Persistence Of Antibodies Research Articles

Immunogenicity and safety of BNT162b2 vaccination in adolescents with systemic lupus erythematosus.

We evaluated the immunogenicity and safety of BNT162b2 vaccination in adolescents with systemic lupus erythematosus (adoSLE) receiving either high- or low-dose immunosuppressant (High-IS and Low-IS). Patients aged 12-18years diagnosed with SLE were enrolled. High-IS was defined as >7.5mg/day prednisolone or with other immunosuppressant, while Low-IS was defined as only ≤7.5mg/day of prednisolone and no immunosuppressant. Two doses of BNT162b2 vaccination were given 4weeks apart, followed by a booster (third) dose at 4-6months later. Anti-spike receptor binding domain (anti-RBD) IgG against Wuhan, neutralising antibody (NT) against Wuhan and Omicron variants, and cellular immune response by IFN-γ-ELISpot assay were evaluated following vaccination. Adverse events (AEs) and SLE flare were monitored. A total of 73 participants were enrolled, 40 and 33 in the High-IS and Low-IS group, respectively. At 4weeks following the 2nd dose, overall anti-RBD IgG seropositivity was 97.3%, with no difference between the groups (p = .498). AdoSLE on High-IS had lower anti-RBD IgG (p < .001), Wuhan NT (p < .001), and IFN-γ-ELISpot (p = .022) than those on Low-IS. A 3rd dose induced significantly higher antibody responses than after the 2nd dose (p < .001) in both groups and established seroconversion against Omicron variants, with persistent lower antibody levels in High-IS group. SELENA-SLEDAI scores within 12weeks after 2-dose vaccination was higher than before vaccination (3.1 vs 2.5; p < .036); however, the occurrence of disease flare by SELENA-SLEDAI flare index was not different after vaccination compared to before vaccination, consistent across groups. Non-severe AEs occurred similarly in both groups. AdoSLE on High-IS induced lower SARS-CoV-2 vaccine immune responses than Low-IS. Vaccination can increase disease activity and requires close monitoring for disease flare.

CRISPR/Cas9-edited duck enteritis virus expressing Pmp17G of Chlamydia psittaci induced protective immunity in ducklings.

Chlamydia psittaci is threatening to the animal industry and human beings. Live attenuated duck enteritis virus (DEV) is considered a good vaccine vector. In the present study, the Pmp17G antigen of C. psittaci was expressed in DEV to construct a recombinant DEV-Pmp17G vaccine. The growing curve of the rDEV-Pmp17G vaccine was comparable to the parental DEV strain, and Pmp17G protein expression was detected in the cytosol and membrane of the infected host cells. A total of 30 ducklings assigned to 5 groups were used to evaluate the vaccine efficacy. The birds in the vaccine groups received 15 000 plaque forming units of the rDEV-Pmp17G vaccine via hypodermic injection. In contrast, the control groups received intramuscular inoculation with 1×103 embryo lethal dose of DEV vector or 50µg of commercial recombinant major outer membrane protein (MOMP) vaccine. The rDEV-Pmp17G vaccine induced significantly higher levels of IgG antibodies than the commercial MOMP did on day 14, and the IgG antibodies persisted for 28 days. Moreover, the rDEV-Pmp17G vaccine also induced higher levels of lymphocyte proliferations compared to the DEV vector. The vaccinated animals significantly reduced lesions and enhanced bacterial clearance in the lungs and throats compared to the MOMP immunization. Thus, the rDEV-Pmp17G vaccine induced persistent IgG antibodies and lymphocyte proliferation against C. psittaci infection.

Persistence of Anti-SE36 Antibodies Induced by the Malaria Vaccine Candidate BK-SE36/CpG in 5-10-Year-Old Burkinabe Children Naturally Exposed to Malaria.

Information on the dynamics and decline/persistence of antibody titres is important in vaccine development. A recent vaccine trial in malaria-exposed, healthy African adults and children living in a malaria hyperendemic and seasonal area (Ouagadougou, Burkina Faso) was the first study in which BK-SE36/CpG was administered to different age groups. In 5- to 10-year-old children, the risk of malaria infection was markedly lower in the BK-SE36/CpG arm compared to the control arm. We report here data on antibody titres measured in this age-group after the high malaria transmission season of 2021 (three years after the first vaccine dose was administered). At Year 3, 83% of children had detectable anti-SE36 total IgG antibodies. Geometric mean antibody titres and the proportion of children with detectable anti-SE36 antibodies were markedly higher in the BK-SE36/CpG arm than the control (rabies) arm. The information obtained in this study will guide investigators on future vaccine/booster schedules for this promising blood-stage malaria vaccine candidate.

The impact of ABO blood types on humoral immunity responses and antibody persistency after different COVID-19 vaccine regimens.

This study evaluated the possible effects of blood types on coronavirus disease (COVID-19) vaccine immunogenicity and antibody (Ab) persistency. Five different vaccinated groups against COVID-19 were investigated at Pasteur Institute of Iran from April 2021 to December 2022. Anti-Spike IgG and neutralizing Ab rise were tracked on Day 21 as well as the humoral immune persistency assessment 180 after booster shots. Late adverse events up to 6 months after the booster dose were collected. The results showed that blood type A, led to a significantly higher anti-Spike Ab rise in AstraZeneca primed recipients in comparison with Sinopharm primed ones in heterologous regimens (p: 0.019). Furthermore, blood type O was a great co-effector in homologous AstraZeneca recipients regarding neutralizing Ab rise (0.013). In addition, blood type O led to a better anti-Spike Ab persistency in the Sinopharm homologous group whereas type A had the best effect on neutralizing Ab durability in the same vaccine group. What is more, Rh-positive individuals in AstraZeneca + PastoCovac Plus group had a higher rate of anti-Spike Ab rise (p = 0.001). Neutralizing Ab rise was also induced in AstraZeneca homologous and heterologous regimens of Rh-positive individuals significantly higher than Sinopharm primed cases. The present study showed the potential impact of blood types A/O and Rh-positive on a better humoral immune responses and Ab persistency. It is proposed that blood type A and Rh-positive could increase the Ab rise in AstraZeneca vaccinated individuals. Moreover, blood type O might be a better co-effector of anti-Spike Ab persistency in Sinopharm recipients.

High seroprevalence of severe acute respiratory syndrome coronavirus 2 among healthcare workers in Yaoundé, Cameroon after the first wave of Covid-19 pandemic and associated factors.

Healthcare workers (HWs) are at a high risk of exposure to emerging health threats. Following the first wave of the coronavirus disease 2019 pandemic in Cameroon, we explored the presence and persistence of naturally acquired antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the factors associated with seropositivity in HWs. Staff at two referral hospitals in Yaoundé or two Health District Hospitals in Obala and Mbalmayo were included in a 6-month prospective cohort analysis or cross-sectional survey, respectively. Seroprevalence and associated factors were determined, and Kaplan-Meier curves and Cox proportional hazards models were used to assess antibody persistence or positive seroconversion over time. From August 2020 to March 2021, 426 HWs (median age: 31 years, interquartile range: 27-37 years; 66.4% female) were enrolled. The overall seroprevalence of anti-SARS-CoV-2 antibodies was 54.0% (95% confidence interval [CI]: 49.1-58.8) and was significantly different between study sites (p = 0.04). Of the 216 HWs included in the 6-month cohort, 109 (50.5%) HWs were seropositive at inclusion; the probability of persistent antibodies or of becoming seropositive was 93.8% (95% CI: 84.2-100) and 78.9% (95% CI: 61.7-88.4), respectively. Seroconversion was associated with study site and occupation but not with infection prevention and control (IPC) practices. We observed high seroprevalence of SARS-CoV-2 antibody and seroconversion among HWs associated with occupational risk. This suggests low compliance to the COVID-19 control measures. Continued training and implementation of IPC measures and accelerated preparedness are needed to better tackle future threats.

Sustained S-IgG and S-IgA antibodies to Moderna's mRNA-1273 vaccine in a Sub-Saharan African cohort suggests need for booster timing reconsiderations.

This study sought to elucidate the long-term antibody responses to the Moderna mRNA-1273 COVID-19 vaccine within a Ugandan cohort, aiming to contribute to the sparse data on m-RNA vaccine immunogenicity in Sub-Saharan Africa. We tracked the development and persistence of the elicited antibodies in 19 participants aged 18 to 67, who received two doses of the mRNA-1273 vaccine. A validated enzyme-linked immunosorbent assay (ELISA) was used to quantify SARS-CoV-2-specific IgG, IgM, and IgA antibodies against the spike (S) and nucleoproteins (N). The study's temporal scope extended from the baseline to one year, capturing immediate and long-term immune responses. Statistical analyses were performed using the Wilcoxon test to evaluate changes in antibody levels across predetermined intervals with the Hochberg correction for multiple comparisons. Our results showed a significant initial rise in spike-directed IgG (S-IgG) and spike-directed IgA (S-IgA) levels, which remained elevated for the duration of the study. The S-IgG concentrations peaked 14 days afterboosting, while spike-directed IgM (S-IgM) levels were transient, aligning with their early response role. Notably, post-booster antibody concentrations did not significantly change. Prior S-IgG status influenced the post-priming S-IgA dynamics, with baseline S-IgG positive individuals maintaining higher S-IgA responses, a difference that did not reach statistical difference post-boost. Three instances of breakthrough infections: two among participants who exhibited baseline seropositivity for S-IgG, and one in a participant initially seronegative for S-IgG. In conclusion, the mRNA-1273 vaccine elicited robust and persistent S-IgG and S-IgA antibody responses, particularly after the first dose, indicating potential for long-term immunity. Prior viral exposure enhances post-vaccination S-IgA responses compared to naive individuals, which aligned with the prior-naïve, post-boost. The stable antibody levels observed post-booster dose, remaining high over an extended period, with no significant secondary rise, and no difference by baseline exposure, suggest that initial vaccination may sufficiently prime the immune system for prolonged protection in this population, allowing for potential to delay booster schedules as antibody responses remained high at the time of boosting. This finding calls for a reassessment of the booster dose scheduling in this demographic.

Anti-spike antibody durability after SARS-CoV-2 vaccination in adolescent solid organ transplant recipients.

Adolescent solid organ transplant recipients (aSOTRs) who received three doses of the COVID-19 mRNA vaccine experience high seroconversion rates and antibody persistence for up to 3 months. Long-term antibody durability beyond this timeframe following three doses of the SARS-CoV-2 mRNA vaccine remains unknown. We describe antibody responses 6 months following the third vaccine dose (D3) of the BNT162b2 mRNA vaccination among aSOTRs. Participants in a multi-center, observational cohort who received the third dose of the vaccine were analyzed for antibodies to the SARS-CoV-2 spike protein receptor-binding domain (Roche Elecsys anti-SARS-CoV-2-S positive: ≥0.8, maximum: >2500 U/mL). Samples were collected at 1-, 3-, and 6-months post-D3. Participants were surveyed at each timepoint and at 12-months post-D3. All 34 participants had positive anti-RBD antibody titers 6 months post-D3. Variations in titers occurred between 3 and 6 months post-D3, with 8/28 (29%) having decreased antibody levels at 6 months compared to 3 months and 2/28 (7%) reporting increased titers at 6 months. The remaining 18/28 (64%) had unchanged antibody titers compared to 3-month post-D3 levels. A total of 4/34 (12%) reported breakthrough infection within 6 months and 3/32 (9%) reported infection after 6-12 months following the third dose of the SARS-CoV-2 mRNA vaccine. The results suggest that antibody durability persists up to 6 months following three doses of the SARS-CoV-2 mRNA in aSOTRs. Demography and transplant characteristics did not differ for those who experienced antibody weaning. Breakthrough infections did occur, reflecting immune-evasive nature of novel variants such as Omicron.

Persistence of antibodies 5 years after hepatitis B vaccination in preterm birth children: A retrospective cohort study using real-world data.

Previous studies did not provide substantial evidence for long-term immune persistence after the hepatitis B vaccine (HepB) in preterm birth (PTB) children. Consequently, there is ongoing controversy surrounding the booster immunization strategy for these children. Therefore, we conducted a retrospective cohort study to evaluate the disparities in immune persistence between PTB children and full-term children. A total of 1027 participants were enrolled in this study, including 505 PTB children in the exposure group and 522 full-term children in the control group. The negative rate of hepatitis B surface antibody (HBsAb) in the PTB group was significantly lower than that in the control group (47.9% vs. 41.4%, p = .035). The risk of HBsAb-negative in the exposure group was 1.5 times higher than that in the control group (adjusted odds ratio [aOR] = 1.5, 95% confidence interval [CI]: 1.1-2.0). The geometric mean concentration (GMC) of HBsAb was much lower for participants in the exposure group compared to participants in the control group (9.3 vs. 12.4 mIU/mL, p = .029). Subgroup analysis showed that the very preterm infants (gestational age <32 weeks) and the preterm low birth weight infants (birth weight <2000 g) had relatively low GMC levels of 3.2 mIU/mL (95% CI: 0.9-11.1) and 7.9 mIU/mL (95% CI: 4.2-14.8), respectively. Our findings demonstrated that PTB had a significant impact on the long-term persistence of HBsAb after HepB vaccination. The very preterm infants (gestational age <32 weeks) and the preterm low birth weight infants (birth weight <2000 g) may be special populations that should be given priority for HepB booster vaccination.

An α-Gal antigenic surrogate as a biomarker of treatment evaluation in Trypanosoma cruzi-infected children. A retrospective cohort study.

Proper evaluation of therapeutic responses in Chagas disease is hampered by the prolonged persistence of antibodies to Trypanosoma cruzi measured by conventional serological tests and by the lack of sensitivity of parasitological tests. Previous studies indicated that tGPI-mucins, an α-Gal (α-d-Galp(1→3)-β-d-Galp(1→4)-d-GlcNAc)-rich fraction obtained from T. cruzi trypomastigotes surface coat, elicit a strong and protective antibody response in infected individuals, which disappears soon after successful treatment. The cost and technical difficulties associated with tGPI-mucins preparation, however, preclude its routine implementation in clinical settings. We herein developed a neoglycoprotein consisting of a BSA scaffold decorated with several units of a synthetic α-Gal antigenic surrogate (α-d-Galp(1→3)-β-d-Galp(1→4)-β-d-Glcp). Serological responses to this reagent, termed NGP-Tri, were monitored by means of an in-house enzyme-linked immunosorbent assay (α-Gal-ELISA) in a cohort of 82 T. cruzi-infected and Benznidazole- or Nifurtimox-treated children (3 days to 16 years-old). This cohort was split into 3 groups based on the age of patients at the time of treatment initiation: Group 1 comprised 24 babies (3 days to 5 months-old; median = 26 days-old), Group 2 comprised 31 children (7 months to 3 years-old; median = 1.0-year-old) and Group 3 comprised 26 patients (3 to 16 years-old; median = 8.4 years-old). A second, control cohort (Group 4) included 39 non-infected infants (3 days to 5 months-old; median = 31 days-old) born to T. cruzi-infected mothers. Despite its suboptimal seroprevalence (58.4%), α-Gal-ELISA yielded shorter median time values of negativization (23 months [IC 95% 7 to 36 months] vs 60 months [IC 95% 15 to 83 months]; p = 0.0016) and higher rate of patient negative seroconversion (89.2% vs 43.2%, p < 0.005) as compared to conventional serological methods. The same effect was verified for every Group, when analyzed separately. Most remarkably, 14 out of 24 (58.3%) patients from Group 3 achieved negative seroconversion for α-Gal-ELISA while none of them were able to negativize for conventional serology. Detailed analysis of patients showing unconventional serological responses suggested that, in addition to providing a novel tool to shorten follow-up periods after chemotherapy, the α-Gal-ELISA may assist in other diagnostic needs in pediatric Chagas disease. The tools evaluated here provide the cornerstone for the development of an efficacious, reliable, and straightforward post-therapeutic marker for pediatric Chagas disease.

Risk Factors for Antiphospholipid Antibodies and Antiphospholipid Syndrome.

Persistence of serum antiphospholipid antibodies (aPL) is associated with a high thrombotic risk, both arterial and venous, and with pregnancy complications. Due to the potential morbidity and mortality associated with the presence of aPL, identifying and recognizing risk factors for the development of aPL and thrombosis in aPL carriers may help to prevent and reduce the burden of disease. Multiple elements are involved in the pathomechanism of aPL development and aPL-related thrombosis such as genetics, malignancy, and infections. This review will address the role of both well-known risk factors and their evolution, and of emerging risk factors, including COVID-19, in the development of aPL and thrombosis in aPL carriers.

Erythrokinetic mechanism(s) causing the "late anemia" of hemolytic disease of the fetus and newborn.

A transfusion-requiring "late anemia" can complicate the management of neonates convalescing from hemolytic disease of the fetus and newborn (HDFN). This anemia can occur in any neonate after HDFN but is particularly prominent in those who received intrauterine transfusions and/or double-volume exchange transfusions. Various reports describe this condition as occurring based on ongoing hemolysis, either due to passive transfer of alloantibody through breast milk or persistence of antibody not removed by exchange transfusion. However, other reports describe this condition as the result of inadequate erythrocyte production. Both hypotheses might have merit, because perhaps; (1) some cases are primarily due to continued hemolysis, (2) others are primarily hypoproductive, and (3) yet others result from a mixture of these two mechanisms. We propose prospective collaborative studies that will resolve this issue by serially quantifying end-tidal carbon monoxide. Doing this will better inform the assessment and treatment of neonates recovering from HDFN.

Antibody persistence of standard versus double three-dose hepatitis B vaccine in liver transplant children: a randomized controlled trial

Rapid hepatitis B (HB) surface antibody (anti-HBs) loss is prevalent after liver transplantation (LT). Herein, we evaluated anti-HBs persistence after HB vaccination using two regimens in LT children. We recruited 66 previously immunized LT children with anti-HBs level of < 100 mIU/mL. Participants were randomly reimmunized with standard-three-dose (SD) and double-three-dose (DD) intramuscular HB vaccination at 0, 1, and 6 months. Anti-HBs were assessed at every outpatient visit. Antibody loss defined as anti-HBs levels < 100 mIU/mL after three-dose vaccination. After three-dose vaccination, 81.8% and 78.7% of participants in the SD and DD groups, had anti-HBs levels > 100 mIU/mL, with a geometric mean titer (GMT) of 601.68 and 668.01 mIU/mL (P = 0.983). After a mean follow-up of 2.31 years, the anti-HBs GMT was 209.81 and 212.61 mIU/mL in the SD and DD groups (P = 0.969). The number of immunosuppressants used and an anti-HBs level < 1 mIU/mL at baseline were independently associated with anti-HB loss. The DD regimen strongly increased the risk of anti-HBs loss (adjusted hazard ratio, 2.97 [1.21–7.31]; P = 0.018). The SD HB reimmunization regimen effectively maintained protective anti-HBs levels in children undergoing LT, making it the preferred regimen for such children with anti-HB loss.Trial registration: TCTR20180723002.

A stronger antibody response in increased disease severity of SARS-CoV-2

BackgroundAn assessment of the factors that interfere with serum levels and the persistence of anti-SARs-CoV-2 IgG antibodies is essential in order to estimate the risk of reinfection and to plan vaccination. We analyzed the impact of the severity of coronavirus disease 2019 (COVID-19) and the clinical and biological factors regarding the persistence of SARs-CoV-2 anti-spike protein (IgG-S) antibodies at 12 months.MethodsThis was an observational, longitudinal study with individuals who had recovered from COVID-19 between August 2020 and June 2021. Peripheral blood samples were collected from volunteers who were hospitalized (SERIOUS COVID-19) and those who required no hospitalization (COVID-19 LIGHT). Samples were grouped according to days after symptom onset: up to 90, between 91 and 180, ≥ 180 days after symptom onset. A semiquantitative test for IgG anti-spike protein S1(IgG-S1) was used.ResultsWe analyzed 238 individuals who had recovered from COVID-19, of whom 87 had been hospitalized and 151 had not. They provided 148 and 220 samples, respectively. Among those hospitalized, males (65.5%), volunteers aged over 60 years (41.1%), comorbidities such as arterial hypertension (67.8%) and diabetes mellitus (37.9%) were most frequent. We observed higher median serum IgG-S1 titers among those who had recovered from COVID-19 and had been hospitalized, at all collection time intervals (p < 0.001). We observed a weak correlation of increasing age with humoral IgG-S1 response (Spearman correlation = 0.298). There was a greater probability of IgG-S1 antibody persistence over time among samples from hospitalized individuals compared to samples from non-hospitalized participants (p = 0.001).ConclusionThis study has revealed higher titers and a higher probability of the persistence of IgG-S1 in severe cases after SARs-CoV-2 primary infection in unvaccinated recovered patients. Thus, in this study, the severe clinical presentation of COVID-19 was the main factor influencing serum levels and the persistence of IgG-S1 antibodies in COVID-19.

The Elecsys® Anti-SARS-CoV-2 and Elecsys® Anti-SARS-CoV-2 S antibody assays: Differentiating between vaccination and infection, and assessing long-term performance.

Serological surveillance is useful for assessing SARS-CoV-2 immunity in populations. To effectively study the presence and persistence of antibodies, it is necessary to distinguish between persons with past infection, and persons who only received vaccination. Knowledge of the duration of antibody persistence is essential for correct interpretation of surveillance results. Starting in April 2020, waning of SARS-CoV-2 antibodies was studied in a longitudinal cohort study of 495 SARS-CoV-2 antibody-positive Dutch blood donors, not pre-selected by PCR testing or disease severity. Additionally, in May 2021, a sample of donors representative for the Dutch population was tested for antibodies against the SARS-CoV-2 spike (S) protein, using the Wantai Ab ELISA and the Elecsys® Anti-SARS-CoV-2 S assay; and for antibodies against the nucleocapsid protein, which indicate past infection, using the Elecsys® Anti-SARS-CoV-2 assay. The anti-S response in donors that were infected in April or May 2020 remained positive in 100% of donors in the Elecsys® Anti-SARS-CoV-2 S assay one year after infection, after which follow up of waning was no longer possible because of large scale vaccination. The anti-nucleocapsid response results were still positive in approximately 80% of donors two years after infection. In May 2021, 51% of the donors showed anti-S reactivity and 16.8% tested positive for anti-nucleocapsid antibodies. Infection with SARS-CoV-2 resulted in spike and nucleocapsid antibody levels still detectable in the majority of donors 1-2 years after infection. In May 2021, 51% of donors were vaccinated and 16.8% had had an infection. Thus, both Elecsys® SARS-CoV-2 antibody assays can be used to reliably assess the vaccination and infection status of individuals.

Infection - The Comrade of Acute Pancreatitis in Systemic Lupus Erythematosus: A Case Series from Single Tertiary Centre in India

Introduction: Acute Pancreatitis in systemic lupus Erythematous is rare but has high mortality. Incidence varies from 1-5% and reported mortality is 3-37.04% with mortality being higher in juvenile SLE. Objective: Study of Clinical and serological profile of SLE patients presenting with acute pancreatitis. Method: Retrospective data of SLE patients visiting our institution was collected. Diagnosis was considered if patients had clinical + biochemical and radiological evidence of pancreatitis. Patients with diagnosis of gallstone, history of alcohol intake, serum Triglycerides&gt;500 mg/dl, serum calcium&gt;10.5 mg/dl and taking Azathioprine at the time of diagnosis were excluded. Results: 9 patients fulfilled inclusion and exclusion criteria. 7 had severe and 2 had moderately severe acute pancreatitis. Female: Male ratio was 8:1, Median age was 25(15-50) years, Median disease duration 12 months (3-48), 4(44.45%) presented within 1 year of disease onset. Mean SELENA-SLEDAI at the time of presentation was 26(19-41). 4(44.45%) were on corticosteroids at the time of presentation. Other active domains at the time of diagnosis were Nephritis in 7(77.78%), NPLE in 3(33.34%), Myositis in 4(44.45%), Autoimmune haemolytic anaemia in 2 (22.22%), Macrophage activation syndrome in 4 (44.45%) enteritis in 1 (11.11%) Myocarditis in 2 (22.22%) and Mucocutaneous in 9 (100%) patients. All patients had elevated Serum Amylase and Lipase level with Median serum Amylase being 545 Units/Litre (normal[Formula: see text]176) and median serum Lipase being 511 ([Formula: see text]160) Units/litre. 6(66.67%) had hypocalcemia and 5 (55.56%) had hypertriglyceridemia. Raised dsDNA was seen in 9(100%, median 277 IU/ml) and hypocomplementemia was seen in 7(77.78%, Median C3 value 49 mg/dL)). None of the patients had associated antiphospholipid syndrome but persistent antiphospholipid antibodies were present in 5(55.56%)-4 had lupus anticoagulant and 1 had Anticardiolipin antibody. 6(66.67%) patients had microbiologically confirmed infection the time of diagnosis of acute pancreatitis (4 bacterial and 1 fungal) among which 3 had lower respiratory tract infection, 1 had urinary tract infection, 1 had pseudomembranous colitis and 1 had peri-pancreatic abscess. 7 patients received only corticosteroids, and 2 patients received IVIG with corticosteroids. 3 out of 9 patients (33.34%) expired due to multi-organ failure. Out of 6 surviving patients all received IV cyclophosphamide (NIH protocol) and are doing fine. Conclusion: Acute pancreatitis in SLE has high mortality probably due to associated high clinical and serological disease activity and high incidence of concomitant infection. Extensive investigation for underlying infection (bacterial, viral and fungal) should be done in SLE patients presenting with acute pancreatitis for comprehensive management.

Detectable immunological response in Brucella abortus s 19 vaccinated herds of cattle in vilachchiya veterinary range, north central province, Sri Lanka

Brucellosis a zoonotic disease caused by Gram-negative, intracellular, coccobacillus. Brucellosis, an economically important disease in livestock with zoonotic implications has been reported worldwide. It is transmitted via contaminated animals and their products. Clinical signs of animal brucellosis are abortions, reduced fertility, retention of fetal membranes, endometritis, and substantial decline in milk production over an animal’s lifespan. Orchitis, epididymitis and chronic hygroma had been reported in bulls. The current study focused on to studying the detectable immunological responses to Brucella S 19 live attenuated vaccine using serological tests in cattle of dry zone farms. A questionnaire-based survey was carried out in selected farms with and without a previous history of abortion respectively. Animals that were in 1st to 5th lactation in the 18 farms were selected for screening by Rose Bengal Plate Test (RBPT) and positives were confirmed by Complement Fixation Test (CFT). Three farms each with and without history of abortion were selected for Brucella S19 vaccination from the RBPT and CFT negative farms. Sixty non pregnant heifers over 6 months were selected, and 1ml each of S19 vaccine was given subcutaneously to 30 animals while 30 animals were kept as controls. The serum samples were collected and screened for Brucellosis by RBPT and CFT at 2, 4, 6, 8 and 10 weeks of post vaccination. The second week after the vaccination, 71.42% of the animals showed over 1:4 CFT levels while 28.57% of them did not show any antibody titres for Brucellosis in the Brucella endemic farms. In Brucella non-endemic farms, 68.75% of animals showed over 1:4 CFT titre at 2 weeks after the vaccination. However, 31.25% of animals did not show any CFT titre. No persistent and detectable antibody responses were found 10 weeks post vaccination in heifers of endemic and non-endemic herds. The titers of CFT indicate IgG or IgM humeral response, cell mediated immune response of live attenuated vaccine has not been monitored in the study. Thus, seropositivity after the 10 weeks post vaccination may indicate an infection of Brucellosis since no antibodies from vaccination were found. Further investigation with highly sensitive tests such as ELISA is recommended to have a better insight into this aspect in the future.

Immunogenicity and durability against Omicron BA.1, BA.2 and BA.4/5 variants at 3–4 months after a heterologous COVID-19 booster vaccine in healthy adults with a two-doses CoronaVac vaccination

BackgroundSeveral countries have authorized a booster vaccine campaign to combat the spread of COVID-19. Data on persistence of booster vaccine‐induced immunity against new Omicron subvariants are still limited. Therefore, our study aimed to determine the serological immune response of COVID-19 booster after CoronaVac-priming. MethodsA total of 187 CoronaVac-primed participants were enrolled and received an inactivated (BBIBP), viral vector (AZD1222) or mRNA vaccine (full-/half-dose BNT162B2, full-/half-dose mRNA-1273) as a booster dose. The persistence of humoral immunity both binding and neutralizing antibodies against wild-type and Omicron was determined on day 90–120 after booster. ResultsA waning of total RBD immunoglobulin (Ig) levels, anti-RBD IgG, and neutralizing antibodies against Omicron BA.1, BA.2, and BA.4/5 variants was observed 90–120 days after booster vaccination. Participants who received mRNA-1273 had the highest persistence of the immunogenicity response, followed by BNT162b2, AZD1222, and BBIBP-CorV. The responses between full and half doses of mRNA-1273 were comparable. The percentage reduction of binding antibody ranged from 50 % to 75 % among all booster vaccine. ConclusionsThe antibody response substantially waned after 90–120 days post-booster dose. The heterologous mRNA and the viral vector booster demonstrated higher detectable rate of humoral immune responses against the Omicron variant compared to the inactivated BBIBP booster. Nevertheless, an additional fourth dose is recommended to maintain immune response against infection.

Serological surveillance of GI norovirus reveals persistence of blockade antibody in a Jidong community-based prospective cohort, 2014-2018.

Herd immunity against norovirus (NoV) is poorly understood in terms of its serological properties and vaccine designs. The precise neutralizing serological features of genotype I (GI) NoV have not been studied. To expand insights on vaccine design and herd immunity of NoVs, seroprevalence and seroincidence of NoV genotypes GI.2, GI.3, and GI.9 were determined using blockade antibodies based on a 5-year longitudinal serosurveillance among 449 residents in Jidong community. Correlation between human histo-blood group antigens (HBGAs) and GI NoV, and dynamic and persistency of antibodies were also analyzed. Seroprevalence of GI.2, GI.3, and GI.9 NoV were 15.1%-18.0%, 35.0%-38.8%, and 17.6%-22.0%; seroincidences were 10.0, 21.0, and 11.0 per 100.0 person-year from 2014 to 2018, respectively. Blockade antibodies positive to GI.2 and GI.3 NoV were significantly associated with HBGA phenotypes, including blood types A, B (excluding GI.3), and O+; Lewis phenotypes Leb+/Ley+ and Lea+b+/Lex+y+; and secretors. The overall decay rate of anti-GI.2 antibody was -5.9%/year (95% CI: -7.1% to -4.8%/year), which was significantly faster than that of GI.3 [-3.6%/year (95% CI: -4.6% to -2.6%/year)] and GI.9 strains [-4.0%/year (95% CI: -4.7% to -3.3%/year)]. The duration of anti-GI.2, GI.3, and GI.9 NoV antibodies estimated by generalized linear model (GLM) was approximately 2.3, 4.2, and 4.8 years, respectively. In conclusion, enhanced community surveillance of GI NoV is needed, and even one-shot vaccine may provide coast-efficient health benefits against GI NoV infection.

A CTB-SARS-CoV-2-ACE-2 RBD Mucosal Vaccine Protects Against Coronavirus Infection.

Mucosal vaccines protect against respiratory virus infection by stimulating the production of IgA antibodies that protect against virus invasion of the mucosal epithelium. In this study, a novel protein subunit mucosal vaccine was constructed for protection against infection by the beta coronavirus SARS-CoV-2. The vaccine was assembled by linking a gene encoding the SARS-CoV-2 virus S1 angiotensin converting enzyme receptor binding domain (ACE-2-RBD) downstream from a DNA fragment encoding the cholera toxin B subunit (CTB), a mucosal adjuvant known to stimulate vaccine immunogenicity. A 42 kDa vaccine fusion protein was identified in homogenates of transformed E. coli BL-21 cells by acrylamide gel electrophoresis and by immunoblotting against anti-CTB and anti-ACE-2-RBD primary antibodies. The chimeric CTB-SARS-CoV-2-ACE-2-RBD vaccine fusion protein was partially purified from clarified bacterial homogenates by nickel affinity column chromatography. Further vaccine purification was accomplished by polyacrylamide gel electrophoresis and electro-elution of the 42 kDa chimeric vaccine protein. Vaccine protection against SARS-CoV-2 infection was assessed by oral, nasal, and parenteral immunization of BALB/c mice with the CTB-SARS-CoV-2-ACE-2-RBD protein. Vaccine-induced SARS-CoV-2 specific antibodies were quantified in immunized mouse serum by ELISA analysis. Serum from immunized mice contained IgG and IgA antibodies that neutralized SARS-CoV-2 infection in Vero E6 cell cultures. In contrast to unimmunized mice, cytological examination of cell necrosis in lung tissues excised from immunized mice revealed no detectable cellular abnormalities. Mouse behavior following vaccine immunization remained normal throughout the duration of the experiments. Together, our data show that a CTB-adjuvant-stimulated CTB-SARS-CoV-2-ACE-2-RBD chimeric mucosal vaccine protein synthesized in bacteria can produce durable and persistent IgA antibodies in mice that neutralize the SARS-CoV-2 subvariant Omicron BA.1.1.

Ginseng Polysaccharide Enhances the Humoral and Cellular Immune Responses to SARS-CoV-2 RBD Protein Subunit Vaccines.

The COVID-19 pandemic remarkably accelerated vaccine research progress. The role of adjuvants in enhancing vaccine immune intensity and influencing immune types has been considered. Ginseng polysaccharide (GPS) has been demonstrated to have strong immunoregulatory properties. It is important to explore the feasibility of adding GPS to vaccine adjuvant components to improve the immune response effect of RBD vaccines. Here, we prepared a SARS-CoV-2 RBD antigen using the Escherichia coli expression system and determined that subcutaneous administration of GPS at a dose of 40 mg/kg could effectively activate dendritic cells (DCs) and macrophages (MΦ) in mice. Compared with the RBD group, the RBD+GPS triggered stronger and persistent antibody responses. It is also notable that higher levels of RBD-specific IgG and IgA were distributed in the lungs of RBD+GPS-immunized BALB/c mice. In addition, the RBD+GPS also resulted in lower percentages of IFN-γ+ CD4+ T cells and higher percentages of IFN-γ+ CD8+ T cells and CD8+ Tcm cells. These results suggest that GPS could be a promising vaccine immuno-enhancer for SARS-CoV-2 RBD subunit vaccines to establish stronger systemic and pulmonary mucosal protective immunity.