Nasal irrigation is thought to decrease the viral load present in the nasal cavity. Our aim was to assess the effect of a hypertonic seawater solution [with algal and herbal natural ingredients (Sinomarin^®)] on the viral load of nasopharynx in patients hospitalized with severe COVID-19 pneumonia. We conducted a prospective, randomized, controlled trial from June 2022 to December 2022. We allocated 56 patients with COVID-19 pneumonia into two groups (28 in each group)—the hypertonic seawater group [nasal irrigations with a hypertonic seawater solution (Sinomarin^®) every 4 h for 16 h per day, for two consecutive days] and the control group (no nasal irrigations). A second nasopharyngeal swab was collected 48 h after the baseline nasopharyngeal swab (8 h after the last wash in the hypertonic seawater group) to estimate the SARS-CoV-2 viral load as determined by cycle threshold (Ct) values. In the hypertonic seawater group, the mean Ct values significantly increased two days after the initial measurement [ΔCt 48−0 h = 3.86 ± 3.03 cycles, p < 0.001 (95%CI: 2.69 to 5.04)]. No significant differences in the Ct values were observed in the control group [ΔCt 48−0 h = −0.14 ± 4.29, p = 0.866 (95%CI: −1.80 to −1.52)]. At follow-up, 17 patients from the hypertonic seawater group had negative test results compared to only 9 patients from the control group (p = 0.03). Nasal irrigations with a hypertonic seawater solution containing algal and herbal natural ingredients significantly decreased nasopharyngeal viral load and the detection time of SARS-CoV-2 in the nasal cavity.

Background: We aimed to estimate the SARS-CoV-2 antigen and antibody seroprevalence in one of the worst-affected by the pandemic semi-closed communities in Greece, Deskati, and evaluate the sociodemographic and clinical correlations of functional antibody responses. Methods: The Ag2019n-CoV V1310/V1330 Rapid Test (Prognosis Biotech, Greece) was used for antigen detection. The Rapid Test 2019-nCoV Total Ig, V1210/V1230 (Prognosis Biotech, Greece), and the SARS-CoV-2 IgG II Quant method (Architect, Abbott, Illinois, USA) were used for antibody testing. Results: None of the participants had a positive antigen result. SARS-CoV-2 seropositivity ranged from 13% to 45% in the study population, depending on the method. One-third of the participants with known past infection had a positive antibody test result 77 ± 13 days after infection. Two-fifths of infections determined by serology were asymptomatic. The advancing age and hospitalization predicted seropositivity among patients with past infection. Half of the participants who tested positive for antibodies were not aware of past infection. Conclusions: High-burden contexts in Greece, such as Deskati, are not so far from herd immunity thresholds. We highlighted the value of low-cost serosurveys targeting both symptomatic and asymptomatic populations to evaluate the natural immune response to SARS-CoV-2 in nonvaccinated susceptibles and design evidence-based policies for lifting lockdowns.

Background. Although great progress has been made over the past 2 years in the scientific understanding of the biology, epidemiology, and pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), case morbidity and fatality rates remain a great concern and continue to challenge the healthcare resources worldwide as novel variants emerge. There is therefore an urgent need for affordable and readily available strategies to reduce viral transmission. Previous studies in non-COVID-19 patients have demonstrated that administration of low-salt (isotonic but 0.0375% Na) and isotonic saline (0.9% Na) solutions has been associated with an immediate, significant reduction in the microbial antigens and a related decline of microbial burden. The aim of the present study was to determine the effect of nasal washes with normal saline 0.9% on nasopharyngeal viral load and outcome in hospitalized patients with COVID-19 pneumonia. Methods. We performed a prospective, randomized, pilot, controlled trial in 50 patients with confirmed COVID-19 disease. Patients were randomized into two groups, the normal saline group (received normal saline 0.9% solution for nasopharyngeal wash) and the control group (no treatment). In the normal saline group, nasopharyngeal wash was performed every 4 hours for a 16-hour period. Twenty-four hours after the baseline nasopharyngeal swab (and 8 hours after the last wash in the normal saline group), a second nasopharyngeal swab was collected for the semiquantitative estimation of the SARS-CoV-2 viral load as determined by cycle threshold (Ct) values. Results. In the normal saline group, mean N gene Ct values increased significantly 24 hours after the baseline measurement [ΔCt_day2−day1 = 1.87 ± 3.11 cycles, (95% CI: 0.55 to 3.18)], indicating a decline in SARS-CoV-2 nasopharyngeal viral load by 8.9%. A significant decrease in mean N gene Ct values was observed in the control group, indicating an increase in viral load [ΔCt_day2-day1 = −2.12 ± 2.66, (95% CI: −3.20 to −1.05)] by 9.7%. The difference between the two groups 24 hours after admission and nasopharyngeal wash was 3.09 cycles ( , 95% CI: 0.97 to 5.20). Conclusion. Nasal washes with normal saline effectively decreased the viral load during hospitalization and at follow-up.

Background: Both SARS-CoV-2 infection and/or vaccination result in the production of SARS-CoV-2 antibodies. We aimed to compare the antibody titers against SARS-CoV-2 in different scenarios for antibody production. Methods: A surveillance program was conducted in the municipality of Deskati in January 2022. Antibody titers were obtained from 145 participants while parallel recording their infection and/or vaccination history. The SARS-CoV-2 IgG II Quant method (Architect, Abbott, IL, USA) was used for antibody testing. Results: Advanced age (>56 years old) was associated with higher antibody titers. No significant differences were detected in antibody titers among genders, BMI, smoking status, comorbidities, vaccine brands, and months after the last dose. Hospitalization length and re-infection were predictors of antibody titers. The individuals who were fully or partially vaccinated and were also double infected had the highest antibody levels (25,017 ± 1500 AU/mL), followed by people who were fully vaccinated (20,647 ± 500 AU/mL) or/partially (15,808 ± 1800 AU/mL) vaccinated and were infected once. People who were only vaccinated had lower levels of antibodies (9946 ± 300 AU/mL), while the lowest levels among all groups were found in individuals who had only been infected (1124 ± 200 AU/mL). Conclusions: Every hit (infection or vaccination) gives an additional boost to immunization status.

Previous studies have demonstrated that a cumulative dose of methylprednisolone more than 200 mg could suppress the immune cells resulting in prolonged severe acute respiratory syndrome coronavirus 2 shedding in patients with coronavirus disease 2019 (COVID-19) pneumonia

Background: In this work, we aimed to evaluate antibody-response longevity to SARS-CoV-2 infection and/or vaccination in one of the Greek communities that was worst hit by the pandemic, Deskati, five months after a previous serosurveillance and nine months after the pandemic wave initiation (October 2020). Methods: The SARS-CoV-2 IgG II Quant method (Architect, Abbott, IL, USA) was used for antibody testing. Results: A total of 69 subjects, who previously tested positive or negative for COVID-19 antibodies, participated in the study. We found that 48% of participants turned positive due to vaccination. 27% of participants were both previously infected and vaccinated. However, all previously infected participants retained antibodies to the virus, irrespective of their vaccination status. The antibody titers were significantly higher in previously infected participants that had been vaccinated than those who were unvaccinated and in those that had been previously hospitalized for COVID-19 than those with mild disease. Conclusions: Antibody responses to SARS-CoV-2 infection were maintained nine months after the pandemic. Vaccination alone had generated an immune response in almost half of the population. Higher antibody titers were found in the case of vaccination in previously infected subjects and especially in those with severe disease leading to hospitalization.