Antibody Response to COVID-19 Vaccines in Healthcare Workers: Which One is More Successful? Homologous or Heterologous?

Objectives: We aimed to determine the antibody levels created by COVID-19 vaccination in healthcare workers and the factors affecting the antibody response. Methods: Our research is a single-center, observational study that was prospectively designed and retrospectively analyzed at the beginning of the COVID-19 pandemic, and included 103 healthcare workers who received the three-dose regimen of COVID-19 vaccine. In accordance with the recommendations of the Ministry of Health of Turkey, the first two doses of CoronaVac vaccine were administered routinely, while the booster dose was given as BioNTech or CoronaVac (heterologous or homologous vaccination) depending on the preference of the volunteers. Antibody titers against the SARS-CoV-2 were measured in all individuals at different time points (1 month after the second dose of CoronaVac, before the booster dose [BioNTech or CoronaVac] at the fifth month and one month after the booster dose) with AESKULISA® SARS-CoV-2 S1 IgG (AESKU DIAGNOSTICS, Wendelsheim, Germany). Results: The mean age was 39.98±11.31 years, 62.1% of whom were women and 54.4% of them were accompanied by comorbid disease. After two doses of CoronaVac, the antibody titer averaged 49.50±33.15 U/mL in the 1st month (antibody seropositivity 86%) and the antibody titer decreased 24.01±33.48 U/mL (antibody seropositivity 49.5%) at 5th month. The mean antibody titer was found 59.73±60.20 U/ml in those who received the booster dose of homologous and 185.07±46.28 U/mL in those who were heterologous (p<0.001). Antibody levels were detected significantly lower after the booster dose of vaccination in patients with comorbidities (p<0.05). Conclusion: Our study, which reflects the data within the scope of the Turkey Ministry of Health's COVID-19 vaccination program determined that the antibody response after heterologous vaccination is better than in homologous vaccination. Antibody titer level in the 5th month was 50% waned after two doses of inactivated vaccination. It was also shown that factors such as gender, age, body mass index, and smoking did not create a statistically significant difference in homologous and heterologous vaccination, but after the booster dose antibody levels decreased significantly in those with comorbidity.

Changes in antimicrobial resistance and outcomes of health care-associated infections.

To describe the change in the epidemiology of health care-associated infections (HAI), resistance and predictors of fatality we conducted a nationwide study in 24 hospitals between 2015 and 2018. The 30-day fatality rate was 22% in 2015 and increased to 25% in 2018. In BSI, a significant increasing trend was observed for Candida and Enterococcus. The highest rate of 30-day fatality was detected among the patients with pneumonia (32%). In pneumonia, Pseudomonas infections increased in 2018. Colistin resistance increased and significantly associated with 30-day fatality in Pseudomonas infections. Among S. aureus methicillin, resistance increased from 31 to 41%.

A life-threatening brainstem compression by cerebral Echinococcus granulosus.

Cystic echinococcosis (CE) is a zoonotic disease caused by Echinococcus granulosus. It is of worldwide importance, and is widespread in the Mediterranean region and Middle East. This tapeworm shows great intraspecific variation in relation to host specificity, epidemiology and morphology. This variability led in previous years to the identification of ten (G1-G10) different genotypes of the parasite. Cerebral localization of E. granulosus is not common: it especially affects children and is more frequently located in the supratentorial region. It can be life-threatening due to its localization in eloquent areas especially in the posterior fossa. Despite the benign nature of hydatid cyst, invasion of critical areas may cause significant mortality and morbidity in some patients. Urgent surgical decompression and adjuvant medical treatment must be employed as soon as possible in these patients. We present a clinical case of life-threatening brainstem compression in a child due to a rare form of CE which was confirmed with biomolecular techniques. She presented with respiratory distress and progressive quadriparesis. All cysts were removed by microsurgical technique and albendazole was given postoperatively for one year with regular follow-ups.

West nile virus infection in the Mesopotamia region, Syria border of Turkey.

We described the serological prevalence of West Nile Virus (WNV) antibodies among the human population in a historical and strategic region of Turkey. A serologic survey was conducted based on suspected cases in April, 2009, in the Mesopotamia region of Turkey, in the villages that were located alongside the Zergan River. All the sera were tested by enzyme-linked immunosorbent assay ELISA (Euroimmune™), and the positive samples were tested by immunofluorescent assay (IFA; Euroimmune™). As confirmation, neutralizing antibodies against WNV were tested by microneutralization assay (MNTA). In total, 307 individuals were included. The MNTA test was found to be positive among 52 individuals out of 307 (17%). In multivariate analysis, age >50 [odds ratio (OR)=5.2, confidence interval (CI) 2.76-9.97, p<0.001) and being in an occupational risk group (OR=2.02, CI 1.02-4.04, p=0.044) were found to be the risk factors for WNV seropositivity with the MNTA test. The physicians in the region should be aware of the risk of WNV infection and should be alerted to detect the clinical cases.