What Science and History Can Tell Us About COVID-19

The internet is a wonderful tool, when wielded correctly. But when people follow it blindly they can be misled or come to believe things that are simply not true. Here are some science and history facts you may want to know about before reading any more opinions about COVID-19 on social media.

Science Evolves

In 1847, Ignaz Semmelweis noticed a peculiar thing. One of the two birthing clinics he was in charge of had a much higher mortality rate for the mothers than the other clinic. The pregnant women of the city had clearly already noticed this trend. They would beg to be admitted to the clinic that had the lower mortality rate, and if denied they would prefer to deliver their children in the street rather than go to the other clinic.

Semmelweis compared everything about the two clinics—the climate, the crowding, the techniques used—but could find nothing that could account for the difference in the mortality rates. That is until his friend, who was nicked by a scalpel while teaching how to perform an autopsy, died with similar symptoms to the women in the less successful second clinic.

From this, Semmelweis was able to produce a theory. The clinic with the lower mortality rate was run by midwives who were not exposed to corpses during the course of their day. The clinic with the higher mortality rate was run by doctors as part of a teaching hospital in which doctors and students performed autopsies in addition to deliveries. Semmelweis concluded that cross contamination from the corpses was causing the illness and deaths of the women. He ordered those working in his teaching hospital clinic to wash their hands with a chlorinated solution before assisting a childbirth, and managed to reduce the mortality rate at his doctor-run clinic by 90 percent.

Semmelweis went on to present his findings to fellow doctors at other hospitals and clinics around the world. But, instead of being met with joy and relief that the issue could be easily corrected, he was dismissed and even mocked by other doctors, and was eventually committed to an insane asylum. Ironically, it is believed that while confined he died from septic shock due to an unclean wound.

I can’t help but think of Semmelweis every time someone says that we shouldn’t have to wear masks to protect against transmission of COVID-19, arguing that the CDC initially said that we didn’t need them, so why should we start now? I imagine Semmelweis holding his data showing that washing hands reduced the mortality rate in his clinic from 18.27 percent to 1.27 percent, while other doctors insisted that they had never washed their hands before, so why should they start now?

The answer, of course, is as simple now as it was then: science adapts and evolves as new information is learned. This was true when Schrödinger updated Bohr’s model of the atom, when Darwin put forth the theory of natural selection, when Pluto was reclassified from planet to dwarf planet, when hydrothermal vents in the deep ocean were found to support life without sunlight, and when feathers were added to dinosaur models. Changing a theory as new information is learned is what has allowed us to move from bloodletting to modern medicine.

Oxygen and Carbon Dioxide Are Smaller than COVID-19

There are many false statements online claiming that masks trap toxic levels of carbon dioxide from exhaled breath and prevent oxygen from being taken in, all while not stopping the virus. But, this can be easily dismissed using basic math.

For starters, COVID-19 particles are 60 to 140 nm, while oxygen molecules are about 0.299 nm. That makes COVID-19 particles at least 200 times larger than oxygen molecules. Simply put, this is greater than the size difference between a school bus and a die-cast toy school bus. To say that a mask is useless because it blocks oxygen while simultaneously claiming it allows COVID-19 to pass through is like saying the spaces in a chain-link fence stop toy vehicles but allow actual vehicles to pass through. Which you have to admit would be a pretty neat trick.

 

The same is true for carbon dioxide molecules versus COVID-19. Although carbon dioxide is a little bigger than oxygen at about 0.33 nm, it is still much, much smaller than COVID-19. It is physically impossible that a barrier could both prevent the tiny carbon dioxide molecules from escaping while also allowing COVID-19 to flow through unimpeded. As the saying goes, you cannot have your cake and eat it too.

Further, research indicates that airborne transmission occurs when COVID-19 particles travel suspended in droplets of respired liquid. This means that the masks don’t need pores that are smaller than the size of individual COVID-19 particles, masks need pores that are smaller than the size of the larger, breathed-out droplets that the COVID-19 particles are inside. Numerous studies have shown that cotton does help prevent the passage of droplets , due in part to the complex web of fibers that natural cotton can form.

While the temptation may be to use N95 masks at all times instead of cotton, N95 masks should be professionally fitted to be effective. These masks therefore should be reserved for our healthcare professionals and their most vulnerable patients who need them because of the frequency of their exposure to both those with COVID-19 and those with compromised immune systems. However, two layers of cotton have been found to be able to block up to 94 percent of large, high-velocity droplets (like those from coughing or sneezing), so homemade cotton masks are a good, affordable alternative to N95s.

You Can Spread Disease Even When You Feel Fine

Mary Mallon felt fine too. She insisted that it was impossible that she was making her employers ill because she had no symptoms. Yet despite how she felt, “Typhoid Mary” Mallon is believed to have infected an astounding 122 people with typhoid from 1900 to 1907, five of whom died. Why is this astounding, you may ask, 122 sick and five dead doesn’t seem like very many. True, and yet here we are over 100 years later, still using the term “Typhoid Mary” to describe a carrier of disease. It isn’t hard to imagine that Mary would be astonished to know her name has lived on in infamy for over a century because she refused to admit she could be spreading typhoid while feeling fine.

The fact is, many diseases can be spread while the carrier “feels fine.” This can be due to one of two things: the person can be asymptomatic (has the disease but has no symptoms, like Typhoid Mary), or presymptomatic (has the disease but hasn’t shown symptoms yet, like when you first catch a cold).

With most illnesses, the infected person doesn’t show symptoms immediately. For example, if someone with the flu sneezes near you and you become infected, you don’t immediately have a fever of 102°F. Illnesses take time to show themselves, and during that period of incubation an infected person can be contagious even though they haven’t started showing symptoms yet. COVID-19 is no different—someone may have the disease today and feel fine, and not start to feel ill until tomorrow or later in the week.

While researchers are still trying to work out whether asymptomatic people can spread COVID-19, research shows that presymptomatic people can, and that’s why it’s important to wear a mask in public even when you’re feeling fine. Mask wearing is a small inconvenience that can help us all avoid potentially infecting others before we even know we are ill.

About Half of Americans Have a Preexisting Condition

Many people online have argued that only the elderly and people with preexisting conditions are hospitalized or die from COVID-19. Overlooking that this statement is simply not true, one has to admit it’s pretty callous. Especially when you consider that preexisting conditions include not only old age, but also diabetes, obesity, asthma, cardiovascular disease, being a smoker, and even being pregnant.

And, much like Typhoid Mary, believing that you and your loved ones don’t have a preexisting condition doesn’t make it true. In 2020 America, 42 percent of the population is obese —that’s more than the percentage of Americans with bachelor’s degrees (33.4 percent). Additionally, about 8.5 percent of children and 8 percent of adults have asthma, 10 percent of adults have diabetes, and about 15 percent of Americans are smokers. Last but not least, nearly half of adult Americans are believed to have some form of cardiovascular disease.

So, if you look to the person to your left and the person to your right, odds are one of the three of you has a preexisting condition that isn’t old age, whether you know it or not.

What Doesn’t Kill You Does Not Make You Stronger

Ever heard someone say “my old football injury is acting up”? The truth is, while the body may heal after trauma, it frequently doesn’t go back to 100 percent of its previous condition. Not everything that causes long-term or permanent damage to the body kills you. Broken bones ache with the weather, once-injured joints develop arthritis, the Nipah virus can reactivate years after an initial recovery, and the virus that causes chickenpox in childhood can stay dormant in the body and cause shingles in old age. COVID-19 is potentially no different—science just hasn’t had the opportunity to see and study the long-term effects yet because the disease is so new.

What we do know so far is that COVID-19 is causing a variety of health issues, even in some patients who were not sick enough to be hospitalized by the disease. These issues may or may not be permanent, including scarring to the lungs, heart damage, kidney failure, brain damage, a Kawazaki-like disease in children, and testicular damage leading to male infertility.

Past viruses may even affect the body’s ability to fight future ones. The 1918 flu, or “Spanish flu,” was notable not only because it was a devastating pandemic, but because the fatalities it caused were predominantly in young adults (ages 25–34), as can be seen in the graph below. The dotted line shows normal mortality rates for the seven previous years, while the solid line shows mortality rates during the pandemic.

It is unusual for a virus to affect 25- to 34-year-olds more than infants and the elderly, but scientists have theorized why the 1918 flu was so devastating to the young-adult population: people in this demographic would have been infants during the 1889-1890 “Russian flu,” and their exposure to that virus during infancy may have made their immune systems unable to fight off the “Spanish flu” 28 years later. In other words, these scientists believe that surviving a pandemic as a child could lead to a decreased likelihood of surviving other illnesses in the future.

Natural “Herd Immunity” Only Works if Exposure Causes Immunity

Herd immunity protects those who have not been immunized from catching the disease from those who have. By becoming immune, people are unable to catch and pass on a virus to others, which reduces the chances of those who are not immune from catching the virus. This is why healthcare workers typically receive yearly influenza vaccines, as it prevents them from becoming ill and passing the flu on to their vulnerable patients.

The trouble with herd immunity is that a certain percentage of the population has to become immune to the illness either by exposure or by vaccination. Exposing people to a disease to attempt to reach herd immunity can have deadly results—with an estimated 330 million Americans alive in September of 2020, if 70 percent need to contract the disease for the country to reach herd immunity and 1 percent of those people die, this could mean potentially 2 million American deaths to reach herd immunity without a vaccine.

Even worse, there is no guarantee that exposure to COVID-19 results in long term immunity. In fact, several people have already caught the disease, recovered from it, and been re-infected, showing that long-term immunity from catching the virus may not be guaranteed. If this is true, natural herd immunity through exposure could take even longer and cause even more deaths as people could potentially become reinfected and pass the virus on to others again. It is even possible that like the common cold, herd immunity by exposure to COVID-19 cannot be accomplished at all.

Take What You See On Social Media with a Grain of Salt

There is nothing wrong with reading or watching statements about COVID-19 on social media, but it is important to consider key factors about the statement before deciding if a statement is true. It is important to consider who is making the statement and why, whether the statement includes facts or opinions, what are the sources for the information being presented, what information is being omitted from the statement, whether an expert has a contrary opinion that is backed up with facts, and how any “data” are presented.

If you’re interested in finding out more about how to understand and judge the validity of the data you see online every day, our blog on Understanding and Interpreting Data may be just what you’re looking for.