Esther Greenberg's Passover seder is rooted in centuries-old tradition, but it’s a modern medical breakthrough that’s bringing together her vaccinated, unmasked family for this weekend's holiday meal after being long separated by Covid-19.

“Hugging is definitely on the menu,” said Greenberg, 74, a grandmother who like her husband Bob, 76, a retired pharmacist, was fully vaccinated against the air-borne virus, which has killed more than 543,000 people in the United States.

With more than 42 percent of all American seniors already fully inoculated against Covid-19, vaccinated Jewish grandparents forced to hold seders on Zoom last Passover are emerging to embrace loved ones around the seder table during the weeklong celebration that begins on Saturday...