When Amir Blumenfeld was deciding what to buy for a Secret Santa gift exchange, he landed on something practical: an at-home Covid-19 testing kit. “What better gift is there than peace of mind?” Mr. Blumenfeld, a 38-year-old comedian, wrote in a direct message on Twitter.
At the heart of his quip was an urgent concern: Coronavirus cases are once again rising around the United States as the Delta variant has given way to Omicron, a highly contagious form of the virus. The surge has fueled demand for Covid tests ahead of the Christmas holiday as families seek ways to gather