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Variability in the Infectiousness of COVID-19

By May 26, 2020Articles

By Sukhwinder Lakhman, PhD
Associate Professor, Department of Pharmaceutical Sciences

COVID-19 is, in many ways, proving to be a disease of uncertainty. According to a new study from Italy, some 43 percent of people with the virus have no symptoms. Among those who do develop symptoms, it is common to feel sick in an uncomfortable but familiar way. “There’s a big difference in how people handle this virus,” says Robert Murphy, a professor of medicine and the director of the Center for Global Communicable Diseases at Northwestern University. Also, It’s very unusual as well. None of this variability fits with any other diseases we’re used to dealing with in past.

This degree of uncertainty has less to do with the virus itself than how our bodies respond to it. when doctors see this sort of variation in disease severity, “that’s not the virus; that’s the host.” Since the beginning of the pandemic, people around the world have heard the message that older and chronically ill people are most likely to die from COVID-19. But that is far from a complete picture of who is at risk of life-threatening disease. Understanding exactly how and why some people get so sick while others feel almost nothing will be the key to treatment.

Once the virus has spread widely within our body, our immune system becomes the thing that more urgently threatens to kill us. That response cannot be fully controlled. But it can be modulated and improved. When the coronavirus attaches to cells, it hooks on and breaks through, then starts to reproduce. It does so especially well in the cells of the nasopharynx and down into the lungs but is also known to act on the cells of the liver, bowels, and heart. The virus spreads around the body for days or weeks in a sort of stealth mode, taking over host cells while evading the immune response. It can take a week or two for the body to fully recognize the extent to which it has been overwhelmed. At this point, its reaction is often not calm and measured. The immune system goes into a hyperreactive state, pulling all available alarms to mobilize the body’s defense mechanisms. This is when people suddenly crash. Some researchers believe such a balance is possible. Because cytokine storms are not unique to COVID-19. The same basic process happens in response to other viruses, such as dengue and Ebola, as well as influenza and other coronaviruses. It is life-threatening and difficult to treat, but not beyond the potential for mitigation.

At Johns Hopkins University, the biomedical engineer Joshua Vogelstein and his colleagues have been trying to identify patterns among people who have survived cytokine storms and people who haven’t. One correlation the team noticed was that people taking the drug tamsulosin (sold as Flomax, to treat urinary retention) seemed to farewell. Vogelstein is unsure why. Cytokine storms do trigger the release of hormones such as dopamine and adrenaline, which tamsulosin can partially block. The team is launching a clinical trial to see if the approach is of any help us give more insight for its treatment. One of the more promising approaches is blocking cytokines themselves—once they’ve already been released into the blood. A popular target is one type of cytokine known as interleukin-6 (IL-6), which is known to peak at the height of respiratory failure.

About American University of Health Sciences

AUHS is a Christian based, minority-serving university, which educates students for careers in the healthcare profession. AUHS emphasizes the values of faith in God, love of humankind, and belief that all people have a right to healthcare and deserve a good quality of life based on the wellness of body, mind, and spirit. The university celebrates diversity and reaches out to groups currently underrepresented in healthcare and research. AUHS provides the undergraduate and graduate curriculum, hands-on practical training and supportive environment required to create competent and compassionate healthcare professionals.

American University of Health Sciences is accredited by the WASC Senior College and University Commission (WSCUC), 985 Atlantic Avenue, Suite 100, Alameda, CA 94501, 510.748.9001. WSCUC is a regional accrediting body recognized by the U.S Department of Education (USDOE) and the Council on Higher Education Accreditation (CHEA). wascsenior.org

American University of Health Sciences (AUHS) is a member of the Transnational Association of Christian Colleges and Schools (TRACS) [15935 Forest Road, Forest VA 24551; Telephone: (434) 525-9539; e-mail: info@tracs.org], having been awarded Accredited Status as a Category III institution by the TRACS Accreditation Commission on October 24, 2017. This status is effective for a period of up to five years. TRACS is recognized by the United States Department of Education (USDOE), the Council for Higher Education Accreditation (CHEA), and the International Network for Quality Assurance Agencies in Higher Education (INQAAHE). tracs.org