Here’s (and how) you’re most likely to get COVID, according to a new study from CU Boulder

Two years into the pandemic, most of us are fed up. COVID case rates are they are more than ever and the hospitalization rate is once again rising rapidly in many countries.

Against this bleak picture, we yearn to be back to normal. We want to meet friends at the pub or take them out to dinner. We want our struggling business to flourish as it did before the pandemic. We want our children to return to their once familiar routine of individual schooling and after-school activities. We want to ride the bus, sing in the choir, go back to the gym, or dance in a nightclub, without the fear of COVID.

Which of these activities is safe? And how safe really? These were the questions we wanted to answer in our own latest research,

SARS-CoV-2, the virus that causes COVID, is mainly spread by air transmission, So the key to stopping transmission is to understand how airborne particles behave, which requires knowledge from physics and chemistry.

Air is a fluid composed of invisible, rapidly and randomly moving molecules, so air particles tend to spread over time indoors, such as in a room or on a bus. An infected person can inhale virus-containing particles, and the closer you are to them, the more likely you are to inhale some virus-containing particles. But the longer you both spend in the room, the more the virus will spread. If you’re outside, space is almost infinite, so the virus doesn’t form in the same way. However, someone can still transmit the virus if you are close to them.

Viral particles can be emitted every time an infected person breathes, but especially if their breathing is deep (such as when exercising) or involves vocalization (such as speaking or singing). Whereas wearing a well-fitting mask Reduces transmission because the mask prevents the release of the virus, which makes a masked infected person who sits quietly in a corner much less likely to infect you than a person who approaches you and starts a heated argument Is.

All variants of SARS-CoV-2 are equally airborne, but the likelihood of catching COVID depends on the transmission (or infectivity) of the variant (delta was more contagious than previous forms, but Omicron is still more contagious) and how many people are currently infected (disease prevalence). As of January 8, the CDC estimates that 98% of COVID infections in the US are caused by the omicron type, While Omicron appears to be more transmitted, it also causes less severe disease, especially in people who have been vaccinated.

likely to be infected

In our study, we determined how different influences on transmission change your risk of getting sick: viral factors (transmissibility/prevalence), people factors (masked/unmasked, exercise/sitting, vocal/quiet) and air- Quality factor (indoor/outdoor, large room/small room, crowded/uncongested, ventilated/unventilated).

We did this by carefully studying empirical data on how many people were infected in superspreader events, where key parameters such as room size, room occupancy and ventilation levels were well documented and showed that a mathematical How is the transmission with the model.

The new chart, adapted from our paper and shown below, gives the percentage chance of being infected in a variety of situations (you can click on it to enlarge it).

Chart showing the risks of contracting COVID in different situations.

A surefire way to catch COVID is to do a combination of things that get you into the dark red cells on the table. for example:

  • Gather with lots of people in an enclosed space with poor air quality, such as a poorly ventilated gym, nightclub, or school classroom
  • Do something loud or rowdy like exercising, singing or shouting
  • drop your masks
  • stay there for a long time.