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.

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-naïve 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.

Different epidemiology of bloodstream infections in COVID-19 compared to non-COVID-19 critically ill patients: a descriptive analysis of the Eurobact II study.

BACKGROUND: The study aimed to describe the epidemiology and outcomes of hospital-acquired bloodstream infections (HABSIs) between COVID-19 and non-COVID-19 critically ill patients. METHODS: We used data from the Eurobact II study, a prospective observational multicontinental cohort study on HABSI treated in ICU. For the current analysis, we selected centers that included both COVID-19 and non-COVID-19 critically ill patients. We performed descriptive statistics between COVID-19 and non-COVID-19 in terms of patients' characteristics, source of infection and microorganism distribution. We studied the association between COVID-19 status and mortality using multivariable fragility Cox models. RESULTS: A total of 53 centers from 19 countries over the 5 continents were eligible. Overall, 829 patients (median age 65 years [IQR 55; 74]; male, n = 538 [64.9%]) were treated for a HABSI. Included patients comprised 252 (30.4%) COVID-19 and 577 (69.6%) non-COVID-19 patients. The time interval between hospital admission and HABSI was similar between both groups. Respiratory sources (40.1 vs. 26.0%, p < 0.0001) and primary HABSI (25.4% vs. 17.2%, p = 0.006) were more frequent in COVID-19 patients. COVID-19 patients had more often enterococcal (20.5% vs. 9%) and Acinetobacter spp. (18.8% vs. 13.6%) HABSIs. Bacteremic COVID-19 patients had an increased mortality hazard ratio (HR) versus non-COVID-19 patients (HR 1.91, 95% CI 1.49-2.45). CONCLUSIONS: We showed that the epidemiology of HABSI differed between COVID-19 and non-COVID-19 patients. Enterococcal HABSI predominated in COVID-19 patients. COVID-19 patients with HABSI had elevated risk of mortality. Trial registration ClinicalTrials.org number NCT03937245 . Registered 3 May 2019.

Comparison of SARS-CoV-2 Antibody Levels after a Third Heterologous and Homologous BNT162b2 Booster Dose.

This study aimed to determine the anti-S (receptor binding protein) RBD IgG antibody titers formed against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) and the neutralizing antibody inhibition percentages (nAb IH%) in blood samples taken after two doses of inactive or mRNA-based vaccine and a booster dose. Volunteers with two doses of inactivated CoronaVac (heterologous group; n = 75) and BioNTech (BNT)162b2 mRNA vaccine (homologous group; n = 75) were included in this study. All participants preferred the BNT162b2 vaccine as a booster dose. First, peripheral blood samples were taken 3 months after the second vaccine dose. Second, peripheral blood samples were taken 1 month after the booster dose. Anti-S-RBD IgG titers were determined by CMIA (SARS-CoV-2 IgG II Quant). Neutralizing antibodies were detected by a surrogate neutralization assay (SARS-CoV-2 NeutraLISA, Euroimmun, Lübeck, Germany). The median age of the volunteers was 40 (IQR 29-47) years old. After the heterologous booster dose, anti-S-RBD IgG levels and neutralizing antibodies increased approximately 50-fold and 9-fold, respectively. Anti-S-RBD IgG titers increased by 9 and 57 times, respectively, while nAb IH% increased by 1.5 and 16 times, respectively, among those with heterologous reminder doses and those with and without a prior history of coronavirus disease (COVID-19). This study showed that after the administration of a heterologous booster dose with BNT162b2 to those whose primary vaccination was with inactivated CoronaVac, the binding and neutralizing antibody levels were similar to those who received a homologous BNT162b2 booster dose. It was observed that the administration of heterologous and homologous booster doses resulted in the development of similar levels of neutralizing antibodies, independently from a prior history of COVID-19.

Association of SARS-CoV-2 IgG Antibody Levels with Clinical/Laboratory Characteristics in COVID-19 Patients: Data from a Turkish Study.

BACKGROUND: COVID-19 causes clinical manifestations ranging from asymptomatic infection to multi-organ failure. It is reported that those with severe disease have higher anti-SARS-CoV-2 antibody titers compared to asymptomatic or mild cases. We evaluated the correlation of antibody responses with laboratory and clinical indicators in COVID-19 patients. METHODS: Seventy-nine male and 66 female patients (mean age: 39) with at least one positive SARS-CoV-2 RT-PCR test and SARS-CoV-2 IgG antibody result after acute infection were included. RESULTS: Seventy-six (52%), 45 (31%), and 24 (17%) patients had mild, moderate, and severe clinical findings, respectively. Patients with high body mass index and advanced age had significantly more severe disease (p < 0.001). A significant correlation was found between the increase in lymphopenia, C-reactive protein, ferritin, D-dimer, and lactate dehydrogenase and the severity of clinical findings (p = 0.0001). SARS-CoV-2 IgG antibody test was positive in 128 (88.3%) patients. A significant correlation was found between disease severity and antibody levels in the comparison of all groups (p < 0.001). CONCLUSIONS: Long-term monitoring of immune responses will be required to determine the appropriate time for the administration of new vaccines.

Incidence, Risk Factors, and Prognosis of Bloodstream Infections in COVID-19 Patients in Intensive Care: A Single-Center Observational Study.

BACKGROUND: Critically ill COVID-19 patients are prone to bloodstream infections (BSIs). AIM: To evaluate the incidence, risk factors, and prognosis of BSIs developing in COVID-19 patients in the intensive care unit (ICU). METHODS: Patients staying at least 48 h in ICU from 22 March 2020 to 25 May 2021 were included. Demographic, clinical, and laboratory data were analyzed. RESULTS: The median age of the sample (n = 470) was 66 years (IQR 56.0-76.0), and 64% were male. The three most common comorbidities were hypertension (49.8%), diabetes mellitus (32.8%), and coronary artery disease (25.7%). Further, 252 BSI episodes developed in 179 patients, and the BSI incidence rate was 50.2 (95% CI 44.3-56.7) per 1000 patient-days. The source of BSI is central venous catheter in 42.5% and lower respiratory tract in 38.9% of the episodes. Acinetobacter baumannii (40%) and carbapenem-resistant Klebsiella pneumoniae (21%) were the most common pathogens. CRP levels were lower in patients receiving tocilizumab. Multivariable analysis revealed that continuous renal replacement therapy, extracorporeal membrane oxygenation, and treatment with a combination of methylprednisolone and tocilizumab were independent risk factors for BSI. The estimated cumulative risk of developing first BSI episode was 50% after 6 days and 100% after 25 days. Of the 179 patients, 149 (83.2%) died, and a statistically significant difference (p < 0.001) was found in the survival distribution in favor of the group without BSI. CONCLUSION: BSI is a common complication in COVID-19 patients followed in the ICU, and it can lead to mortality. Failure in infection control measures, intensive immunosuppressive treatments, and invasive interventions are among the main factors leading to BSIs.

Waning effectiveness of CoronaVac in real life: A retrospective cohort study in health care workers.

BACKGROUND: Real-world studies showed varying levels of effectiveness of CoronaVac vaccine against COVID-19 disease. This study aimed to assess the association between the vaccination with CoronaVac and the COVID-19 infections among the health care workers in a university hospital and to determine the vaccine effectiveness against COVID-19 in a period when alpha variant was dominant. METHODS: This retrospective cohort study was conducted in a university hospital in Istanbul, Turkey employs 4067 health care workers. The follow-up period was defined as starting 14 days after receiving the second dose for fully vaccinated group. Health care workers were censored when have a positive PCR test result or at the end of the study. Unvaccinated health care workers were censored if they receive any COVID-19 vaccine doses. The incidence rate ratio and Cox regression were used to estimate the unadjusted and adjusted effectiveness of the vaccine. FINDINGS: Seventy-one percent of the health care workers were fully vaccinated whereas 29% percent did not receive any doses. The incidence rate of SARS-CoV-2 infection was 133.7 vs 70.7 per 100.000 person-days in the unvaccinated and fully vaccinated groups, respectively. The unadjusted effectiveness against COVID-19 infection was 47% (95% CI 31-59%) whereas adjusted effectiveness was 39% (95% CI 20-64%). INTERPRETATION: This real life study conducted in health care workers demonstrated that the effectiveness of two doses of the CoronaVac vaccine (39%) was lower than that determined in clinical trials. Due to reduce in protection over time or against variants, booster doses may be needed.

Antibody responses to inactivated SARS-CoV-2 vaccine in peritoneal dialysis patients.

INTRODUCTION: As end-stage renal disease (ESRD) patients generally have reduced responses to the vaccines, effectiveness of newly developed SARS-CoV-2 vaccines in ESRD are also matters of curiosity. We aimed to investigate the humoral responses of our peritoneal dialysis (PD) patients to the inactivated SARS-CoV-2 vaccine. METHODS: Humoral immune responses of 23 PD patients who received two doses of the inactivated SARS-CoV-2 vaccine were investigated with a commercial test that measures IgG antibodies towards receptor binding domain of SARS-CoV-2 spike protein. Seropositivity rates, antibody titers, and ESRD related clinical data were compared with 51 hemodialysis (HD) patients and 29 healthy volunteers. RESULTS: Seropositivity of PD patients with the inactivated vaccine was 95.6%. Both the rate of seropositivity and SARS-CoV-2 IgG antibody levels in PD patients were not different from the healthy controls (p = 0.85 and 0.19, respectively). While seropositivity rates were not different for PD or HD patients (p = 0.09), the magnitude of humoral responses was significantly higher in PD patients (p = 0.0001). There were no vaccine-related serious adverse events. In the 3-months clinical follow-up, none of the patients experienced SARS-CoV-2 infection. CONCLUSION: Two doses of the inactivated vaccine generate adequate humoral immune response in PD patients without any serious adverse events.

Inactive SARS-CoV-2 vaccine generates high antibody responses in healthcare workers with and without prior infection.

BACKGROUND AND OBJECTIVES: Healthcare workers (HCWs) were among the first groups to be vaccinated in Turkey. The data to be obtained by the vaccination of HCWs would guide wide spread vaccination programs. MATERIALS AND METHODS: The study included 330 HCWs working at Istanbul University-Cerrahpasa, Cerrahpasa Medical Faculty Hospital and vaccinated with inactive CoronaVac (Sinovac Life Sciences, China) SARS-CoV-2 vaccine in two doses (28 days apart). Anti-Spike /RBD IgG levels were measured 14 days after the first dose and 28 days after the second dose. Chemiluminescent microparticle immunoassay (CMIA) (ARCHITECT IgG II Quant test, Abbott, USA), which is 100% compatible with plaque reduction neutralization test (PRNT), was used. RESULTS: Of the participants, 211 (63.9%) were female, 119 (36.1%) were male, and mean age was 39.6 ± 7.7 years. In those without prior COVID-19 history; (n = 255) antibody positivity was detected as 48.2% (95% CI: 42.1-54.3) 14 days after the first dose of vaccine, and 99.2% (95% CI: 98.1-100) at day 28 after the second dose. Antibody titers were significantly lower in patients with hypertension (p = 0.011). In those with prior history of COVID-19 (n = 75); both the antibody positivity rates after the first vaccine (48.2% vs 100%, p = 0.000) and the anti-spike/RBD antibody levels after the second vaccine (with a ≥ 1050 AU/mL titer equivalent to PRNT 1/80 dilution) was significant than infection-naive group (25.9% vs. 54.7%, p = 0.000). Antibody positivity after two doses of vaccination for all study group was 99.4% (95% CI: 98.6-100). CONCLUSIONS: Two doses CoronaVac produce effective humoral immunity in HCWs. Antibody response is significantly higher in those with prior history of COVID-19 than infection-naive group. Given no significant benefit of the second dose, a single shot of vaccination may be sufficient for those with prior history of COVID-19. Monitoring humoral and cellular immune responses, considering new variants, is required to validate this approach.

COVID-19 Vaccine Hesitancy in Healthcare Personnel: A University Hospital Experience.

Healthcare workers are among risk groups in the COVID-19. Even if they are not infected with the disease, they witness the effects of the pandemic. The aim of the study is to determine the factors affecting COVID-19 vaccination status and reasons for vaccine hesitancy of healthcare personnel in our hospital. Firstly, the vaccination status and demographic characteristics of all healthcare personnel was evaluated. After that, a survey was applied to 408 vaccinated and 297 nonvaccinated personnel. Within the first month after the beginning of vaccination, 66% of 3937 healthcare personnel received a COVID-19 vaccine. The number of vaccinated personnel was higher among doctors, master graduates or higher educational levels and basic science-laboratory unit workers. In the surveyed group, being under the age of 50 (OR:1.85), being nondoctor healthcare personnel (nurse/midwife OR:1.78, administrative personnel OR:3.42, patient attendant/cleaning staff OR:4.11, security guard/other OR:2.96), having had the disease before (OR:2.36), not having the flu vaccine (OR:3.24) and hesitancy about other vaccines (OR:6.61) were found to be independent risk factors for not having a COVID-19 vaccine or having it late. The three most common reasons for not getting vaccinated were doubt on the efficacy of the vaccine, distrust of its content, and fear of side effects. Taking steps by considering the main factors of hesitancy among healthcare personnel will increase the vaccine acceptance.

[Clinical Characteristics of Mild-Moderate COVID-19 Patients and Risk Factors for the Development of Pneumonia]. / Hafif-Orta Klinik Seyirli COVID-19 Hastalarinin Genel Özellikleri ve Pnömoni Gelisimi için Risk Faktörler.

Limited data exists to date on the predictors for the development of pneumonia in patients with mild and moderate coronavirus (COVID-19). In this study, it was aimed to evaluate the demographic characteristics and clinical findings of mild and moderate COVID-19 and to determine the risk factors for the development of COVID-19 pneumonia in patients admitted to the pandemic outpatient clinic of a university hospital. A total of 414 patients with laboratory confirmed COVID-19 were included. Of these, 220 (53.1%) were male, the mean age was 38.3 ± 12.7. Median duration of hospital admission from the onset of symptoms was three days (0-11). Of the confirmed COVID-19 cases, 154 (37.2%) had a history of family contact and the most common symptoms were weakness (68.4%), myalgia (61.8%), headache (56.5%), loss of smell (45.2%), loss of taste (43.2%) and anorexia (42.8%). Among females, weakness (p= 0.016), headache (p= 0.008), sore throat (p= 0.032), nausea (p= 0.003), anorexia (p= 0.045), loss of taste (p= 0.005) and loss of smell (p<0.001) were more common. Loss of taste (47.6% vs. 25%, p<0.001) and loss of smell (50% vs. 26.3%, p<0.001) were more common in patients with under the age of 50 and cough (43.4% vs. 29.3%, p= 0.003) was more common in patients with above the age of 40. Among 46 (11.1%) patients with asymptomatic COVID-19, there was no significant difference (p= 0.500) between the genders. Pneumonia was detected in 150 (43.8%) of 339 patients who underwent thorax computed tomography. In the univariate analysis; advanced age (p<0.001, odds ratio (OR)= 1.44), obesity (p<0.001 OR= 2.5), not being actively smoking (p<0.001, OR= 6.19), fever at first admission (p= 0.002, OR= 2.02), cough (p<0.001, OR= 3.26), shortness of breath (p<0.001, OR= 23.37), weakness (p= 0.042, OR= 1.63), anorexia (p= 0.009, OR= 1.79) and elevation of D-dimer (p= 0.014, OR= 1.92) were associated with the development of pneumonia. In multivariate analysis, obesity (p= 0.005, OR= 2.69), not being actively smoking (p<0.001, OR= 5.43), cough at first admission p= 0.017, OR= 2.16) and shortness of breath (p= 0.008, OR= 16.22) was determined as an independent risk factor for the development of pneumonia. CRP (p<0.001), D-dimer (p<0.001), ferritin (p<0.001) values among 108 (26.1%) patients with a body-mass index(BMI) >30 were high, and 60.9% of the patients had pneumonia (p<0.001) . CRP (p<0.001), D-dimer (p= 0.010) values were low, lymphocyte count (p= 0.001) was high among 106 (25.6%) active smokers, and 15.6% of the patients had pneumonia (p<0.001). Of the patients reported with persistent symptoms, 25.9% had loss of smell, 25% had weakness, and 23.1% had loss of taste on the seventh day; 21.1% had loss of smell, 21.1% had myalgia, and 19.7% had loss of taste on the 14th day. During their follow-up, the COVID-19 polymerase chain reaction (PCR) test was studied in 286 patients for control purposes. The median time of being negative for COVID-19 PCR test was eight days (3-56). In conclusion, symptoms may last longer than 14 days in 20- 30% of patients presenting with mild-moderate clinical findings. In addition, obesity should be considered as an important risk factor for COVID-19 pneumonia.

Antibody response to inactivated COVID-19 vaccine (CoronaVac) in immune-mediated diseases: a controlled study among hospital workers and elderly.

OBJECTIVE: To assess antibody response to inactivated COVID-19 vaccine in patients with immune-mediated diseases (IMD) among hospital workers and people aged 65 and older. METHODS: In this cross-sectional study, we studied 82 hospital workers with IMD (mean age: 42.2 ± 10.0 years) and 300 (mean age: 41.7 ± 9.9 years) controls. Among + 65 aged population, we studied 22 (mean age: 71.4 ± 4.5 years) patients and 47 controls (mean age: 70.9 ± 4.8 years). All study subjects had a negative history for COVID-19. Sera were obtained after at least 21 days following the second vaccination. Anti-spike IgG antibody titers were measured quantitatively using a commercially available immunoassay method. RESULTS: Patients with IMD were significantly less likely to have detectable antibodies than healthy controls both among the hospital workers (92.7% vs 99.7%, p < 0.001) and elderly population (77.3% vs 97.9%, p = 0.011). Among patients with IMD, those using immunosuppressive or immune-modulating drugs (64/75, 85.3%) were significantly less likely to have detectable antibodies compared to those off treatment (29/29, 100%) (p = 0.029). Additionally, a negative association between age and the antibody titer categories among patients (r = - 0.352; p < 0.001) and controls (r = - 0.258; p < 0.001) were demonstrated. CONCLUSIONS: Among hospital workers, the vast majority of patients with IMD and immunocompetent controls developed a significant humoral response following the administration of the second dose of inactivated COVID-19 vaccine. This was also true for the elderly population, albeit with lower antibody titers. Immunosuppressive use, particularly rituximab significantly reduced antibody titers. Antibody titers were significantly lower among those aged ≥ 60 years both in patient and control populations. Whether these individuals should get a booster dose warrants further studies.