Facing a second spring without the promise of a break, frustrated would-be travelers can be forgiven for feeling weary. But, infectious-disease experts say, there are better days for travel ahead as the number of vaccinations increases and new coronavirus cases drop.

Exactly when that will happen — and what those days will look like — is unclear. And unknowns still loom: How long will immunity last after people are vaccinated or infected? Can they still transmit the virus? Will vaccines work as well as new variants emerge?

What experts can say is that travel will be safer for some people, and in some places, sooner rather than later. They also agree that “normal” is a long way away.

An infectious-disease professor isn’t sure travel will ever be like it was in 2019

David Freedman, a professor emeritus of infectious diseases at University of Alabama at Birmingham and an expert on travel medicine, said travelers who want zero risk of the coronavirus could be in for a significant wait.

“That type of traveler may not be able to travel for a long time, if ever,” he said, especially if they’re not willing or able to get the vaccine.

He said he anticipates “a ton” of domestic travel this summer and for restrictions in certain states to relax as more people get vaccinated. As for travel between countries, he suspects that could start by late fall or the end of the year.

As for a return to some kind of normal across the globe? “That’s real crystal-ball stuff,” Freedman said.

He said he is not sure travel will ever look like it did in 2019.

“How close we can get, I don’t know,” he said, given physical changes that have been put into place to address the pandemic. “I just can’t see it going back to normal for a long, long time. … I just can’t see it happening in the next 3-5 years.”

A public health expert thinks vaccinated travelers can hit the road safely

Leana Wen, an emergency physician and public health professor at George Washington University, said there are some who could consider travel safe even now.

“If people are fully vaccinated and really want to visit loved ones they haven’t seen in a while, they are protected by the vaccine,” she said. “If they add additional precautions like adding masks, that travel is very safe. I do think that it’s important for people to get back to some sense of normal.”

Wen, the former health commissioner for Baltimore and a Washington Post contributing columnist, said the top question she gets is what vaccinated people can do.

Her advice is that if one vaccinated household wants to visit another, they should feel free to do that with no restrictions — hugs, eating indoors, all the things we’ve been told not to do. That gets more complicated, she said, if only one member of a household has gotten the vaccine or the visit is to see people who are not yet immunized.

“If the main reason why the visit did not occur earlier was out of concern to the grandparents and the grandparents are now vaccinated, I think many families can decide that that’s worth the risk,” she said.

Wen said fully vaccinated people should still be cognizant of local restrictions and abide by them if they travel: “If somebody is fully vaccinated and they’re saying, ‘Let me throw away my mask and fly across the world and go bar hopping,’ that’s not responsible,”

A senior Johns Hopkins scholar warns recovery will be uneven

Eric Toner, a senior scholar with the Johns Hopkins Center for Health Security, said people who have not been vaccinated should not be traveling yet.

For those who have gotten both shots and waited the two weeks for protection, he said, they should look for destinations where vaccination programs are robust, statistics are reliable and positivity rates are low — 5 per 100,000 people or less.

He said Europe will probably be one of the first places that will be safe to visit, but he’s not sure when that will be.

“Maybe the summer; we’ll just have to see,” he said. “I wouldn’t book a flight yet.”

For other parts of the world, including Africa, South America and parts of Asia, he expects it to be a very long time before travel can resume in any kind of normal way.

“I think what we’re going to find is that things are going to be very uneven,” Toner said. “There’ll be parts of the world where the vaccination rates are very high and where we’ll feel perfectly comfortable traveling without wearing a mask, and other countries where vaccination rates don’t get as high and may never get as high as we’d like, in which case masking and distancing would still be required.”

Domestically, he also advised that only people who have been vaccinated or infected with the virus travel this summer.

“Even though a lot of people have been infected and a lot of people have been vaccinated, it’s probably still not the majority of people,” Toner said. “Your risk of getting infected is still big enough that I don’t think I would recommend people taking that risk.”

A health intelligence analyst strikes a note of caution

Courtney Kansler, senior health intelligence analyst with risk management firm Crisis24, said she anticipates more domestic travel and travel between countries with access to vaccines in mid-to-late 2021.

But, she said, she doesn’t anticipate anything to resemble “normal” until at least 2023.

“This is probably the part of the answer that no one really wants to hear, because it’s also pretty depressing,” she said.

Because it will still take time for vaccines to be distributed globally — and science is still not clear on how long the vaccines give immunity — it’s hard to predict a long-term future for travel. She said she would expect it to be two to three years for the world to catch up.

“I don’t mean to rain on your parade,” Kansler said.

An epidemiologist highlights the issue of vaccine equity

Saskia Popescu, an infectious-disease epidemiologist, said in an email that for travel to start to look more normal, there should be global distribution of vaccines, a pattern of decreasing or low community transmission, and an absence of new variants that complicate any kind of intervention.

“It’s more of a checklist rather than a single variable,” she said.

Popescu said that while the trajectory right now shows improvement, with cases going down and vaccines getting into arms, there are still challenges to deal with — including local and worldwide vaccine equity. Given that, she said she believes it could be until 2022 for that checklist to be filled out.

“Vaccine equity is a huge issue right now, and I highly encourage people to be mindful of this as they look to travel internationally,” she said.

Popescu encouraged travelers to consider the state of things in both the place they’re leaving and going.

“We need to be mindful of going from an area of high transmission to one that is low, where we could potentially be bringing covid into an area that is not experiencing much local transmission or even has limited access to public-health interventions like testing or vaccines,” she said.