COVID-19 Academic Resources Center
 

MDPI Comment on the COVID-19 Virus

Since 1996, MDPI has been committed to supporting the research community by providing the latest research freely available and making relevant and useful research available as quickly as possible. The world is current experiencing a pandemic of COVID-19, and researchers are working extremely hard to understand it and find a cure.

The values MDPI holds strongly are particularly important at the moment, and we will continue to publish relevant, peer-reviewed research as quickly as possible in open access format. This means that it will immediately be available for researchers, health professionals, and the general public to read, distribute, and reuse. We believe that scientific advancements will be crucial to overcoming this pandemic, and will do everything we can to support researchers working looking for solutions.

This page contains a variety of information related to COVID-19 available from MDPI, including journal articles, special issues, and preprints, among others.

Recent Publications

25 pages, 737 KB  
Article
From Triplex to Quadruplex: Enhancing CDC’s Respiratory qPCR Assay with RSV Detection on Panther Fusion® Open Access™
by Andy Caballero Méndez, Mayeline N. Sosa Ortiz, Roberto A. Reynoso de la Rosa, Miguel E. Abreu Bencosme and Karla V. Montero Lebrón
Microorganisms 2026, 14(1), 167; https://doi.org/10.3390/microorganisms14010167 - 12 Jan 2026
Abstract
The overlapping circulation of influenza (Flu), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; SC2), and respiratory syncytial virus (RSV) continues to challenge clinical laboratories, particularly in settings with limited automation and fragmented healthcare coverage. This study expanded the CDC Flu-SC2 assay by incorporating [...] Read more.
The overlapping circulation of influenza (Flu), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; SC2), and respiratory syncytial virus (RSV) continues to challenge clinical laboratories, particularly in settings with limited automation and fragmented healthcare coverage. This study expanded the CDC Flu-SC2 assay by incorporating a laboratory-developed test (LDT) for RSV A/B detection into a fully automated quadruplex RT-qPCR (LDRA) on the Panther Fusion® Open Access™ system. The design, based on more than 8000 RSV genomic sequences targeting the conserved M gene, achieved optimal amplification efficiencies (97–105%) and full multiplex compatibility. Analytical assessment established limits of detection between 9.6 and 37.8 copies per reaction, absence of cross-reactivity with 30 respiratory pathogens, and inclusivity for 32 viral variants. Commutability and diagnostic performance among the LDRA, CE IVD-marked Allplex™ SARS-CoV-2/FluA/FluB/RSV, and US IVD-marked Panther Fusion® SARS-CoV-2/Flu A/B/RSV Assays were evaluated using 405 nasopharyngeal UTM-preserved swabs. The LDRA demonstrated excellent concordance (overall agreement ≥ 98%, κ > 0.95), strong diagnostic accuracy, and reliable detection of mixed infections. This quadruplex provides a fully automated, rapid, and accurate solution for the simultaneous detection of influenza A, influenza B, SARS-CoV-2, and RSV viruses, enhancing molecular diagnostic capacity and supporting equitable, timely clinical decision-making in middle-income healthcare systems such as that of the Dominican Republic. Full article
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37 pages, 801 KB  
Systematic Review
A Systematic Review of Urban Heat Island (UHI) Impacts and Mitigation: Health, Equity, and Policy
by Zhenzhu Zheng, Chng Saun Fong, Nasrin Aghamohammadi and Yoo Kee Law
Systems 2026, 14(1), 82; https://doi.org/10.3390/systems14010082 - 12 Jan 2026
Abstract
Urban heat islands pose intensifying threats to public health, equity, and urban livability as climate change amplifies temperature extremes. This systematic review synthesizes evidence from 33 primary studies (2021–2025) examining health impacts, mitigation strategies, and policy integration. The analysis focuses on interaction mechanisms, [...] Read more.
Urban heat islands pose intensifying threats to public health, equity, and urban livability as climate change amplifies temperature extremes. This systematic review synthesizes evidence from 33 primary studies (2021–2025) examining health impacts, mitigation strategies, and policy integration. The analysis focuses on interaction mechanisms, specifically how mitigation strategies differentially reduce health burdens across vulnerable populations, to advance systems-level understanding of urban heat dynamics. Following PRISMA guidelines, the review examined these mechanisms across three interconnected domains: health burdens, physical mitigation effectiveness, and post-pandemic policy synergies. Findings reveal profound inequities in heat exposure and associated health outcomes, with disadvantaged populations experiencing 26–45% higher heat-related mortality risk and 3–4 °C greater exposure than affluent communities, even after controlling for income. Physical mitigation strategies show measurable effectiveness, providing 1–6 °C cooling from green infrastructure and 2–22 °C from cool surfaces. Optimal interventions vary by socioeconomic context, with urban trees being more effective in disadvantaged areas, while cool roofs are better suited to affluent zones. COVID-19 natural experiments demonstrated 30–50% anthropogenic heat reductions, revealing strategic opportunities for integrating heat mitigation with 15-Minute City planning and work-from-home normalization. Effective implementation requires moving beyond isolated interventions toward spatially differentiated, equity-centered strategies aligned across planning, transportation, and governance domains. The post-pandemic period presents a critical window for embedding heat mitigation into broader urban transformation agendas. Full article
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16 pages, 573 KB  
Article
The Timing of Intrauterine Exposure to Maternal SARS-CoV-2 Infection Impacts Neurodevelopment and Growth Trajectories During the First Year of Life
by Thomas N. Griffin, Andrés M. Treviño-Alvarez, Tomás Cabeza de Baca, Paolo Piaggi, Asmaa Yehia, Beatriz E. Chávez-Luévanos and Osama A. Abulseoud
J. Clin. Med. 2026, 15(2), 600; https://doi.org/10.3390/jcm15020600 - 12 Jan 2026
Abstract
Background: The effect of intrauterine exposure to SARS-CoV-2 infection during pregnancy on neurodevelopment and growth trajectories during the first year of life remains under investigation. Methods: We retrospectively reviewed the electronic medical records of all pregnant women who received care at Mayo Health [...] Read more.
Background: The effect of intrauterine exposure to SARS-CoV-2 infection during pregnancy on neurodevelopment and growth trajectories during the first year of life remains under investigation. Methods: We retrospectively reviewed the electronic medical records of all pregnant women who received care at Mayo Health System and tested positive for SARS-CoV-2 (RT-PCR) from March 2020 through October 2021 and examined the effects of fetal sex and trimester of maternal SARS-CoV-2 infection on the risk of neurodevelopmental disorder diagnosis and growth trajectories of head circumference (HC) and body weight (BW) percentiles over the first year of life using linear mixed models. Results: We observed that a higher percentage of male infants (n = 357), compared to females (n = 344), have neurodevelopmental disorders (10.9% vs. 5.2%, p = 0.008), and infants exposed to maternal SARS-CoV-2 infection in the second (n = 183) or third trimester (n = 358) have a higher prevalence of neurological diagnoses compared to those exposed in the first trimester (n = 160) (1st vs. 2nd vs. 3rd trimester: 0% vs. 0.9% vs. 0.7%, respectively, p = 0.037). In addition, female infants, compared to males, had significantly lower BW (B = −0.04, p < 0.0001) and HC (B = −0.06, p < 0.0001) percentile growth trajectories over the first year of life. Moreover, infants exposed to maternal SARS-CoV-2 infection in the second trimester had a significantly lower BW percentile growth trajectory (B = −0.01, p = 0.006), while infants exposed to maternal SARS-CoV-2 infection in the third trimester had a significantly lower HC percentile growth trajectory (B = −0.02, p = 0.02). Conclusions: In utero exposure to maternal SARS-CoV-2 infection could have long-term effects on growth trajectories, depending on the infant’s sex and timing of exposure. Full article
(This article belongs to the Section Clinical Pediatrics)
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17 pages, 665 KB  
Article
Respiratory and Pleural Pathogens in Octogenarians Hospitalized with COVID-19: Impact of Secondary Bacterial Pneumonia on Day-5 SOFA and Mortality
by Petrinela Daliu, Felix Bratosin, Ovidiu Rosca, Monica Licker, Elena Hogea, Livia Stanga, Camelia Vidita Gurban and Delia Muntean
Microorganisms 2026, 14(1), 164; https://doi.org/10.3390/microorganisms14010164 - 12 Jan 2026
Abstract
Background and Objectives: Secondary bacterial infection drives poor outcomes in older adults with COVID-19, but age-specific microbiology and its interaction with severity scores are not well defined. We characterized respiratory and pleural pathogens, resistance profiles, and their impact on day-5 SOFA/APACHE II in [...] Read more.
Background and Objectives: Secondary bacterial infection drives poor outcomes in older adults with COVID-19, but age-specific microbiology and its interaction with severity scores are not well defined. We characterized respiratory and pleural pathogens, resistance profiles, and their impact on day-5 SOFA/APACHE II in octogenarians versus younger adults. Methods: We performed a retrospective cohort study of adults with RT-PCR-confirmed coronavirus disease 2019 (COVID-19) at a tertiary infectious diseases center (≥80 years, n = 152; <65 years, n = 327). Respiratory and pleural samples were processed according to EUCAST standards. Identification employed matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Pathogen distributions, susceptibilities, and rates of superimposed pneumonia, empyema, and bacteremia were compared by age, and associations between secondary pneumonia, day-5 SOFA/APACHE II, and 28-day mortality were analyzed. Results: Sputum was obtained in 67.1% of older and 65.7% of younger adults, with numerically higher culture positivity in older patients (73.5% vs. 65.1%). Pathogen spectra were similar, dominated by Streptococcus pneumoniae (24.0% vs. 24.3%), methicillin-susceptible Staphylococcus aureus (MSSA) (18.7% vs. 20.7%), methicillin-resistant Staphylococcus aureus (MRSA) (9.3% vs. 6.4%), and Klebsiella pneumoniae, including extended-spectrum β-lactamase (ESBL)-producing strains. Empyema was more frequent in octogenarians (7.9% vs. 3.1%), and pleural cultures were usually positive. Meropenem retained 100% activity against ESBL-producing K. pneumoniae and Pseudomonas in both strata. In ≥80-year-olds, superimposed pneumonia was associated with higher day-5 SOFA (6.6 vs. 5.5) and APACHE II (24.3 vs. 21.0) scores and markedly increased 28-day mortality (37.5% vs. 9.8%). Conclusions: In octogenarians with COVID-19, secondary bacterial pneumonia and empyema are frequent, microbiologically similar to younger adults, and strongly amplify organ dysfunction and mortality even with largely preserved carbapenem susceptibility. Full article
(This article belongs to the Section Medical Microbiology)
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25 pages, 6043 KB  
Article
Identifying Key Metabolites in South African Medicinal Plants Using Dual Electrospray Ionization Metabolomics
by Mmamudi Anna Makhafola, Clarissa Marcelle Naidoo, Chikwelu Lawrence Obi, Benson Chuks Iweriedor, Oyinlola Oluwunmi Olaokun, Earl Prinsloo, Muhammad Sulaiman Zubair and Nqobile Monate Mkolo
Plants 2026, 15(2), 232; https://doi.org/10.3390/plants15020232 - 12 Jan 2026
Abstract
Despite growing interest in South African medicinal plants, advanced metabolomic workflows that integrate positive (ESI+) and negative (ESI−) ionization modes in UPLC-MS/MS remain sparsely applied to South African flora, and especially to Acorus calamus and Lippia javanica species. Herein, application of a dual-polarity [...] Read more.
Despite growing interest in South African medicinal plants, advanced metabolomic workflows that integrate positive (ESI+) and negative (ESI−) ionization modes in UPLC-MS/MS remain sparsely applied to South African flora, and especially to Acorus calamus and Lippia javanica species. Herein, application of a dual-polarity (positive (ESI+) and negative (ESI−) ionization modes) using an untargeted UPLC–MS/MS workflow, integrated with HEK293T cytotoxicity screening, to map their metabolomes, and rank potential signature metabolites for targeted antiviral follow-up. SwissADME supported in silico drug-likeness. Neither plant extract was cytotoxic across the concentration range, with absorbance-based cell viability of 73.82% for L. javanica and 77.23% for A. calamus at 250 µg/mL, and fluorescence-based cell viability ≥59.87% and ≥55.89%, respectively. Dual-polarity expanded coverage with ESI− yielded 312 features, compared with 225 with ESI+, consistent with the predominance of acidic phenolics in plant species. Unsupervised and supervised models segregated the plant species (PCA PC1/PC2 variance: ESI+ 89.4%/3.0%; ESI− 93.5%/1.8%; R2X(cum) = 0.799). Differential analysis identified 118 significant features in ESI+ with 80 up-regulated, 38 down-regulated, and 139 in ESI− with 96 up-regulated, 43 down-regulated. The ESI− showed the wider dynamic range. Chemotypes enriched among significant metabolites include flavonols of 3-O-methylkaempferol, apigenin, and conjugates of Pollenin A, iridoid glycosides of oleoside, forsythoside B, and jasmonate-pathway oxylipins of 7-epi-12-hydroxyjasmonic acid and its glucoside. These also include caryoptosidic acid and catechin-7-glucoside, which are ionized in both modes, pinning the increase in biomarker robustness. In conclusion, a dual-mode UPLC–MS/MS approach, integrated with cytotoxicity exploration, delivers a complementary metabolome coverage and a safety awareness for shortlisting of potential signature metabolites from L. javanica and A. calamus. Moreover, in vitro inhibition of SARS-CoV-2 papain-like protease (PLpro) by these plants links chemical signatures to antiviral relevance. Shortlisted significant metabolites that demonstrated favorable drug-likeness include flavonol scaffolds of 3-O-methylkaempferol, Pollenin A, and jasmonate-pathway derivatives of 7-epi-12-hydroxyjasmonic acid. Moreover, the dual ionization mode may eliminate ionization bias, broaden metabolome coverage, and yield a mechanism-ready shortlist of metabolites from South African medicinal plants for downstream antiviral investigation. Full article
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18 pages, 4818 KB  
Article
Temporal Trends in Lower Respiratory Infection Mortality in Ecuador, 2012–2022
by Reena Krishna, Luis Furuya-Kanamori and Harriet L. S. Lawford
Trop. Med. Infect. Dis. 2026, 11(1), 21; https://doi.org/10.3390/tropicalmed11010021 - 12 Jan 2026
Abstract
Lower respiratory infections (LRIs) are responsible for significant morbidity and mortality in Ecuador; however, evidence to support prevention strategies is limited. This study aimed to identify age-specific trends, spatial patterns, and sociodemographic risk factors of LRI mortality in Ecuador between 2012–2022, utilizing national [...] Read more.
Lower respiratory infections (LRIs) are responsible for significant morbidity and mortality in Ecuador; however, evidence to support prevention strategies is limited. This study aimed to identify age-specific trends, spatial patterns, and sociodemographic risk factors of LRI mortality in Ecuador between 2012–2022, utilizing national mortality data sourced from the Ecuadorian National Institute for Statistics and Censuses (INEC). Age-sex-specific trend analysis was performed using Joinpoint regression. LRI age-standardized mortality rates (ASMRs) were mapped by province of death, and percentage change was calculated between 2012 and 2019. Multivariable logistic regression was performed to assess risk factors pre- and post-2020. A change in trend in LRI mortality rate, from a decreasing trend to a marginal increasing trend, was identified for both genders in children aged 0–4 and 5–15 years. There were significant increasing trends for males (2014–2019 APC: 2.21%, 95% CI: 0.57, 6.70) and females (2016–2019 APC: 4.62%, 95% CI: 0.84, 10.58) aged ≥ 70 years. From 2012 to 2019, the highest average LRI ASMR was in Guayas (30.90 deaths per 100,000 inhabitants), and the greatest percentage increase was observed in Orellana (419.54%). Before 2020, LRI mortality, compared to deaths of other causes, was significantly associated with sex, age, education, ethnicity, place of death and climate region, with major shifts post COVID-19 pandemic. Full article
(This article belongs to the Special Issue Respiratory Infectious Disease Epidemiology and Control)
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Sequencing Techniques and Genomics Technologies to Help with Diagnostics and Virus Characterization – Focus on COVID 19
edited by , Hugh E. Olsen, and
submission deadline 15 Apr 2021 | 10 articles | Viewed by 71581
Keywords: Genomics technologies; Sequencing techniques; Metagenomics; Virus sequencing; Genetic diagnostics; qPCR; Nanopore sequencing; Single-molecule real-time (SMRT) sequencing; Next-generation sequencing (NGS); Third-generation sequencing; Virus characterization; Long-read sequencing; Comparative genomics; Functional genomics; Diagnostic tests; Infectious diseases; Pandemic; SARS-CoV-2; COVID-19; Coronavirus; Genomic epidemiology; Population stratification; Genetic susceptibility; Host interactions
(This special issue belongs to the Section Technologies and Resources for Genetics)
Advances in SARS-CoV-2 Variants and Vaccines
edited by Scott Roberts
submission deadline 20 Jan 2026 | Viewed by 263 | Submission Open
Keywords: SARS-CoV-2; COVID-19; vaccine; epidemiology; public health; preparedness
(This special issue belongs to the Section Infectious Diseases)
Recent Advances in Pathophysiology and Immunology Related to SARS-CoV-2 Infection
edited by
submission deadline 20 Jan 2026 | 9 articles | Viewed by 16246 | Submission Open
Keywords: SARS-CoV-2; COVID-19; immunology; pathophysiology; immunopathology
(This special issue belongs to the Section Molecular Pathology, Diagnostics, and Therapeutics)
Rehabilitation and Treatment of Post-COVID-19 Condition submission deadline 20 Jan 2026 | 1 articles | Viewed by 918 | Submission Open
Keywords: post-COVID-19 condition; myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS); comorbidities; interdisciplinary; multimodal; digital medicine; rehabilitation; treatment; health-related quality of life; disability; return to work
(This special issue belongs to the Section Clinical Rehabilitation)
TMPRSS2 and Other Host Factors in Influenza Virus and Coronavirus Infections
edited by and Sze Keong Tey
submission deadline 31 Jan 2026 | 2 articles | Viewed by 6789 | Submission Open
Keywords: TMPRSS2; host factors; influenza virus; coronavirus; viral infection; treatment of viral diseases
(This special issue belongs to the Section Human Virology and Viral Diseases)
How COVID-19 Affects Cancer Patients
edited by
submission deadline 31 Jan 2026 | 15 articles | Viewed by 37375 | Submission Open
Keywords: COVID-19; pandemic; cancer; impact; incidence; mortality; lethality; disparities; gender
(This special issue belongs to the Section Cancer Epidemiology and Prevention)

State-of-the-Art Webinars on COVID-19


WEBINAR 1: How to Avoid a New Lockdown?

The first webinar in the series, held on 17 April 2020, saw both Prof. Dr. Antoine Flahault, Director of the Institute of Global Health, University of Geneva, Switzerland, and Prof. Dr. Evelyne Bischof, Associate Professor, Shanghai University of Medicine and Health Sciences, Shanghai, China and Research physician, University Hospital of Basel, Basel, Switzerland speak on this topic.

The recording can be found here.

WEBINAR 2: Coronaviruses: History, Replication, Innate Immune Antagonism

The second webinar in the series, entitled “Coronaviruses: history, replication, innate immune antagonism”, saw Prof. Dr. Susan R. Weiss, Professor of Microbiology, Perelman School of Medicine, University of Pennsylvania speak on this topic.

The recording can be found here.

WEBINAR 3: Could the COVID-19 Crisis be the Opportunity to Make Cities Carbon Neutral, Liveable and Healthy

The third webinar in this series was presented by Prof. Dr. Mark Nieuwenhuijsen, a world leading expert in environmental exposure assessment, epidemiology, and health risk/impact assessment with a strong focus and interest on healthy urban living. 

The recording can be found here

WEBINAR 4: COVID-19 - Global Supply Chains and the SDGs

For the fourth webinar of this series, Prof. Dr. Max Bergman, Dr. Dorothea Schostok and Prof. Dr. Patrick Paul Walsh gave a presentation on Global Supply Chains and the SDGs. 

The recording can be found here.

WEBINAR 5: The New Role of Family Physicians in Times of COVID-19

The fifth webinar of the COVID-19 Series saw Prof. Dr. Christos Lionis discuss the new role of family physicians that emerged during the COVID-19 pandemic.

The recording can be found here.

WEBINAR 6: Survey on Symptoms/Signs, Protective Measures, Level of Awareness and Perception Regarding COVID-19 Outbreak among Dentists

In the sixth webinar of this series, Prof. Dr. Guglielmo Campus and Prof. Dr. Maria Grazia present and discuss the risk and the preventions that can and should be taken by dentists during this pandemic.

The recording can be found here.

WEBINAR 7: Living with COVID-19: An Early Intervention Therapeutic Strategy to Control the Pandemic

The seventh webinar of the COVID-19 series, Dr. Hamid Merchant discussed the different therapeutic strategies that can be adopted in the early stages of the infection.

The recording can be found here.

WEBINAR 8: Impact of COVID-19 on Routine Immunization, Reproduction and Pregnancy Outcome

For the eighth COVID-19 webinar, Prof. Dr. Jon Øyvind Odland discussed the effect that COVID-19 seems to have on pregnant women; whereas Prof. Dr. Giovanni Gabutti discussed the role of routine immunization as a way of fighting COVID-19.

The recording can be found here.

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