Photograph by Sergei Malgavko, TASS/ Getty Images
The day will come when everyone who wants a COVID-19 vaccine will be able to get one. Then people might wonder about a question that once seemed far-fetched: Should I get a second just to be safe?
As the pandemic rolls on, that actually might be an option, as more vaccines make their way through the approval pipeline in the coming months. On Friday, the U.S. Food and Drug Administration authorised emergency use of a vaccine by Moderna—just a week after it granted similar authorisation for one by Pfizer and BioNTech, the vaccine currently being rolled out in the U.K.