patients with PC using steroids.MethodsThis cross-sectional study conducted from June 21, 2021 to January 5, 2022 included 215 patients with PC who received the second dose of the BNT162b2 mRNA vaccine at least 7 days before the measurement of titers of IgG antibodies against the receptor-binding domain of SARS-CoV-2 spike (S) protein. We compared the rate of anti-SARS-CoV-2 S IgG ≥15 U/mL between patients with or without concomitant steroid use.ResultsOf 215, we identified 33 patients who had concomitant steroid use. Of these, 12 and 21 patients were metastatic castration-sensitive PC and castration-resistant PC (CRPC), respectively. Patients with concomitant steroid use had a significantly lower rate of antibody titer ≥15 U/mL than those without steroid use (82% vs. 95%, P = 0.021). Patients with CRPC with concomitant steroid use (n =21) also had a lower rate of antibody titer ≥15 U/mL (71%) than those without steroid use (93%, P = 0.051), although this was not statistically different. Increased number of systemic treatments administered after diagnosis of CRPC (3 lines or more) were significantly associated with antibody titers <15 U/mL (97% vs. 77%, P <0.001).ConclusionThe humoral response to the BNT162b2 mRNA vaccine was significantly lower in patients with concomitant steroid use. Anti-SARS-CoV-2 S antibody titers were affected by CRPC status, the accumulation of post-CRPC treatments, and steroid use.

Factors associated with anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein antibody titer and neutralizing activity among healthcare workers following vaccination with the BNT162b2 vaccine.

The purpose of this study was to identify factors associated with the increase in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S1) protein and neutralizing antibody titer following SARS-CoV-2 vaccination. This observational study was conducted among healthcare workers working for a private hospital group in Fukushima Prefecture, Japan. Two blood samples were obtained from each participant. The first sample was obtained before the first dose of BNT162b2 (Pfizer-BioNTech) vaccine, and a second sample was obtained approximately 6 weeks later. Immunoglobulin G (IgG) antibody against the SARS-CoV-2 spike (S1) protein, immunoglobulin M (IgM) antibody against SARS-CoV-2 N-protein, and neutralizing activity were measured using the chemiluminescent immunoassay with iFlash 3000. A total of 231 healthcare workers who agreed to participate, and were negative for anti-SARS-CoV-2 IgM antibodies at enrollment, were included in the analysis. All participants had elevated IgG antibodies and neutralizing activity above the cutoff values. A total of 174 (75.3%) and 208 (90.0%) participants experienced adverse reactions after the first and second vaccine doses, respectively. Younger age, female sex, not taking immunosuppressive or antipyretic analgesic medication regularly, a lack of local adverse reactions after the first dose, and the presence of adverse reactions (fever, muscle, and joint pain) after the second dose were associated with higher IgG antibody titers and neutralizing activity. Intake of analgesic antipyretic for adverse reactions to vaccines was not significantly associated with antibody and neutralizing activity titer production. Immune responses after vaccination may differ among individuals, and continued countermeasures to prevent SARS-CoV-2 infection are vital.

Maternal and Neonatal Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Immunoglobulin G Levels After the Pfizer-BioNTech Booster Dose for Coronavirus Disease 2019 (COVID-19) Vaccination During the Second Trimester of Pregnancy.

To evaluate maternal and neonatal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) antibody levels at birth after a third (booster) dose of the Pfizer-BioNTech messenger RNA (Pfizer) coronavirus disease 2019 (COVID-19) vaccine during the second trimester of pregnancy, and compare them with those in women who received two vaccine doses during the second trimester. We conducted a prospective cohort study of women admitted to the delivery ward at a single center who received the third Pfizer COVID-19 vaccine dose (booster group) at 17-30 weeks of pregnancy and who did not have previous SARS-CoV-2 infection. Maternal and neonatal antibody levels were measured on admission for delivery and in the umbilical cord blood after birth. Antibody levels for the booster group were compared with those in a historical control group of pregnant women who received their second vaccine dose (two-dose group) within the same gestational age window. Between October 2021 and February 2022, antibody levels were measured in 121 women and 109 neonates at a mean±SD of 15.3±3.9 weeks after booster vaccination. Neonatal titers measured two times higher than maternal titers, with inverse correlation between maternal and neonatal titers at birth and time interval from third vaccination. The two-dose group included 121 women and 107 neonates, with antibody levels measured at a mean±SD of 14.6±2.6 weeks after the second dose. Median [interquartile range] maternal antibody titers were higher in the booster group (4,485 [2,569-9,702] AU/mL) compared with the two-dose group (1,122 [735-1,872] AU/mL) (P<.001). Furthermore, neonatal antibody titers were higher in the booster group (8,773 [5,143-18,830] AU/mL) compared with the two-dose group (3,280 [2,087-5,754] AU/mL) (P<.001). Maternal and neonatal SARS-CoV-2 IgG antibody titers after second-trimester maternal Pfizer COVID-19 vaccination were significantly higher after the booster dose compared with the two-dose vaccination series. Although there is uncertainty as to whether antibody levels correlate with protection, these data support the importance of booster vaccination during pregnancy to restore maternal and neonatal protection against COVID-19.

Analysis of clinical characteristics of 362 vaccinated or unvaccinated patients infected by novel coronavirus Omicron variant

To analyze the epidemiological and clinical characteristics of patients infected by novel coronavirus Omicron variant, and also to analyze whether vaccination against novel coronavirus has an impact on the severity and prognosis of Omicron patients. A prospective, single-center observational study was conducted to collect data of consecutive patients with Omicron variant infection admitted to the designated hospital for coronavirus disease 2019 (COVID-19) charged by Tianjin COVID-19 rescue medical team of Tianjin Third Central Hospital, from January 8 to February 2, 2022. The clinical characteristics of the patients were analyzed, and the influence of whether the patients were inoculated with booster vaccination on the condition and outcome was analyzed. Data were collected including epidemiological, clinical features, laboratory and imaging examination, treatment measures and clinical outcomes, and difference between groups was analyzed. A total of 362 patients were included, including 136 cases (37.57%) in the booster group, 190 cases (52.49%) in the routine vaccination group, and 36 cases (9.94%) in the unvaccinated group. There was a trend of concentrated distribution of patients, of which 171 cases (47.24%) patients showed family clustering, involving 69 families. Seventy-four cases (20.44%) of the 362 patients had one or more underlying diseases, mainly hypertension (64 cases, 17.68%), diabetes mellitus (23 cases, 6.35%), and coronary heart disease (18 cases, 4.97%); 215 patients (59.39%) had one or more discomfort symptoms, mainly cough (158 cases, 43.65%), pharyngeal discomfort (154 cases, 42.54%) and fever (136 cases, 37.57%). The diagnostic typing was mild type in 194 cases (53.59%), moderate type in 165 cases (45.58%) and severe type in 3 cases (0.83%). The patients had elevated immunoglobulin G (IgG) antibody titers to the novel coronavirus on admission [23.17 (3.08, 60.77)]. Patients were medically isolated and the main treatment measures included traditional Chinese medicine identification (Chinese medicine or tonics) in 265 cases (73.20%), prone treatment in 188 cases (51.93%), anticoagulation with low-molecular heparin in 106 cases (29.28%), immunomodulatory therapy with thymofacine in 21 cases (5.80%), antimicrobial drugs in 20 cases (5.52%), transnasal high-flow oxygen therapy in 12 cases (3.31%), glucocorticoids in 5 cases (1.38%), non-invasive mechanical ventilation in 1 case (0.28%), and invasive mechanical ventilation in 1 case (0.28%). A total of 362 patients were discharged with no deaths, of which 12 patients (3.31%) were admitted to the intensive care unit (ICU). The median duration of illness was 13 (10, 15) days, the median length of hospitalization was 13 (11, 15) days, and the median time to nucleic acid conversion was 13 (10, 15) days. Compared with the unvaccinated group, the IgG antibody titers of patients in the booster and routine vaccination groups [41.49 (20.32, 81.38), 19.94 (2.33, 49.25) vs. 0.16 (0.07, 1.94)] and the proportion of mild patients [66.91% (91/136), 48.94% (93/190) vs. 27.28% (10/36)] were higher, which were also higher in the booster vaccination group than in the conventional vaccination group (all P < 0.05). Compared to the conventional and booster vaccination groups, the unvaccinated group had a higher proportion of severe patients [5.56% (2/36) vs. 0.53% (1/190), 0 (1/136)], longer time to nucleic acid conversion [days: 15 (11, 16) vs.12 (10, 15), 13 (11, 15)], and longer disease duration [days: 15 (11, 16) vs. 12 (10, 15), 13 (11, 15)], and a higher percentage of ICU admissions [16.67% (6/36) vs. 2.63% (5/190), 0.74% (1/136)], with statistically significant differences among the three groups (all P < 0.05). Omicron variant is extremely infectious with aggregated onset, but its clinical symptoms are mild. The vaccine, especially the booster vaccination, remains effective in preventing severe-stage progression and improving prognosis in patients with Omicron variant infection.

Comparison of COVID-19 Inactivated Virus Vaccine Immunogenicity Between Healthy Individuals and Patients on Hemodialysis: A Single-Center Study From Pakistan.

IntroductionThis study compares the immune response after coronavirus disease 2019 (COVID-19) inactivated virus vaccine between healthy individuals (HI) and patients on hemodialysis (HD).MethodsIn this cross-sectional, comparative study, the presence or absence of immunoglobulin G (IgG) anti-S antibody and IgG anti-S antibody titer was compared between HI, and patients on HD after two doses of COVID-19 vaccine.ResultsA total of 81 participants, 50 (61.7%) HD patients and 31 (38.3%) HI, were studied. The mean age was 52.9±12 in HD patients and 42±12.4 in HI. Vaccination responder rates were 80.6% in HI and 72% in HD patients after the first dose (p=0.38) and 93.5% in HI and 94% in HD at the third week of the second dose of the vaccine (p=0.93). The mean IgG antibody titer was 156.3±113.8 in HI and 143.4 ± 117.8 in HD patients (p=0.538) after the first dose and 186.7 ± 97.9 in HI and 180.6 ± 105.8 in HD patients (p=0.552) at three weeks of the second dose. No statistically significant difference was found in antibody titer with respect to gender, age, vaccine (BBIBP-CorV or Conovac), and hypertension. Diabetic HD patients had a lower antibody titer than non-diabetic HD patients (p=0.03) while participants who had a history of COVID-19 infection had a higher IgG titer (p = 0.001). The levels of IgG titer in the same patient increased, corresponding to the doses of vaccine (p <0.001). No HD patient developed COVID-19 infection till the third week of vaccination.ConclusionThis study demonstrates a similar humoral response after COVID-19 inactivated virus vaccination in HD patients and HI. The response was lower among diabetic patients on HD and better in those with previous COVID-19 infection.

Anti-SARS-CoV-2 IgG and Neutralizing Antibody Levels in Patients with Past COVID-19 Infection: A Longitudinal Study

Background:Monitoring the longevity of immunoglobulin G (IgG) responses following severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections is vital to understanding the role of antibodies in preventing infection.Aims:To determine the quantitative IgG responses specific to the Spike-S1 (S1) receptor-binding domain (S1/RBD) region of the virus in serum samples taken between 4 weeks and 7 months after polymerase chain reaction (PCR) positivity in patients who are diagnosed with coronavirus disease-2019 (COVID-19).Study Design:A longitudinal study.Methods:This study included 113 patients with a clinical and molecular diagnosis of COVID-19. The first and second serum samples were taken 1 and 7 months, respectively, after the PCR positivity. S1/RBD-specific IgG antibody response was assayed using anti-SARS-CoV- 2 QuantiVac ELISA (IgG) kit (Euroimmun, Lübeck, Germany). The neutralizing antibodies were investigated in 57 patients whose IgG test results were above the cut-off value.Results:In 57 patients with SARS-CoV-2 IgG, the anti-SARS-CoV-2 IgG quantitative antibody levels significantly decreased after 7 months (Z = −2.197, p = 0.028). A correlation was detected between the anti-SARS-CoV-2 IgG and nAb percent inhibition (IH%) levels detected in 1 month (rs = 0.496, p < 0.001), but without significant correlation in serum samples taken on 7 months. The nAb IH% levels of the first and second were compared for COVID-19 severity and revealed no statistical difference (p = 0.256). In the second serum sample, the nAb IH%s of patients with moderate COVID-19 showed a statistically significant difference from patients with mild COVID-19 (p = 0.018), but without significant differences between severe and moderate or mild COVID-19.Conclusion:SARS-CoV-2 quantitative IgG antibody titers are significantly reduced at long-term follow-up (> 6 months). Due to the limited information on seroconversion, comprehensive studies should be conducted for long-term follow-up of the immune response against SARS-CoV-2.

Epidemiological characteristic of rubella by age group during 12 years after the national introduction of rubella vaccine in Hangzhou, China

ABSTRACT This study aimed to evaluate the implementation and impact of rubella-containing vaccine (RCV) by describing the rubella epidemiology and seroepidemiology in Hangzhou. We collected rubella cases of Hangzhou in the Information System for Disease Control and Prevention in China between 2009 and 2020, and performed a descriptive analysis. We applied a multi-stage stratified random sampling method to recruit participants for serological tests of rubella. Enzyme Linked Immunosorbent Assay (ELISA) was used to detect Immunoglobulin G (IgG) antibodies against rubella in serum samples. Univariate and multivariate analyses are used to detect the association between the level of rubella IgG and related factors. The incidence of rubella cases per million population decreased from 15.8 in 2009 to .1 in 2020. The proportion of rubella cases in women of childbearing age was higher than in men. A total of 4,362 subjects were tested serologically for rubella. The percentage of people whose rubella IgG antibody titers were above the minimum protective level (20 IU/ml) was 80.60% (95% CI: 79.4%–81.8%) and the geometric mean concentration (GMC) for rubella IgG was 58.34 IU/ml. The data indicated that Hangzhou had made good progress toward the elimination of rubella, whereas women of childbearing age still had a higher proportion of rubella cases, which might lead to increased risk of subsequent CRS. The positive rate and GMC of rubella IgG were significantly influenced by age and immunization history of RCV. Therefore, we should stress the importance of pushing forward the campaign for supplementary vaccination of rubella in adults.