GSGeorge Sourvinos

George Sourvinos

*This is an algorithmically generated author record based on publicly available information.

Current Organizations / Institutes

The organizations/institutes from the scholar's latest article

Previous Organizations / Institutes

The organizations / institutes from the scholar's other articles in the past ten years


George Sourvinos has a total of 188 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Seroepidemiological Observational Study in Total and Neutralizing Antibodies to SARS-CoV-2 Among Primary Care Patients in Crete, Greece

    by Zoi Pournara, Emmanouela Kissandraki, Sevasti Koursioti, Manolis Linardakis, Emmanouil K. Symvoulakis, Marilenna Anastasaki, Christos D. Lionis, George Sourvinos

    The current study aimed to assess the levels of total IgG antibodies against the spike (S) and nucleocapsid (N) proteins of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as the neutralizing antibodies (nAbs) in a population of Crete, Greece. In total, 1,061 participants with 2,081 follow-up measurements during May-December 2022, from eight different primary healthcare facilities, were categorized into four groups, based on vaccination and illness status. Blood samples were collected and processed to measure anti-S, anti-N and neutralizing antibodies. Based on specific cutoff values and using non-parametric methods, antibody levels were compared between different categories or disease/vaccination of SARS-CoV-2. The proportion of participants who had been infected was higher among the unvaccinated. Additionally, an increase in the number of vaccine doses administered resulted in a noteworthy reduction in the frequency of illness, with proportions decreasing from 69.2% among those who were not vaccinated or 83.1% among those vaccinated 1-2 times to 21.6% among those vaccinated 4+ times (pvs. 83.27, p<0.001). This population-based seroepidemiological study underscores the synergistic impact of vaccination and natural infection in sustaining elevated antibody levels during the Omicron period. The findings emphasize the importance of continuous immunological surveillance within primary healthcare settings to identify individuals at risk of declining immunization and to inform evidence-based booster vaccination strategies, thereby enhancing preparedness and resilience against future pandemic responses.

  • Open Access

    A Mixture of Essential Oils from Three Cretan Aromatic Plants Inhibits SARS-CoV-2 Proliferation: A Proof-of-Concept Intervention Study in Ambulatory Patients

    by Christos Lionis, Elena Petelos, Manolis Linardakis, Athanasios Diamantakis, Emmanouil Symvoulakis, Maria-Nefeli Karkana, Marilena Kampa, Stergios A. Pirintsos, George Sourvinos, Elias Castanas

    Introduction: The need for effective therapeutic regimens for non-critically ill patients during the COVID-19 pandemic remained largely unmet. Previous work has shown that a combination of three aromatic plants’ essential oils (CAPeo) (Thymbra capitata (L.) Cav., Origanum dictamnus L., Salvia fruticose Mill.) has remarkable in vitro antiviral activity. Given its properties, it was urgent to explore its potential in treating mild COVID-19 patients in primary care settings. Methods: A total of 69 adult patients were included in a clinical proof-of-concept (PoC) intervention study. Family physicians implemented the observational study in two arms (intervention group and control group) during three study periods (IG2020, n=13, IG2021/22, n=25, and CG2021/22, n=31). The SARS-CoV-2 infection was confirmed by real-time PCR. The CAPeo mixture was administered daily for 14 days per os in the intervention group, while the control group received usual care. Results: The PoC study found that the number and frequency of general symptoms, including general fatigue, weakness, fever, and myalgia, decreased following CAPeo administration. By Day 7, the average presence (number) of symptoms decreased in comparison with Day 1 in IG (4.7 to 1.4) as well as in CG (4.0 to 3.1), representing a significant decrease in the cumulative presence in IC (−3.3 vs. −0.9, p < 0.001; η2 = 0.20) on Day 7 and on Day 14 (−4.2 vs. −2.9, p = 0.027; η2 = 0.08). Discussion/Conclusions: Our findings suggest that CAPeo possesses potent antiviral activity against SARS-CoV-2 in addition tο its effect against influenza A and B and human rhinovirus HRV14 strains. The early and effective impact on alleviating key symptoms of COVID-19 may suggest this mixture can act as a complementary natural agent for patients with mild COVID-19.


  • Open Access

    A mixture of essential oils from three Cretan Aromatic Plants inhibits SARS-CoV-2 proliferation: A Proof-of-Concept intervention study in ambulatory patients

    by Christos Lionis, Elena Petelos, Manolis Linardakis, Athanasios Diamantakis, Emmanouil Symvoulakis, Maria-Nefeli Karkana, Marile Kampa, Stergios A Pirintsos, George Sourvinos, Elias Castanas

    Introduction: The need for therapeutic regimens for non-critically ill patients during the COVID-19 pandemic remains unmet. Previous work has shown that a combination of three aromatic plants’ essential oil (CAPeo) (Thymbra capitata (L.) Cav., Origanum dictamnus L., Salvia fruticosa Mill.) has remarkable in vitro antiviral activity. Given its properties, it was urgent to explore its potential in treating mild COVID-19 patients in primary care. Methods: 69 adult patients were included in a clinical, Proof-of-Concept (PoC) intervention study. Family physicians implemented the observational study in two arms (intervention and control group) during three study periods (IG2020, n=13, IG2021/22, n=25 and CG2021/22, n=31). The SARS-CoV-2 infection was confirmed by real-time PCR. The CAPeo mixture, was administered daily for 14 days, per os in the intervention group, while the control group received usual care. Results: The PoC study, found that the number and frequency of general symptoms, including general fatigue, weakness, fever and myalgia, decreased following CAPeo administration. The average presence (number) of symptoms decreased in IG (4.7 to 1.4) as well as in CG (4.0 to 3.1) by Day 7 compared to Day 1, representing a significant decrease in cumulative presence in IC (-3.3 vs. -0.9, p<0.001; η2=0.20) on Day 7 and on Day 14 (-4.2 vs. -2.9, p=0.027; η2=0.08). Discussion/Conclusion: Our findings suggest that CAPeo, possesses potent antiviral activity, in addition tο the Influenza A and B and the human rhinovirus HRV14 strains against SARS-CoV-2. The early and effective impact in alleviating key symptoms of COVID-19 may suggest this mixture can act as a complementary natural agent for mild COVID-19 patients


  • Open Access

    Overview of Mpox Outbreak in Greece in 2022–2023: Is It Over?

    by Kassiani Mellou, Kyriaki Tryfinopoulou, Styliani Pappa, Kassiani Gkolfinopoulou, Sofia Papanikou, Georgia Papadopoulou, Evangelia Vassou, Evangelia-Georgia Kostaki, Kalliopi Papadima, Elissavet Mouratidou, et al.

    In May 2022, for the first time, multiple cases of mpox were reported in several non-endemic countries. The first ever case of the disease in Greece was confirmed on 8 June 2022, and a total of 88 cases were reported in the country until the end of April 2023. A multidisciplinary response team was established by the Greek National Public Health Organization (EODY) to monitor and manage the situation. EODY’s emergency response focused on enhanced surveillance, laboratory testing, contact tracing, medical countermeasures, and the education of health care providers and the public. Even though management of cases was considered successful and the risk from the disease was downgraded, sporadic cases continue to occur. Here, we provide epidemiological and laboratory features of the reported cases to depict the course of the disease notification rate. Our results suggest that measures for raising awareness as well as vaccination of high-risk groups of the population should be continued.


  • Open Access

    Overview of Mpox outbreak in Greece in 2022-2023; Is it over?

    by Kassiani Mellou, Kyriaki Tryfinopoulou, Styliani Pappa, Kassiani Gkolfinopoulou, Sofia Papanikou, Georgia Papadopoulou, Evaggelia Vassou, Evaggelia- Georgia Kostaki, Kalliopi Papadima, Elissavet Mouratidou, et al.

    In Μay 2022, for the first time, multiple cases of mpox were reported in several non-endemic countries. The first ever case of the disease in Greece was confirmed on 8 June 2022 and a total of 88 cases were reported in the country until the end of April 2023. A multidisciplinary response team was established by the Greek National Public Health Organization (EODY) to monitor and manage the situation. EODY’s emergency response focused on enhanced surveillance, laboratory testing, contact tracing, medical countermeasures, and education of health care providers and the public. Even though management of cases was considered successful and the risk from the disease was down-graded, sporadic cases continue to occur. Here, we provide epidemiological and laboratory features of the reported cases to depict the course of the disease notification rate, that suggests measures for raising awareness as well as vaccination of high-risk groups of the population should be continued.


  • Comparison of two point-of-care respiratory panels for the detection of influenza A/B virus

    by Alexandros Zafiropoulos, Aspasia Dermitzaki, Nikos Malliarakis, Marina Stamataki, Maria Ergazaki, Evangelia Xenaki, Maria-Eleni Parakatselaki, George Sourvinos

    Rapid and accurate diagnostics of patients with suspected seasonal influenza or pathogens of the upper respiratory tract is crucial. Fast detection is important especially for influenza A/B virus, so that isolation measures should be taken to prevent the spread of the virus. We compared the performance of two syndromic testing methodologies (QIAstat-Dx RP, BioFire RP2plus) against the Alere™ i as the comparator method. Totally, 97 swab samples were included from patients with symptoms of acute respiratory infection admitted in the hospitals of the wider region of Crete, Greece. The Positive Percent Agreement (PPA) of the BioFire RP2plus was 100% (95% CI 87.66%-100%), while the Negative Percent Agreement (NPA) was estimated at 91.3% (95% CI 82.03%-96.74%). This method produced no invalid results. For QIAstat-Dx RP the PPA was 89.29% (95% CI 71.77%-97.73%), while the NPA was 91.3% (95% CI 82.03%-96.74%, 63/69). The BioFire RP2plus managed to determine the subtype in more samples than the QIAstat-Dx RP. Both panels can be valuable tools for clinicians, since they both display high sensitivity and specificity. We report a slightly better performance for BioFire RP2plus, since it produced no invalid results.


  • Open Access

    Convalescent Plasma Treatment of Patients Previously Treated with B-Cell-Depleting Monoclonal Antibodies Suffering COVID-19 Is Associated with Reduced Re-Admission Rates

    by Petros Ioannou, Athanasios Katsigiannis, Ioanna Papakitsou, Ioannis Kopidakis, Eirini Makraki, Dimitris Milonas, Theodosios D. Filippatos, George Sourvinos, Marina Papadogiannaki, Evaggelia Lydaki, et al.

    Patients receiving treatment with B-cell-depleting monoclonal antibodies, such as anti-CD20 monoclonal antibodies, such as rituximab and obinutuzumab, either for hematological disease or another diagnosis, such as a rheumatological disease, are at an increased risk for medical complications and mortality from COVID-19. Since inconsistencies persist regarding the use of convalescent plasma (CP), especially in the vulnerable patient population that has received previous treatment with B-cell-depleting monoclonal antibodies, further studies should be performed in thisdirection. The aim of the present study was to describe the characteristics of patients with previous use of B-cell-depleting monoclonal antibodies and describe the potential beneficial effects of CP use in terms of mortality, ICU admission and disease relapse. In this retrospective cohort study, 39 patients with previous use of B-cell-depleting monoclonal antibodies hospitalized in the COVID-19 department of a tertiary hospital in Greece were recorded and evaluated. The mean age was 66.3 years and 51.3% were male. Regarding treatment for COVID-19, remdesivir was used in 89.7%, corticosteroids in 94.9% and CP in 53.8%. In-hospital mortality was 15.4%. Patients who died were more likely to need ICU admission and also had a trend towards a longer hospital stay, even though the last did not reach statistical significance. Patients treated with CP had a lower re-admission rate for COVID-19 after discharge. Further studies should be performed to identify the role of CP in patients with treatment with B-cell-depleting monoclonal antibodies suffering from COVID-19.


  • Open Access

    Merkel Cell Polyomavirus (MCPyV) and Cancers: Emergency Bell or False Alarm?

    by Maria Georgia Dimitraki, George Sourvinos

    Merkel cell polyomavirus (MCPyV), the sole member of Polyomavirus associated with oncogenesis in humans, is the major causative factor of Merkel cell carcinoma (MCC), a rare, neuroendocrine neoplasia of the skin. Many aspects of MCPyV biology and oncogenic mechanisms remain poorly understood. However, it has been established that oncogenic transformation is the outcome of the integration of the viral genome into the host DNA. The high prevalence of MCPyV in the population, along with the detection of the virus in various human tissue samples and the strong association of MCPyV with the emergence of MCC, have prompted researchers to further investigate the role of MCPyV in malignancies other than MCC. MCPyV DNA has been detected in several different non-MCC tumour tissues but with significantly lower prevalence, viral load and protein expression. Moreover, the two hallmarks of MCPyV MCC have rarely been investigated and the studies have produced generally inconsistent results. Therefore, the outcomes of the studies are inadequate and unable to clearly demonstrate a direct correlation between cellular transformation and MCPyV. This review aims to present a comprehensive recapitulation of the available literature regarding the association of MCPyV with oncogenesis (MCC and non-MCC tumours).


  • Top Cited Papers
    Open Access

    From Traditional Ethnopharmacology to Modern Natural Drug Discovery: A Methodology Discussion and Specific Examples

    by Stergios Pirintsos, Athanasios Panagiotopoulos, Michalis Bariotakis, Vangelis Daskalakis, Christos Lionis, George Sourvinos, Ioannis Karakasiliotis, Marilena Kampa, Elias Castanas

    Ethnopharmacology, through the description of the beneficial effects of plants, has provided an early framework for the therapeutic use of natural compounds. Natural products, either in their native form or after crude extraction of their active ingredients, have long been used by different populations and explored as invaluable sources for drug design. The transition from traditional ethnopharmacology to drug discovery has followed a straightforward path, assisted by the evolution of isolation and characterization methods, the increase in computational power, and the development of specific chemoinformatic methods. The deriving extensive exploitation of the natural product chemical space has led to the discovery of novel compounds with pharmaceutical properties, although this was not followed by an analogous increase in novel drugs. In this work, we discuss the evolution of ideas and methods, from traditional ethnopharmacology to in silico drug discovery, applied to natural products. We point out that, in the past, the starting point was the plant itself, identified by sustained ethnopharmacological research, with the active compound deriving after extensive analysis and testing. In contrast, in recent years, the active substance has been pinpointed by computational methods (in silico docking and molecular dynamics, network pharmacology), followed by the identification of the plant(s) containing the active ingredient, identified by existing or putative ethnopharmacological information. We further stress the potential pitfalls of recent in silico methods and discuss the absolute need for in vitro and in vivo validation as an absolute requirement. Finally, we present our contribution to natural products’ drug discovery by discussing specific examples, applying the whole continuum of this rapidly evolving field. In detail, we report the isolation of novel antiviral compounds, based on natural products active against influenza and SARS-CoV-2 and novel substances active on a specific GPCR, OXER1.