Right now, most of us, if not all, know someone who has contracted COVID-19, or at least been exposed to it. A family member, a friend of a friend, a colleague. COVID-19 is everywhere. And the experience often unfolds differently from person to person.
Some people are briefly exposed to the virus and develop a serious and life-threatening infection. Others spend hours without knowing it with an infectious person and develop a mild illness. And a lucky handful that is directly exposed to someone infected with the virus never gets infected.
Experts suspect that there is a mix of factors affecting how sick people become ill after being exposed to the coronavirus. There’s our age and genetics as well as the underlying health issues – but viral load and the circumstances we’re exposed to play a pretty big role as well.
Being exposed to a high viral load usually leads to more brutal use. There are ways to minimize the amount of virus you inhale, so even if you are exposed you will hopefully be less sick.
Here’s why viral load is important:
A high viral load can make you sicker
Evidence shows that viral load, or the amount of virus a person is exposed to, can influence a person’s degree of illness.
The best data we have on viral load comes from animal studies. They taught us that in general, the more an animal is exposed to the virus, the sicker it will be, said Benjamin Neuman, virologist and head of the biology department at Texas A&M University-Texarkana.
A Syrian study carried out in hamsters found that animals given a higher SARS-CoV-2 viral load had more severe lung damage and greater weight loss. With both SARS and SEAS, two deadly coronaviruses behind past outbreaks, being exposed to higher infectious doses has led to worse outcomes.
“Viral particles are like lottery tickets,” Neuman said. “The more exposed you are, the more likely you are to contract the disease.”
“Viral particles are like lottery tickets. The more exposed you are, the more likely you are to catch the disease. “
– Benjamin Neuman, virologist
There are many reasons why the viral load influences the severity of a disease. First of all, more viruses are able to infect more cells, so from the start our immune system is ready for a tougher fight.
Neuman said that a large viral load also likely has more viral diversity. “A larger number of viruses will generally have a wider range of mild genetic variants. Infection with virus pools containing more mutations also results in more disease, ”he explained.
Other factors that determine the severity of the disease in addition to the viral load
Viral load alone will not determine how sick people are. OOther factors such as age, comorbidities and genetics play an even more important role, according to Ilhem Messaoudi, the director of the University of California, Irvine’s Virus Research Center.
“The host plays a much more important role in the trajectory of clinical disease,” Messaoudi said.
The circumstances in which a person is exposed are also worth considering. For example, an intensive care doctor operating on an infected person has a much higher risk of being exposed to a high viral load compared to someone passing an infected person at the grocery store, Messaoudi explained.
Spending time indoors near someone with a high viral load who is losing a ton of virus also increases the risk of catching COVID-19. Some small studies suggested that people with a high viral load may be more likely to pass the coronavirus to others, but more research is needed to better understand the link.
Researchers have not been able to quantify the viral load and determine when the viral load becomes problematic. “There is no magic threshold,” Messaoudi said, but ultimately it doesn’t take much for a person to be infected.
Whether we realize it or not, we are coughing up droplets at each other all the time. “Every time you switch to talking to someone without a mask, you’re going to exchange saliva,” Messaoudi said. If a few good viral particles get into our lungs and our body does not generate a robust antiviral immune response in time, infection can occur.
How to reduce the amount of viruses you are exposed to
Masks are currently our greatest weapon against the coronavirus.
Studies have shown that face masks can potentially limit the amount of virus exhaled into the environment and inhaled. This is great news when it comes to viral load.
A study (also carried out on hamsters) found that a surgical mask septum greatly reduced the chances of rodents getting sick, and if they did get sick, the disease was milder. “We can’t say for sure yet, but it seems reasonable to suggest, based on studies of animal infections, that reducing the dose of coronavirus could lead to less severe infection,” Neuman said.
The message is simple: hide yourself. Even when people around you are wearing masks and even when you are in an empty space, others use them frequently. “If you are in a place where another person has been recently, wearing a mask is a really good idea,” Neuman added.
“Masking can prevent up to 70% of transmission, which is equivalent to one dose of vaccine.”
– Ilhem Messaoudi, director of the University of California, Irvine’s Center for Virus Research
Remember: the coronavirus is known to spread via aerosols that can hang in the air for a few hours, so a good mask could protect you from inhaling some of these floating particles. “Masking can prevent up to 70% of transmission, it’s basically as good as a dose of the vaccine,” Messaoudi said.
Ventilation is another useful tool that helps disperse viral particles and break down viral loads.
Being outside or opening windows reduces the chances of contracting COVID-19 by “effectively diluting the virus in more air and quickly removing respiratory droplets from an enclosed space,” Neuman said.
You will always have to be careful. Ideally, the wind or fans will carry and scatter the virus particles away from you, but depending on the airflow patterns, you could still be in danger and inhale enough virus to get sick.
Finally, if any of your contacts have been exposed, isolate yourself from them for about 10 days – even if they don’t seem sick – is a must.
People tend to have the highest viral loads just before or around the day. onset of symptoms, so while they may appear to be COVID-free, they also have the potential to expose you to a ton of viruses.
Experts are still learning about COVID-19. The information in this story is what was known or available at the time of publication, but directions may change as scientists find out more about the virus. Please consult the Centers for Disease Control and Prevention for the most recent recommendations.