The severity of  COVID-19 in comparison with seasonal influenza
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In a latest research below evaluate on the Archives of Virology journal and at the moment posted to the Research Square* preprint server, investigators in Israel assessed the disparities and similarities between seasonal influenza and extreme acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections.

Study: SARS-CoV-2 and Seasonal Influenza: Similarity and Disparity. Image Credit: Lightspring / Shutterstock


The coronavirus illness 2019 (COVID-19) combines radiological and scientific options with influenza virus-induced respiratory sickness. Unfortunately, it’s robust to find out the distinction between these two viruses simply by analyzing their scientific displays. 

Since the beginning of the SARS-CoV-2 pandemic, researchers have drawn parallels between influenza and COVID-19. The severity of COVID-19 relative to seasonal influenza continues to be a subject of debate. 

Further, an early distinction between SARS-CoV-2 an infection and influenza viruses is important amongst hospitalized sufferers. This is very essential for the time being as a result of healthcare establishments are dealing with seasonal influenza and the continuing COVID-19 pandemic. 

Moreover, the epidemiologic implications, the likelihood for airborne transmission, insufficient baseline herd immunity, and differing therapeutic strategies emphasize the significance of distinguishing between SARS-CoV-2- and influenza-infected sufferers.

About the research

In the current retrospective analysis, the scientists decided if there have been any variations in scientific presentation and illness severity between influenza and COVID-19 throughout hospitalized sufferers. The research was carried out at a 1000-bedded university-affiliated tertiary care hospital treating over two million folks in northern Israel, named Rambam Health Care Campus (RHCC). 

The investigation included all adults hospitalized in RHCC with confirmed-COVID-19 in the course of the second SARS-CoV-2 wave in Israel between 1 June 2020 and 31 August 2020. These sufferers have been in comparison with people admitted with influenza-induced respiratory sickness between 1 November 2019 and 31 August 2020. The outcomes and scientific options of the hospitalized COVID-19 and influenza sufferers have been in contrast.

Data together with scientific and demographic particulars, laboratory measures throughout admission, and the National Early Warning Score 2 (NEWS2), have been collected from the RHCC’s digital medical data. Further, the statistical bundle for social sciences (SPSS) model 26 software program was used to research the info.

Results and discussions

Collectively, the research outcomes depicted {that a} whole of 152 COVID-19 and 136 influenza sufferers have been included within the research. 

Runny nostril, cough, dyspnea, myalgia, and comorbidities have been extra frequent in influenza sufferers than in SARS-CoV-2 sufferers. Hypoxemia on admission, heightened liver enzymes, or smoking behavior was additionally extra prevalent in influenza sufferers. Overall, the people with influenza an infection demonstrated typical flu-like signs.

Patients with COVID-19, then again, have been chubby, had lymphopenia of lower than 1500, C reactive protein (CRP) of greater than 5 mg/dL, or radiographic anomalies. According to the mounting proof, persistent irritation, and extra adiposity related to weight problems enhances the vulnerability to viral infections and sickness severity due to immune system dysregulation and excessive proinflammatory cytokines ranges.

The most prevalent laboratory abnormality in COVID-19 sufferers was lymphopenia, which was 54 occasions extra frequent than in people contaminated with influenza. Direct lymphocytes viral an infection because of the presence of angiotensin-converting enzyme 2 (ACE2) receptors on their cell membrane and provoked lymphocyte deficit owing to proinflammatory cytokines have been two potentialities that justify the numerous lymphopenia in SARS-CoV-2 an infection.

COVID-19 sufferers had a better share of irregular chest x-rays (CXRs), primarily manifested as bilateral infiltrates. This inference was consistent with a number of earlier research. However, it was at odds with a previous smaller research. 

Besides, the incidence of dehydration at hospital admission was elevated in SARS-CoV-2 sufferers. The intravascular exhaustion brought on by the virus’s direct affect on renal ACE2 receptors may clarify this phenomenon.

The demand for ventilatory help, period of hospital keep, and 30-day mortality have been comparable in each teams, regardless of influenza sufferers experiencing a extreme sickness with a NEWS2 of greater than six on admission. Contrary to the current research, a previous investigation from Germany found that hospitalized COVID-19 sufferers had heightened in-hospital loss of life and poorer scientific outcomes, comparable to size of hospital keep and air flow, acute renal harm, and acute respiratory misery syndrome.


Study findings revealed that influenza sufferers have been extra critically in poor health throughout their keep within the hospital than sufferers with SARS-CoV-2. Both cohorts, nonetheless, had equal in-hospital loss of life and scientific outcomes. 

Furthermore, the 2 illnesses harbored distinct properties that allow them to be separated from each other in the course of the admission time until laboratory analysis. The various traits of COVID-19 and influenza facilitate the implementation of acceptable preventative methods and an infection management approaches from the purpose of hospital arrival.

*Important discover

Preprints with Research Square publish preliminary scientific studies that aren’t peer-reviewed and, subsequently, shouldn’t be considered conclusive, information scientific observe/health-related habits, or handled as established info.

Journal reference:

  • Halima Dabaja-Younis, Eyal Fuchs, Nadeem Shorbaji et al. SARS-CoV-2 and Seasonal Influenza: Similarity and Disparity, 10 June 2022, PREPRINT (Version 1) obtainable at Research Square, DOI:,

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