Memorial Day weekend traditionally marks the start of summer vacation nationwide. This year, vacation travel will be more individual, and a new date might determine the kickoff of many Americans’ summer trips: their vaccination day. At press time, nearly 15 percent of the U.S. population has been fully inoculated against the coronavirus, and as the number climbs, more people will be able to shift from dreaming of getting away to actually doing it. New opportunities are rising alongside the vaccination figures: Several countries and cruise ships are welcoming back visitors with proof of vaccination. Multigenerational travel is also returning, as more grandparents receive the kiss of the needle. Of course, every trip comes with a public service message. The Centers for Disease Control and Prevention still discourages nonessential travel — for now. Sean O’Leary, vice chair of the committee on infectious diseases for the American Academy of Pediatrics, said, “It’s an evolving situation. By summer, the CDC may loosen its guidance.” In addition, the vaccine is not kryptonite against the virus. Vaccinated individuals can still potentially contract and transmit the disease. Children, who are not yet eligible for the shots, are at a lower risk than adults and adolescents of contracting and transmitting the coronavirus, but it’s still possible. With summer on the horizon, here is what you need to know about travel and vaccinations.