Science in School: The Science of Pandemic Precautions


Aarna Pal-Yadav, Columnist

During a pandemic, there are a myriad of precautions that we must take to keep ourselves and those around us safe. Our school has been quite diligent in maintaining these pandemic precautions and for good reason: with the coming of winter, it is predicted that the infection rate will rise. But at times, all these precautions – from wearing masks, using sanitizers, and staying 6 feet apart – may feel burdensome. That is because we are simply told to do so, when, in fact, we should be taught how these precautions actually prevent the spread of COVID-19. As Benjamin Franklin once said, “Tell me and I forget; teach me and I remember.” In this article, I will discuss how COVID-19 is spread from person to person and why the various precautions we take work.

COVID-19 is the respiratory disease caused by a species of Coronavirus, SARS-CoV-2. On the left is a (colored) transmission electron microscope image of four virons of SARS-CoV-2. When a viron comes into contact with a cell of the respiratory system, it injects its RNA – which stores all of its genetic information to create proteins, the basis of all life – into the human cell. The cell then starts to express the viron’s RNA and produces viral proteins that, through a complex sequence of processes, causes us to have symptoms such as fever, sore throat, or cough. Then, when an infected person coughs, they release anywhere from 750 to 5,000 respiratory droplets – ranging in size from a micron (1% the width of hair) to the size of a grain of sand – full of SARS-CoV-2 virions into the air at speeds up to 60 mph! Once in the air, these droplets can stay airborne for three hours and, during this time, another person can breathe in the virus from these droplets. Heavier droplets, however, tend to land on surfaces where people can touch and, later, if they touch their face with their “infected” hands, the viral particles can make their way into the person’s respiratory system. And so, the virus spread from one to another.

It’s important to note that a single SARS-CoV-2 viron is really, really small (0.001% the width of hair!) and is not enough to make you sick all by itself. What it can do, however, is replicate like mad and create hundreds, thousands, of copies of itself that, together, can make you sick. The electron microscope photograph on the right shows many SARS-CoV-2 particles (blue) being released from an infected, and now dying, human cell. It is this remarkable, and somewhat scary, ability of viruses to replicate so quickly that has made COVID-19 a global pandemic.

Now that we understand how SARS-CoV-2 can spread from person to via respiratory droplets and infect someone by replicating itself, let’s discuss the various precautions that we can take to prevent COVID-19.

  1. Masks save lives. It’s that simple. It’s been found that masks reduce the chance of catching COVID-19 by preventing airborne SARS-CoV-2 droplets from reaching the mouth and nose of wearers. The N95, the gold standard of all masks, protects wearers by filtering out 90% of airborne particles that measure more than 0.3 µm. Research on the efficacy of basic surgical and cloth masks is ongoing, but scientists agree that these masks help prevent wearers from inhaling virus-containing droplets. Not only do masks protect their wearers, but they also prevent people who are infected from transmitting viral droplets to others. The projections are hazy, but research suggests that if 95% of Americans wear protective masks, 100,000 lives could be saved in the coming months. This is assuming that people wear masks correctly: they must cover your nose and mouth to be effective! So many people, too many people, let their masks fall off their nose, but this ruins the entire purpose because then, viral droplets can be inhaled through the nose.
  2. Social distancing prevents the spread of COVID-19. This makes sense, considering that close contact with infected individuals is how viruses spread from person to person. The further one is from everybody else, the less likely they are to inhale a viral droplet from an infected person. We’ve all heard that 6 feet apart is the way to go with social distancing, but this may not be enough. A study published in JAMA suggests that the viral droplets emitted from a sneeze can “span approximately 23-27 feet.” Research on this is ongoing, but it’s better to be safe than sorry: stay as far away from people as possible!
  3. Sanitizer works by killing viruses and bacteria on surfaces so that people don’t get sick from touching infected surfaces. This is different from mask wearing and social distancing which prevents the spread by preventing people from inhaling airborne viral particles. Washing one’s hands with soap and warm water is and has always been the best way to sanitize, but when that’s not possible, use other sanitizers. Alcohol-based sanitizers are generally superior to alchochal-free ones because they destroy the protective envelope protein of viruses.

So now you know how COVID-19 spreads from person to person and why mask wearing, social distancing, and sanitizing is so important. I’m not going to tell you “Wear a mask!”, “Social distance!”, and “Sanitize!” as we’ve all been hearing recently, but what I am going to say is that these simple actions can save lives. I hope you take these precautions to heart now that you know the science behind them.