The Coronavirus Took Advantage of Our Weaknesses

A physician explains the nature of opportunistic infection

Austin Perlmutter, MD
5 min readOct 22, 2020


Photo: Andriy Onufriyenko/Getty Images

In 1971, a professor of epidemiology named Abdel Omran proposed the epidemiological transition theory. He concluded there have been three main “stages” of human health concerns. First, in the pre-modern era, we dealt with widespread pestilence and famine. This time period was characterized by a high mortality rate and a low average life expectancy — around 20 to 40 years. Major causes of death included infections, malnutrition, and complications of childbirth.

Next came stage 2, dubbed “the age of receding pandemics.” Average life expectancy increased, averaging between 30 and 50 years. Infections remained a significant issue, but epidemic peaks became less frequent. Finally, early in the 20th century, we reached stage 3. Omran called this “the age of degenerative and man-made diseases,” when chronic conditions like heart disease and diabetes became our principal problems.

Scholars have debated the specifics of Omran’s theory, but the basic premise is sound: The burden of illness in humans has largely moved away from infectious concerns and towards chronic, often preventable diseases. Worldwide, high blood pressure, smoking, high blood sugar, and obesity are four of the top five risk factors for death. Of course, this doesn’t mean that infectious diseases have completely gone away. HIV/AIDS remains a major health threat, especially in Sub-Saharan Africa. Hundreds of thousands of people also die of malaria each year. Still, in industrialized nations, the overall threat from pathogens like bacteria, parasites, and viruses is now relatively low.

This pattern has been turned on its head in 2020.

As we’ve all learned in frightening, real time this year, the 2019 coronavirus strain (SARS-CoV-2 virus) rapidly spread from Wuhan, China to wrap its way around the world. Globalization fueled a steady viral march across countries and continents. By mid 2020, millions of people had been infected with the pathogen — a significant problem, as the SARS-CoV-2 virus can of course cause a potentially lethal disease: Covid-19. Unlike pandemics in times past, the interconnectivity of the modern world allowed for transmission of the pathogen across massive distances in a short amount of time.

As the pandemic rages on, scientific data has emerged indicating the virus does not affect everyone equally. Some people, especially those with pre-existing medical issues, are several times more likely to suffer severe complications from Covid-19, including death. Even early on in the spread of infection, we saw that conditions like high blood pressure, high blood sugar, obesity, and even smoking were associated with an increased risk for serious complications and death from the virus. These risk factors, of course, mirror the list of top contributors to death worldwide. As a broader understanding of Covid-19 evolved, people with preexisting conditions were told to take extra care in avoiding possible exposure. In our haste to protect people, we may have missed the most valuable takeaway from this growing pattern.

In medicine, certain infections are considered “opportunistic.” The causal pathogens in these cases are thought to take advantage of people with weakened immune systems. It’s a simple concept: These bugs don’t cause problems in healthy people, but can wreak havoc on someone with immune dysfunction. What if we looked at Covid-19 from this perspective? Could the increased risk conferred by chronic health conditions like high blood sugar represent an underlying immune dysfunction? What if Covid-19 was conceptualized as an opportunistic infection?

Long before 2020, scientific research had progressively shed light on a rather stunning discovery: immune dysfunction was at the core of many non-infectious diseases. Scientists have demonstrated that everything from heart disease to cancer can be understood through mechanisms of faulty immunity. It’s then unsurprising to note that high blood sugar, high blood pressure, and obesity are also linked to immune system malfunction. The most common chronic diseases of the modern world may in fact represent states of faulty immunity, and this may help explain much of the suffering around Covid-19. If millions of people with preexisting conditions already had immune dysfunction, was the stage alarmingly set for a health catastrophe long before the coronavirus arrived?

In medicine, certain infections are considered “opportunistic.” The causal pathogens in these cases are thought to take advantage of people with weakened immune systems.

There’s another troubling part of this story. Many chronic, preventable diseases seem to preferentially affect racial and ethnic minority groups. This mirrors trends in those negatively affected by the pandemic. There are several potential reasons for this. For example, people living at, below, or dangerously close to the poverty line (who are quite often minorities) may have decreased access to healthy food and increased exposure to psychological stress, each of which may negatively impact immune function. Other research finds that discrimination itself worsens health, increasing activation of the stress system and predisposing people to conditions like heart disease, obesity, and high blood pressure. This hard hitting combination creates an added layer of vulnerability to negative outcomes from the virus.

When taken together, the aforementioned concepts prompt critical questions. Are we missing the mark in our approach to Covid-19? Of course we need to do all that we can to decrease death rates and complications, but why are we so vulnerable to this virus to begin with? Imagine the SARS-CoV-2 virus as a storm that’s destroying our homes. One could argue that we’re blaming the storm for our problems, and doing our best to move people out of harm’s way while putting plywood over our windows. Maybe we also need to question why our homes are so flimsy to begin with — or why they were built so close to the water. And most importantly, we need to ask what happens — and then take the necessary steps to prepare for — when the next storm hits.

The SARS-CoV-2 virus has caused immeasurable grief and destruction around the world. But it’s imperative that we don’t regard the results of this pandemic as unavoidable or a one-off. While the virus showed us that we were logistically unprepared to handle an event of this magnitude, it also revealed an equally significant vulnerability. Our chronic health conditions have created a foundation of unhealthy immunity. They represent a major susceptibility to infections, and Covid-19 has proven itself capable of exploiting this weakness.

The current pandemic should force us to look at the real impact of chronic disease and the significance of preventive strategies. It represents the true toll of a system that facilitates a vicious cycle of poor health. This alarming data should reinforce the importance of behavior change, lifestyle modification, and effective means of adequately supporting both as essential components of medical care. When considering Omran’s theories through the lens of Covid-19, we can see that the difference between infections and chronic diseases may not be as significant as we once believed. Instead, our risk for severe complications from an infection may be more about our underlying immunity than the pathogen itself.



Austin Perlmutter, MD

Dr. Austin Perlmutter, co-author of BRAIN WASH, is a board-certified internal medicine physician.