The new coronavirus knows no national borders or social boundaries. That doesn’t mean that social boundaries don’t exist.

“En route to Paris,” Gwyneth Paltrow wrote on Instagram last week, beneath a shot of herself on an airplane heading to Paris Fashion Week and wearing a black face mask. “I’ve already been in this movie,” she added, referring to her role in the 2011 disease thriller “Contagion.” “Stay safe.”

Ms. Paltrow did not pose with just any mask, unlike, say, Kate Hudson and Bella Hadid, who also recently posted selfies wearing cheaper, disposable masks. The Goop founder and influencer of influencers instead opted for a sleek “urban air mask” by a Swedish company, Airinum, which features five layers of filtration and an “ultrasmooth and skin-friendly finish.”

Never mind that the surgeon general, Jerome M. Adams, begged people to refrain from indulging in mask mania on Twitter last weekend. Priced from $69 to $99, the Airinum mask, which has been popping up on Instagram stylistas, is sold out on its website until April. (The MoMA Design Store, which carried the mask, is also sold out.)