Hacettepe health cohort (HU-CoVaCS): study design, baseline characteristics and the first 3-month-follow up of COVID-19 vaccinated students

Objective: This study included participants from Hacettepe University 4th, 5th, and 6th-grade students of Medical School and 4th and 5th-grade students of Dental School;and aimed to evaluate the general health status, COVID-19 history, vaccination status, and SARS-CoV-2 antibody levels of the participants to support their physical and social health, during the pandemic period. Methods: A prospective cohort study was conducted with an integrated, matched, nested case-control study. Sociodemographic characteristics, life habits, COVID-19 history, vaccination status, compliance with mask-distance-hygiene rules, and risks (if any) for COVID-19 were inquired via online questionnaires. Physical examinations, complete blood count, biochemistry tests, and anti-SARS-CoV-2 anti-spike antibody tests were conducted for all consenting participants. All analyses were established using depersonalized data. Results: Of the 778 participants completing the baseline visit in June-July 2021, the percentages of those vaccinated with at least one, two, and three/more doses of COVID-19 vaccine were 99.1%, 98.0%, and 11.7%, respectively;one had four doses. The median (minimum-maximum) time since the last vaccination was 134 (34-166) days for those vaccinated with two doses [CoronaVac (Sinovac Life Sciences, Beijing, China)] and 25 (14-56) days for those vaccinated with three doses [two doses of CoronaVac and a last dose of Pfizer-BioNTech mRNA vaccine (ComirnatyR). The third dose was applied at a median of 164 (151-202) days after the second dose, and all were heterologous in type. The median (minimum-maximum) antibody level for the overall group was 53.55(0-5680) BAU/mL: 47.19 BAU/mL in those who received two doses, with a more than 100 times increase after a third dose (4943.64 BAU/mL). Of the 522 participants followed up to October 1, 2021, 6 PCR-positive symptomatic participants were diagnosed with COVID-19: the incidence rate was 4/1000 person-months. Conclusion: A 100-fold neutralizing antibody level following the third dose demonstrated the importance of a booster dose. Given the time lag between doses, antibody measurements of BioNTech recipients should be repeated in the upcoming months. Booster selection should involve antibody level, variant sensitivity of the vaccine, and individual characteristics of the recipient.

Opinions of Infectious Diseases and Clinical Microbiology Physicians on Hospital Pandemic Management and Factors Influencing Reading the Pandemic Influenza National Preparedness Plan

Introduction: Infectious Diseases and Clinical Microbiology (IDCM) physicians have critical importance in terms of pandemic management in hospitals. There are recommendations for hospitals in the national pandemic preparedness plan, which was developed to limit the damage during pandemic periods. With this study, it was aimed to determine the reading status of IDCM physicians of the pandemic plan and the factors affecting it, and to learn their views on the application of the headings in the plan. Materials and Methods: For this descriptive study, the opinions of physicians were collected with an electronic questionnaire for the periods of June 2020 and January 2021. Statistical analyses were conducted to determine the associated factors of physicians' reading of the pandemic plan. Results: Of the 169 physicians participating in the study, 62.7% were women, with a mean age of 43.1 +/- 9.9 years, and nearly two-thirds of the physicians were working in a tertiary hospital. More than 70% of physicians read the pandemic preparedness plan. The rate of reading of the pandemic plan increased with the physician's time spent in IDCM practice [odds ratio (OR)=1.08, 95% confidence interval (CI)=1.01-1.16, p=0.037], and previous Coronavirus disease-2019 (COVID-19) experience (OR=3.10, 95% CI=1.00-9.58, p=0.050), and it decreased with the hand hygiene compliance of healthcare professional (OR=0.27, 95% CI=0.11-0.68, p=0.006) and the number of IDCM physicians working in the physician's hospital (OR=0.97, 95% CI=0.94-0.99, p=0.016). Conclusion: Physicians' reading status of the national pandemic preparedness plan did not differ significantly between the periods. As the time spent in IDCM practice and their pandemic experience before COVID-19 increased, the status of reading the pandemic plan increased. As the compliance with hand hygiene among the health professionals working in the physicians' hospital and the number of IDCM physicians increased it decreased. Attention should be paid to the introduction of the pandemic plan to physicians with professional inexperience and no pandemic experience.

Hacettepe Health Cohort (HU-CoVaCS): Study Design, Baseline Characteristics and the First 3-Month-Follow Up of COVID-19 Vaccinated Students.

Objective: This study included participants from Hacettepe University 4th, 5th, and 6th-grade students of Medical School and 4th and 5th-grade students of Dental School;and aimed to evaluate the general health status, COVID-19 history, vaccination status, and SARS-CoV-2 antibody levels of the participants to support their physical and social health, during the pandemic period. Method(s): A prospective cohort study was conducted with an integrated, matched, nested case-control study. Sociode-mographic characteristics, life habits, COVID-19 history, vaccination status, compliance with mask-distance-hygiene rules, and risks (if any) for COVID-19 were inquired via online questionnaires. Physical examinations, complete blood count, biochemistry tests, and anti-SARS-CoV-2 anti-spike antibody tests were conducted for all consenting partici-pants. All analyses were established using depersonalized data. Result(s): Of the 778 participants completing the baseline visit in June-July 2021, the percentages of those vaccinated with at least one, two, and three/more doses of COVID-19 vaccine were 99.1%, 98.0%, and 11.7%, respectively;one had four doses. The median (minimum-maximum) time since the last vaccination was 134 (34-166) days for those vaccinated with two doses [CoronaVac (Sinovac Life Sciences, Beijing, China)] and 25 (14-56) days for those vaccinated with three doses [two doses of CoronaVac and a last dose of Pfizer-BioNTech mRNA vaccine (Comirnaty). The third dose was applied at a median of 164 (151-202) days after the second dose, and all were heterologous in type. The median (minimum-maximum) antibody level for the overall group was 53.55(0-5680) BAU/mL: 47.19 BAU/mL in those who received two doses, with a more than 100 times increase after a third dose (4943.64 BAU/mL). Of the 522 participants followed up to October 1, 2021, 6 PCR-positive symptomatic participants were diagnosed with COVID-19: the incidence rate was 4/1000 person-months. Conclusion(s): A 100-fold neutralizing antibody level following the third dose demonstrated the importance of a booster dose. Given the time lag between doses, antibody measurements of BioNTech recipients should be repeated in the upcoming months. Booster selection should involve antibody level, variant sensitivity of the vaccine, and individual characteristics of the recipient.Copyright © 2023, DOC Design and Informatics Co. Ltd.. All rights reserved.

Back to the First Days of the Pandemic: How Well Have We Done to Diagnose COVID-19 in Healthcare Workers?

Introduction: Healthcare workers (HCWs) are one of the most vulnerable groups for COVID-19. SARS-CoV-2 PCR was offered to HCWs who had symptoms compatible with COVID-19 or who had a close contact with COVID-19 patient. A rapid antibody test was used to identify the risk of exposure of the HCWs who worked at high-risk units in our hospital during the first month of the pandemic. Herein, we aimed to evaluate the usefulness of this approach. Materials and Methods: The records of the HCWs from a university hospital who were tested by SARS-CoV-2 PCR or rapid antibody test between March 12, 2020 and April 04, 2020 were reviewed retrospectively. Demographic and clinical characteristics of HCWs were extracted from the electronic database. Wards or outpatient clinics that served COVID-19 patients were defined as high-risk units. Results: A total of 599 HCWs were tested for SARS-CoV-2 by PCR and 409 by rapid antibody test. Thirty-seven (6.2%) were found to be PCR positive. Eleven (29.7%) out of 37 HCWs were asymptomatic when they were tested. There was no statistically significant relationship between PCR positivity and occupation or working unit. A positive PCR result was detected in 24 HCWs during the first admission. Eleven out of 114 HCWs who were tested by a second PCR were found to be positive and two out of 17 HCWs who were tested by a third test were reported as PCR positive. Median interval between the first and second PCR was seven days (IQR= 8.5 days) and median interval between second and third PCR test was 4.5 days for the HCWs who were reported as positive at repeated PCR tests. Rapid antibody test was positive in one HCW who did not have a history of COVID-19. Conclusion: Approximately, one third of the SARS-CoV-2 PCR positive HCWs were asymptomatic. In case of increasing incidence of COVID-19 in the community, a regular screening policy for the HCWs regardless of their occupation and contact tracing might help to have a safe environment in hospitals. Screening policy should be based on well validated tests.

Neutralizing antibody response and associated factors in Coronavirus-19 disease (COVID-19) up to one month

Background: There is a knowledge gap about the characteristics of neutralizing antibody (NAb) response in patients who recovered COVID-19. In this study, it is aimed to elucidate the factors affecting the presence and titers of antibodies up to 30-days after onset. Material and methods: A total of 129 laboratory-confirmed COVID-19 patients were enrolled. Clinical data were obtained retrospectively. SARS-CoV-2 specific NAb, IgM, and IgG antibody responses were analyzed. Results: SARS-CoV-2 specific NAb, IgM and IgG, were detected at the time of hospital discharge in 60.5%, 30.2%, and 51.9% of the patients, respectively. The median time for obtaining serum samples for antibody tests after symptoms' onset was 11 days. The median titer of neutralizing antibody (SN50) was significantly higher in severe patients (25 vs. 7.5, p=0.009). Of the 23 severe patients, 52.2% (n=12) had higher NAb titers (i.e., SN50≥1:25) when compared to that in non-severe patients (OR=2.89;95%CI=1.15-7.28, p=0.021), yet, the potential effect of follow-up time on NAb status and titers could not be ruled out. Conclusions: The presence of antibody response is not the only determinative factor for recovery. The presence and higher titers of NAb were detected more in severe patients than their non-severe counterparts. Survival analysis suggested that this difference could at least be partially explained by the length of follow-up through antibody testing (at discharge) after symptoms' onset. © 2022 Aliye Bastug et al.