That may not be measurable with antibodies, which wane after several months. But when the T cells and B cells in your immune system are stimulated, Rutherford says, “all the memory comes back right away.”
Acquiring Covid-19 naturally leads to developing antibodies that recognize and fight off the virus when they see it again. If you’ve been re-exposed, “those people have really, truly robust immune systems,” said Dr. George Rutherford, an epidemiologist at the University of California, San Francisco.
Rutherford, like Russo, is concerned about the variants. “The question for me about this long-term immunity stuff is not how long it lasts,” Rutherford said, “but how specific it needs to be for these different strains.
How safe are airplanes and other modes of travel?
The air inside airplanes is quite clean: It’s heavily filtered and regularly replaced, much like the air in an operating room. When I was flying, I took the advice of Dr. Angela Rasmussen, a virologist, and turned on the vent above my seat. “The more ventilation you can introduce into your space, the better,” she told me in an interview late last year.
Rasmussen, and other experts I’ve interviewed, also warned me to be cautious of the crowding that tends to happen during air travel. While sitting in your seat, mask on, is likely safe because of the powerful air filtration, the cramming of bodies that tends to happen when people enter and exit the plane can make you a bit more vulnerable. This is where maintaining distance however you can – including letting the crowd go by while you wait for some space – is helpful. So is wearing a good mask.