Are You Safe In The Open Air? Here's The Science Behind The CDC's New Mask Guidelines
When the CDC loosened mask guidance for outdoor activities this week, it did so based on high vaccine effectiveness and on evidence that transmission of COVID-19 is far less frequent in the open air.
Vaccinated people can now safely gather, mask-less, with friends and family outside, and even unvaccinated individuals can take off their mask while walking, running, or biking with their household, or at small gatherings of fully vaccinated people.
The CDC still warned that vaccinated people should keep their masks on in crowded outdoor settings, such as a parade or concert, and experts caution there are other scenarios where masking outdoors may still be a good idea because outdoor transmission isn't impossible.
Evidence Behind CDC Mask Guidelines Loosening
Studies have shown that people are far less likely to catch COVID-19 outdoors, but experts say that not all outdoor activities carry the same risk.
Factors like crowd density, air flow, and weather patterns can all determine how the virus spreads. They can also be used as metrics to inform people about which precautions they should take in outdoor settings.
Early research established that spending time outside reduces risk of COVID-19 infection. A systematic review published in February in the Journal of Infectious Diseases found that less than 10% of all COVID-19 cases were transmitted in outdoor settings, and that the risk of transmission indoors was almost 20 times higher than it was outside.
An author of the review has added that in some of the studies included in the review, outdoor transmission was probably even lower than 10%. Some of the infections occurred at construction sites or summer camps, which could have been both indoors and outdoors.
Additional data from the Health Protection Surveillance Centre in Ireland showed that just 262 of over 200,000 infections occurred outside -- just 0.1% of all cases.
Is It Even Possible To Catch COVID Outside?
The virus spreads most commonly by breathing it in from the air, usually coming from people nearby or sometimes farther away if you are in a poorly ventilated room. Outdoors, the virus cannot accumulate in the air; it quickly becomes diluted in the atmosphere, like a drop of dye in the ocean.
While the risk is small, there is still a risk. It's important in these types of situations to remember that the small risks we take could mean the ultimate risk for someone we love.
What Are The New Mask Guidelines For Americans?
People vaccinated against COVID-19 are no longer required to wear masks outdoors in most settings, according to the new guidelines set by the CDC.
Fully vaccinated people can now "gather or conduct activities outdoors without wearing a mask, except in certain crowded settings or venues."
Safe activities include being outdoors with members of your household, attending small outdoor gatherings with vaccinated and unvaccinated people, and dining outdoors at a restaurant with friends from multiple households.
While the agency graded attending a crowded outdoor event like a live performance, parade, or sporting event as "safe" for vaccinated individuals, they still recommend masking during these events.
CDC updated masking guidance for unvaccinated individuals as well -- noting that even those who are unvaccinated can now "walk, run or bike outdoors with members of your household" and an unvaccinated individual can "attend a small, outdoor gathering with fully vaccinated family and friends" without a face covering.
Unvaccinated people should continue to wear masks when attending small outdoor gatherings with a mix of fully vaccinated and unvaccinated people, though CDC grades this activity as "safe."
They should also continue to wear masks when dining outdoors at a restaurant with friends from multiple households (graded as "less safe") and when attending crowded outdoor events (graded as "least safe").
Is The End Of COVID-19 In Sight?
With the CDC's new mask guidelines, it's beginning to feel like the years long, global battle against a virulent pandemic is reading its final chapters. Still, variants of the original virus continue to pop up around the world. These new variants pose a threat as humanity struggles to protect themselves against the different strains and their unique protections.
Worldwide vaccine rollouts are in play this very minute, but will they come too late for too many? In order to achieve herd immunity against these viruses, the population of Earth must vaccinate itself at an aggressive pace for the coming year(s).
It's difficult to say if the end is in sight, but after a year of turmoil, isolation, and loss, it's fair to say that the CDC's latest update is a small victory that feels like a whole lot more.