Heterologous booster COVID-19 vaccination elicited potent immune responses in HCWs

The objective of our study was to evaluate the antibody responses of health care workers (HCWs) who were vaccinated with booster dose BNT162b2 6 months after 2 doses of the CoronoVac vaccine. The study included 318 HCWs vaccinated with inactive CoronaVac SARS-CoV-2 vaccine in 2 doses. Anti-spike/RBD IgG levels were measured immediately before and 1 month after the booster dose. In the sixth month after CoronaVac vaccination, the median of antibody levels of 1212.02 AU/ML, while it was 9283 AU/mL after BNT162b2 vaccination. IgG antibody titers of over 1050 AU/mL (which is equivalent to 1:80 dilution in the plaque reduction neutralization test) were detected in HCWs 15.09% and 97.8%, respectively. Our results showed that antibody titers increased 8-fold after the booster dose. We believe that the administration of the mRNA vaccine as a booster dose can provide more effective protection against COVID-19 infection, especially in individuals with risk factors.IU-Cerrahpaşa Scientific Research Projects Uni

Waning immunity to inactive SARS-CoV-2 vaccine in healthcare workers: Booster required

Aims Despite high vaccination rates, increasing case numbers continue to be reported with the identification of new variants of concern, and the issue of durability of the vaccine-induced immune response remains hot topic. Real-life data regarding time-dependent immunogenicity of inactivated COVID-19 vaccines are scarce. We aimed to investigate the changes in the antibody at the different times after the second dose of the CoronaVac vaccine. Methods The study included 175 HCWs vaccinated with inactive CoronaVac (Sinovac Life Sciences, China) SARS-CoV-2 vaccine in two doses. Anti-spike/RBD IgG levels were measured first, third, and sixth months after the second dose. Chemiluminescent microparticle immunoassay (IgG II Quant test, Abbott, USA), which is 100% compatible with plaque reduction neutralization test, was used. Results Mean age of the participants was 38 +/- 11.23 years (range between 22 and 66) of whom 119 (63.9%) were female, and 56 (32%) were male. Dramatic reductions were demonstrated in median antibody levels particularly in the infection-naive group, comprising 138 HCWs compared to those with prior history of COVID-19 infection (n = 37) (p < 0.001). There was no difference between the two groups in terms of age, gender, blood groups, BMI, and comorbid diseases. Conclusions While antibody positivity remained above 90% in the 6th month after two doses of inactivated vaccine in HCWs, the median titers of neutralizing antibodies decreased rapidly. The decrease was more rapid and significant in those with no history of prior COVID-19 infection. In this critical phase of the pandemic, where we are facing the dominance of the Omicron variant after Delta, booster doses have become vital.IU-Cerrahpasa Scientific Research Projects Uni

Investigation of Brucella Seropositivity in Patients with Suspected Brucellosis: A 4-Year Retrospective Evaluation

Amaç: Brucella cinsi bakterilerle oluşan bruselloz, sistemik bir enfeksiyon hastalığı olup dünyanın birçok ülkesinde yaygın olarak saptanmakta ve ülkemizde de oldukça sık görülmektedir. Çalışmamızın amacı, İstanbul ve çevre illerdeki yerleşim bölgelerinden dört yıllık dönemde bruselloz kuşkusu ile merkezimize başvuran 6.045 olgudan alınan serum örneklerinde bruselloz serolojik göstergelerini retrospektif olarak değerlendirmek ve sonuçları yine merkezimizde 2005-2011 yılları arasında gerçekleştirilmiş çalışmanın verileriyle karşılaştırarak değişkenlikleri irdelemektedir. Yöntem: Çalışmamıza Mart 2013- Mart 2017 tarihleri arasında İstanbul Üniversitesi-Cerrahpaşa, Cerrahpaşa Tıp Fakültesi Hastanesi Tıbbi Mikrobiyoloji Laboratuvarı Seroloji/ELISA birimine gönderilen bruselloz şüpheli olgulara ait serum örnekleri dahil edilmiştir. Örneklerden Brucella Serum Aglütinasyon (SAT), Coombs’lu Wright (CT) ve Rose-Bengal (RB) testleri yapılmıştır. Bulgular: Dört yıllık değerlendirme sonucunda, bruselloz şüpheli 6045 olgunun 107 (%1.8)’si seropozitif, 5938 (%98.2)’i seronegatif bulunmuştur. Brusella seropozitif 107 olgunun 73 (%68.2)’ü RB ve SAT ile eş zamanlı pozitif bulunmuş, 34 (%31.7) olgu ise RB ve SAT test sonuçları arasında uyumsuzluk görülmesi nedeniyle, CT sonucuna göre brusella seropozitif olarak belirlenmiştir. Brusella seropozitiflik oranı kadınlarda (%58) erkeklere (%42) göre daha yüksek olsa da istatistiksel olarak anlamlı bir fark bulunmamıştır. Olguların %28’inde aile içi aynı kaynaktan bulaş, %48’inde kırsal kesimde yaşama öyküsü saptanmıştır. Sonuç: Verilerimizin retrospektif değerlendirmesi sonucunda, bu çalışmada İstanbul ve çevre illerinde saptadığımız bruselloz seropozitiflik oranı (%1.8), aynı merkezde bir önceki dönem elde edilen orana göre (%3) düşük bulunmuştur. Bruselloz seropozitifliğinin oransal düşüklüğünde, son yıllarda görsel ve yazılı iletişim araçlarındaki artışla hayvansal kaynaklı beslenme konusunda daha bilinçli ve hijiyen kurallarına uyan insan kitlelerindeki artışın rolü olabileceğini düşünmekteyiz.Objective: Brucellosis is a systemic infectious disease that is commonly detected in many countries of the world and is very common in our country. The aim of this study was to evaluate the serological markers of brucellosis in 6045 patients from Istanbul and surrounding provinces, who were admitted to our center in a 4-year period and to compare the results with the study conducted between 2005-2011. Method: Serum samples of suspected brucellosis patients who were admitted to Istanbul University-Cerrahpasa, Cerrahpasa Medical Faculty Hospital, Serology / ELISA unit, between March 2013-2017 were included in the study. Brucella Serum Agglutination, Coombs Wright and Rose-Bengal tests were performed. Results: As a result of a 4 years evaluation, 107 (1.8%) of the 6045 suspected brucellosis cases were found seropositive and 5938 (98.2%) of them were seronegative. Of the seropositive 107 cases, 73 (68.2 %) were found to be concurrently positive with RB and SAT; 34 (31.7%) of the cases were seropositive according to CT. Although brucella seropositivity rate was higher in females (58%) than males (42%), no statistically significant difference was found. Of the cases 28% had transmission from the same source within the family and 48% had a history of living in rural areas. Conclusion: Consequently, the seropositivity rate of brucellosis (1.8%) that we found was found to be lower than the rate obtained in the same center (3%) previously. We believe that, by the increase in visual and written communication tools people comply and are more conscious about the hygienic rules on consuming animal based nutrition

Bioactive Components and Antioxidant and Antimicrobial Activities of Rhus coriaria, a Sumac Species found in Turkey

Objective:In our study, it was aimed to analyze the antioxidant and antimicrobial activities of the extracts of the fruits of Rhus coriaria L. (sumac) species collected from Gaziantep.Methods:Ethanol extracts of 80% (R2) and 100% (R3) were prepared from Rhus coriaria fruits. Chemical analysis of the extracts were performed by liquid chromatography-high resolution mass spectrometry method, their antioxidant activities were investigated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, and their antimicrobial activity was investigated using broth microdilution method.Results:In the chemical analysis of R2 and R3 extracts, fumaric acid, an organic acid with the highest concentration, was found at concentrations of 31076.55 and 23348.37 mg/kg, respectively. While the phenolic components with the highest concentration in R2 were observed as hyperoside (622.24 mg/kg), ellagic acid (343.63 mg/kg) and p-coumaric acid (182.91 mg/kg), the phenolic components with the highest concentration in R3 were observed as ellagic acid (607.30 mg/kg), hyperoside (440.41 mg/kg) and p-coumaric acid (178.61 mg/kg). In antioxidant activities of R2 and R3 extracts, DPPH free radical scavenging activities were found to be 70.78%±0.002% and 11.19±0.001%, respectively. Antimicrobial activities of R2 and R3 extracts were found to be 125 and <3.9 µg/ mL in S. aureus strain ATCC 25923, 15.625 and 31.25µg/mL in A. baumannii strain ATCC 19606, 62.5 µg/mL in H. pylori strain ATCC 43504, 62.5 µg/mL in C. glabrata strain ATCC 2001, <3.9 µg/mL in C. albicans strain ATCC 66027, respectively.Conclusion:The higher antioxidant activity in the R2 extract obtained from R. coriaria fruits grown in our country may be due to the higher phenolic component content compared to the R3 extract. It is thought that the more effective antimicrobial activity detected in the R3 extract may be due to the higher amount of ellagic acid compared to the R2 extract

Retrospective analysis of demographic and clinical data in SARS-CoV-2 IgG reactive individuals applied to Cerrahpasa Medical Faculty Hospital: 1 year evaluation

Giriş: SARS-CoV-2 IgG testleri bireyin önceden COVID-19 hastalığını geçirip geçirmediğini, aşı uygulaması sonucu oluşan antikor düzeyini ve toplumdaki COVID-19 seroprevalansını saptamak amacıyla kullanılmaktadır. Çalışmamızda Seroloji/ELISA laboratuvarına infeksiyon şüphesi, infeksiyon geçmişi veya aşı sonrası SARS-CoV-2 IgG düzeyinin saptanması amacıyla başvuran olguların, SARS-CoV-2 IgG düzeylerinin, demografik ve klinik verilerle birlikte retrospektif olarak değerlendirilmesi amaçlanmıştır. Materyal ve Metod: Çalışmaya 4 Ocak 2021-31 Aralık 2021 tarihleri arasında birimimize SARS-CoV-2 IgG test istemiyle başvuran ve antikor testi reaktif saptanan olgular alınmıştır. Olguların demografik ve klinik verileri, geriye dönük sorgulanarak elde edilmiştir. Antikor tespiti için ELISA ve CMIA prensipli test kitleri kullanılmıştır. Bulgular: Çalışmaya SARS-CoV-2 IgG testi reaktif saptanan 549 kişi alınmıştır. Bunların 308’i (%56.10) kadın, 241’i (%43.90) erkek olup yaş ortalamaları 42.31 olarak saptanmıştır. 549 olgunun 159’u (%28.96) ELISA, 390’ı (%71.04) ise CMIA test kitiyle analiz edil- miştir. ELISA yöntemi ile antikor düzeyi belirlenen dönemde infeksiyonu geçiren kişilerde antikor değerleri, aşı sonrası belirlenen antikor değerlerine göre yüksek saptanırken (p 0.05). Sonuç: COVID-19 infeksiyon sonrasında hem humoral hem hücresel immün yanıt geliştiğinden ötürü çalışmamızda ELISA yöntemiy- le çalışılan dönemde infeksiyonu geçiren kişilerin antikor titreleri aşı sonrasına göre yüksek saptanmıştır. Bu sonucun bu dönemde CoronaVac inaktif aşısının uygulanması ve bu aşının daha fazla humoral immün yanıt oluşumuna neden olmasıyla ilişkili olabileceği, ayrıca 61 yaş ve üstü bireylerin antikor düzeylerinin diğer yaş gruplarına göre yüksek saptanmasının aşılanma sürecinde bu yaş aralığı- nın öncelikli olmasından kaynaklandığını düşünmekteyiz. Farklı dönemlerde uygulanan aşı türlerine karşı oluşan antikor titreleri arasında anlamlı farklılık saptanmasa da hatırlatma doz uygulaması sonrasında antikor titrelerinin daha yüksek olduğu belirlenmiştir. Genel popülasyonun hem seroprevalans hem de bağışık yanıtının belirlenmesi için standardizasyona uygun, kantitatif sonuç veren kitlerle geniş ölçekli çalışmaların yapılması gerektiği kanaatindeyiz.Introduction: SARS-CoV-2 IgG tests are used to determine whether an individual has had COVID-19 disease before, the antibody level resulting from vaccination, and the seroprevalence of COVID-19 in the community. Aim of this study was to evaluate the SARS-CoV-2 IgG levels, together with demographic and clinical data retrospectively from the cases who applied to the Serology/ELISA laboratory for suspected infection, history of the disease, or after vaccination. Materials and Methods: Cases that applied to our unit with a SARS-CoV-2 IgG test request between January 4, 2021 and December 31, 2021 and whose antibody test was found to be reactive were included in the study. Demographic and clinical data of the cases were obtained by retrospective examination. ELISA and CMIA based test kits were used for antibody detection. Results: The test was included 549 subjects with reactive SARS-CoV-2 IgG in the study. 308 (56.10%) were female, and 241 (43.90%) were male, with a mean age of 42.31 years. 159 (28.96%) of 549 cases were analyzed with ELISA and 390 (71.04%) with CMIA based test kit. In the period determined by the ELISA method, the antibody titer of the people who had the infection were higher than the antibody titer determined after the vaccination (p 0.05). Conclusion: With the development of humoral and cellular immune response after COVID-19 infection, the antibody titers of people who had the infection during the study period with the ELISA method were found to be higher than after vaccination. Although there was no significant difference between the antibody titers against the vaccine types administered in different periods, it was determined that the antibody titers were higher after the reminder dose administration. We think that the application of the CoronaVac inactivated vaccine in this period and the vaccine causing a more humoral immune response may be related to the fact that the antibody levels of individuals aged 61 and over are higher than other age groups due to the priority of this age range in the vaccination process. We believe that large-scale studies should be conducted with kits suitable for standardization and give quantitative results to determine both seroprevalence and the immune response of the general population

Evaluation of the Diagnostic Performance of SARS-CoV-2 Rapid Antigen Tests in COVID-19 Patients

The gold standard in the definitive diagnosis of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is nucleic acid amplification tests (NAAT) due to their high sensitivity and specificity in de-tecting viral ribonucleic acid. However, while leaving two years behind in the pandemic, resources have come to the point of exhaustion in terms of both the economy and the manpower working in the field of health services. Therefore, the need for rapid, simple and accurate tests to diagnose SARS-CoV-2 infection continues. In this study, it was aimed to compare the performance characteristics of SARS-CoV-2 rapid antigen tests (RAgT) in the diagnosis of coronavirus disease 2019 (COVID-19) cases with the real-time reverse transcription-polymerase chain reaction (rRT-PCR) method. In Istanbul University-Cerrahpaa Fa-culty of Medicine COVID-19 Molecular Diagnosis Laboratory, SARS-CoV-2 RNA positive respiratory tract samples with viral loads of < 25 Ct (cycle of treshold), 25-29 Ct, 30-35 Ct and 35< Ct, a total of 205 patient samples were selected in four groups. SARS-CoV-2 positive samples were studied by lateral flow method (LFA) using twelve commercial RAgTs of different companies and their performances were evalu-ated. In addition, 90 samples were selected from various respiratory tract samples archived, which were sent to our laboratory for the identification of the non-COVID-19 pathogen(s) causing the respiratory tract infection between 2020-2022 and their specificities for RAgTs were evaluated to avoid cross reacti-vity. The sensitivities of the SARS-CoV-2 RAgTs included in the study, ranged from 40.4-97.5%, while the sensitivity of most of the kits (8/12), at 25 Ct values, was _ 90%, which is the minimum limit in the European Centre for Disease Prevention and Control (ECDC)'s guideline for the use of SARS-CoV-2 RAgTs. The specificities of RAgTs were found to be between 90-100%. When the concordance of SARS-CoV-2 RAgTs with rRT-PCR positivity was evaluated with the kappa coefficient, the concordance of only one RAgT was found to be statistically significant (Kappa= 0.88). SARS-CoV-2 RAgTs have a potential use as a diagnostic tool in symptomatic people, as a routine screening tool in community living environments, and in situations such as ending the isolation of the patients. Each country should carry out validation studies before the use of these tests, taking into account of their socio-economic situation, healthcare infrastructure and current epidemiological data of COVID-19

Serological and Molecular Tests Performed Pre-Transplantation on Post-Mortem Cornea Donors: Retrospective Evaluation of 5-Years

Objective: Control of corneal damage with endothelial cell count and serological screening before keratoplasty are critical issues for recipient health. We aimed to detect the pre-transplantation hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and Treponema pallidum serological test results of post-mortem corneal donors and to determine their correlation with serological and molecular tests to support or verify low reactive/positive test results.Methods: The serological test results of post-mortem corneal donors sent from the eye bank between January 2015 and December 2020 were analyzed retrospectively, and demographic and serological test data of these donors were obtained from ELISA laboratory data by the ISHOP system Cerrahpaca Medical Faculty Hospital.Results: Of 424 post-mortem corneal donors, 161 (37.7%) were female, and 263 (62.03) were male; 13 (3.06%) had high HBsAg positivity, 23 (5.42%) had low anti-HCV reactivity, 19 (4.48%) had low anti-HIV 1/2 reactivity, and two (0.47%) had high Tp-Ab IgG reactivity. Therefore, the corneas of a 30-year-old woman with positive HCV RNA result and 13 donors with high titer HBsAg positivity, and two donors with high reactivity in the Tp-Ab IgG test were not eligible for the Eye Bank after performing a real-time PCR assay for the confirmation of donors with low reactivity.Conclusion: We believe that it is essential to apply serological tests pre-keratoplasty to prevent infection transmission and perform confirmatory tests in low positivity/reactivity that may occur due to post-mortem coagulum hemolysis, within the framework of a collective and specific algorithm

Homologous or heterologous COVID-19 vaccine schemes: Comparison of immune responses and side effects

Real-life data are needed regarding the appropriate time and selection of vaccination strategies, homologous or heterologous. We aimed to compare neutralizing antibody levels and side effects in different vaccination schemes. The study included 310 Health Care Workers (HCWs) vaccinated with 5 different schemes. Antispike/RBD IgG levels were measured between 28 and 60 days after the last dose. Side effects in participants were recorded, and pharmacovigilance records were reviewed from the outpatient vaccine clinic. Mean age of the participants was 38 ± 11 years of whom 226 (72.9%) were female, and 84 (27.1%) were male. After booster doses, increasing antibody levels were detected in all groups. Mean antibody levels were detected to be statistically lower in 3 doses of inactivated vaccines group. The side effects were no significant difference between groups. Booster dose administration with mRNA vaccines stands out as the most accurate strategy for those at risk of contracting severe COVID-19 and HCWs caring for this population.IU-Cerrahpaşa Scientific Research Projects Uni