BA.5—the omicron subvariant that emerged in South Africa in February before sweeping across the world—is now the dominant coronavirus variant in the United States. Thanks to a unique cluster of mutations on the spike protein, the part of the virus that latches to our cells, BA.5 is believed to be the most contagious strain of SARS-CoV-2, the virus that causes COVID-19, so far.
And it has been able to spread fast. According to the Centers for Disease Control and Prevention (CDC), the subvariant is causing approximately 65% of the country’s COVID-19 cases at the time of publication.
It’s no surprise, then, that more and more stories have emerged of people speculating that they caught COVID-19 outside, which can be a bit unsettling to hear as cases continue to rise in many parts of the country. The outdoors were originally believed to be the safest setting for social gatherings at the height of the pandemic, but you may be wondering if that’s still the case with BA.5. Ahead, experts explain what you need to know about this subvariant, outdoor transmission, and staying safe as you enjoy your summer.
Back up: Why is BA.5 such a big deal right now?
BA.5 caught the attention of public health experts after it quickly displaced the very-transmissible BA.1 and BA.2 omicron subvariants. Though the BA.5 wave hasn’t caused a significant spike in hospitalizations or deaths in South Africa, certain locations hit by BA.5, like Portugal, have seen an uptick in hospitalizations. Upon taking a closer look at the new subvariant, scientists discovered that BA.5 has mutations in the spike protein that may allow it to evade the immune system’s first line of defense—antibodies—raising the likelihood that it’ll cause a new wave of infections and reinfections, especially in people with low or waning immunity.
However, early evidence suggests that the vast majority of people with some immunity, either from prior COVID infection or vaccination, will continue to be protected from severe illness, according to preliminary research. Data from South Africa found that two doses of the vaccine provided up to 87% protection against hospitalization with BA.5, as Bloomberg reported. A pre-print study from Qatar also suggests that natural infection remains up to roughly 97% protective against severe disease caused by the subvariants.
So, should you be worried about outdoor transmission as BA.5 surges?
Experts say outdoor transmission has always been a thing—with alpha, delta, omicron, and now BA.5. “Yes, you can catch BA.5 outside, but it’s more likely that you’ll catch it indoors than outdoors. This was true for the other variants, too,” Linsey Marr, PhD, a professor of civil and environmental engineering at Virginia Tech who studies viral transmission, tells SELF.
Outdoor activities are inherently safer than indoor gatherings, says Dr. Marr. But BA.5’s heightened transmissibility will ultimately lead to more indoor and outdoor spread. “It appears that outdoor transmission has become more likely with the newer variants over the past year (i.e. since delta), as they have become more transmissible, but outdoors remains a much lower-risk setting than indoors,” Dr. Marr explains.