Molecular characterization, phylogenetic and variation analyses of SARS-CoV-2 strains in Turkey.

Aims: We present the sequence and single-nucleotide polymorphism (SNP) analysis for 47 complete genomes for SARS-CoV-2 isolates on Turkish patients. Methods: The Illumina MiSeq platform was used for sequencing the libraries. The SNPs were detected by using Genome Analysis Toolkit - HaplotypeCaller v.3.8.0 and were inspected on GenomeBrowse v2.1.2. Results: All viral genome sequences of our isolates were located in lineage B under the different clusters, such as B.1 (n = 3), B.1.1 (n = 28) and B.1.9 (n = 16). According to the Global Initiative on Sharing All Influenza Data nomenclature, all of our complete genomes were placed in G, GR and GH clades. In our study, 549 total and 53 unique SNPs were detected. Conclusion: The results indicate that the SARS-CoV-2 sequences of our isolates have great similarity with all Turkish and European sequences.

The effectiveness of inactivated SARS-CoV-2 vaccine (CoronaVac) on antibody response in participants aged 65 years and older.

In this study, it was aimed to determine the antibody responses after the two doses of inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccinations in people who were above 65 years old and to evaluate the factors affecting this response. A total of 235 participants aged 65 years and older were included. Blood samples were taken and data about age, gender, comorbid diseases, and presence of side effects after vaccination were noted. Anti-SARS-CoV-2 QuantiVac ELISA (IgG) test kit (catalogue number: EI-2606-9601-10-G, Euroimmun) was used. The mean age was 70.38 ± 4.76. Approximately 120 of 235 participants had at least one comorbid disease. The mean levels of anti-SARS-CoV-2 IgG antibody after 4 weeks from the first and second doses of vaccine were 37.70 ± 57.08 IU/ml, and 194.61 ± 174.88 IU/ml, respectively. Additionally, 134 of 235 participants (57.02%) had under 25.6 IU/ml antibody level (negative) after 4 weeks from the first vaccine dose while this rate was 11.48% (n = 27) after 4 weeks from the second vaccine dose. The 19 (70.4%) participants who had under had 25.6 IU/ml antibody level after 4 weeks from the first dose of vaccine had at least one comorbid disease including diabetes mellitus, and 8 (29.6%) participants had no comorbid disease (F = 2.352, p = 0.006). Lower rates of antibody response were detected in participants aged 65 years and older and those with comorbidities both in our study and similar studies in the current literature. Further studies should evaluate whether the low antibody titers are really associated with age and comorbidities or not. Finally, prospective studies are needed to determine how long the immunity provided by SARS-CoV-2 vaccines will continue.

Prevalence of COVID-19 in 10,000 samples from 7853 patients in Eastern Turkey by positive real-time PCR.

Aim: COVID-19, caused by SARS-CoV-2, started in December 2019 and has spread across the world. Materials & methods: We analyzed real-time PCR results of 10,000 samples from 2 April to 30 May 2020 in three neighbor cities located in the East of Turkey. The final study population was 7853 cases, after excluding screening tests. Results: Real-time PCR was performed to detect the SARS-CoV-2-specific RNA-dependent-RNA-polymerase gene fragment. The number of total positive samples out of 7853 were 487; however, the number of nonrepeating positive patient was 373 (4.8%). Cough and fever were the most common symptoms in positive cases. Conclusion: Epidemiologic studies should be performed about the prevalence of SARS-CoV-2 infection to better understand the effect of the virus across the world.