Omicron BA.5 May Increase the Risk of Outdoor Transmission—Here's How to Stay Safe

Omicron subvariant BA.5 may be the most contagious version of the SARS-CoV-2 virus that we've seen yet—and even situations that have seemed relatively low-risk as of late, like outdoor gatherings, may now pose a greater threat.

According to the latest data from the Centers for Disease Control and Prevention (CDC), BA.5 accounts for 65% of all COVID-19 cases in the U.S.; in just two months, the subvariant managed to outcompete BA.2 and BA.2.12.1—the two previously dominant subvariants.

"BA.5 is currently the predominant strain in circulation," epidemiologist Matt Weissenbach, DrPH, senior director of clinical affairs at Wolters Kluwer Health, told Health. "It is more transmissible than other previous variants because it can evade previous immunity from COVID infection and vaccination."

It's this increased transmissibility that can make activities that were previously thought of safer (but not completely risk-free) options, more risky. Outside gatherings are a prime example of this.

"Being outdoors in the outside air absolutely protects us from less transmissible viruses," Sharon Nachman, MD, Chief of the Division of Pediatric Infectious Diseases at Stony Brook Children's Hospital, told Health. "But for something that's very efficient at spreading like BA.5 is, it won't be as protective."

Here, experts discuss just how contagious BA.5 is—and how you can go the extra step to protect yourself, even during outdoor activities this summer.

How Contagious Is BA.5?

BA.5 is just one of the latest subvariants to come from the original Omicron lineage, Michael Blaivas, MD, chief medical officer at Anavasi Diagnostics, told Health. All variants and subvariants have changes in their genetic code, compared to the original virus they came from.

According to Dr. Blaivas, it's helpful to think of these changes in BA.5 (and other variants that have outcompeted their predecessors) as "upgrades" to make them better fit to survive (aka, infect humans).

"The mutations of BA.5 impact its spike protein in part and result in some important 'upgrades' in the ability of the virus to infect humans more quickly and also attach to the lungs," Dr. Blaivas said. "These 'upgrades' in viral performance mean the virus can spread more quickly than prior variants."

BA.5's mutations have also allowed it to sneak past the body's immune system more easily. Even past infection or immunization don't offer quite as much protection as would be expected. According to an Epidemiological Update from the European Centre for Disease Prevention and Control (ECDC), "the current growth advantage for the BA.4 and BA.5 variants of concern…compared to the dominant variant BA.2 is probably due to their ability to evade immune protection against infection induced by prior infection and/or vaccination, particularly if this has waned over time." Overall, the ECDC said this makes more frequent breakthrough infections and reinfections possible with BA.4 and BA.5.

So far, however, BA.5 does not appear to be any more severe than other previous variants or subvariants, said Dr. Blaivas.

Can You Get BA.5 Outdoors?

The short answer here is yes, you can get infected with the BA.5 subvariant, even in outdoor settings.

"When a variant is slated to be more or less transmissible than another, it applies as a blanket statement regardless of setting,'' said Dr. Weissenbach. Although outdoor settings are overall the safer option, when a virus is more contagious, it's more contagious in any setting.

It's also important to say that outdoor gatherings were never completely risk-free—they were just less risky. "We were never safe from getting infected with a virus outdoors, it was just less likely," said Dr. Blaivas.

Now, since everyone is spending more time outside because of summer and there is a very transmissible virus circulating, people may be getting infected with BA.5 outdoors more frequently.

"Most people that get it outdoors are still getting into groups with friends, neighbors and family when outdoors and that is a good way to spread infection when it is present," he said.

How to Protect Yourself During Outdoor Events

Generally speaking, the same factors that influence your risk of infection indoors, also apply to outdoor settings. Physical distancing, exposure time, and protective measures can all influence your likelihood of getting infected with COVID-19—or avoiding the virus.

"If you're standing outside, shoulder-to-shoulder with hundreds of unmasked strangers [for an extended period of time], it certainly has the potential to mimic a cramped, indoor setting," said Dr. Weissenbach. In fact, it "could likely be more risky than an indoor setting under different circumstances with proper social distancing and other preventive measures," he added.

According to Drs. Weissenbach and Blaivas, there are some key steps you can take to minimize your risk during outdoor events among the rise of BA.5 cases. The first is arming yourself with information about community levels in the area to which you're traveling; the CDC's community levels tracker can give you county-by-county information on hospital admissions and COVID-19 case counts. If a community level is high, you may want to reschedule your trip or be extra cautious.

If you are attending an outdoor gathering—even when community levels are medium or low—you should still be cautious about masking and social distancing, especially in large crowds. Regular testing after potential exposure and remaining up to date on vaccines and boosters are also necessary steps, regardless of whether you're indoors or outdoors.

You'll also want to consider your own personal risk for COVID-19, that of those close to you, and your combined risk tolerance for public situations.

"If you are young and healthy, then the risk from COVID remains very low, just like before, but that may not be the case for older and chronically ill people," said Dr. Blaivas. "If you are young and healthy or fully immunized, BA.5 may still make you feel pretty rotten for a while and some people can get very sick from it, so know your risks."