By Andrea Sachs
Washington - The coronavirus vaccines are welcome news to restless travellers.
But if you're planning to take a trip as soon as you get your shot or shots, depending on which vaccine you receive, not so fast: Vaccinated individuals should wait at least two weeks after their last shot, according to doctors.
And some countries and cruise lines are echoing the call for vaccinated travellers to delay their visits.
Medical experts say the two-week time frame allows the vaccine to do its job. "Our bodies need that time to develop both antibody and cellular immune responses, which are critical for protection," said Paul Sax, clinical director of the Division of Infectious Diseases at Brigham and Women's Hospital in Boston.
Sten Vermund, dean of the Yale University's school of public health in New Haven, Connecticut, said that while the first shot can provide partial protection, it is necessary to wait the prescribed amount of time to reach the highest level of immunity. "To maximise the protection you get from the vaccine, you should be two weeks beyond your second dose before you expose yourself in travel or other somewhat higher-risk circumstances, he said.
The recommendation applies to Pfizer and Moderna's vaccines, which entail two shots, and Johnson and Johnson's, which features a single dose.
In addition, the vaccine's side effects might temporarily dampen any strong urge to leave the couch, much less run off to explore the world. The Centers for Disease Control and Protection warns that the vaccine can trigger headaches, muscle pain, chills, fever and nausea, among other discomforts. The effects can be more intense after the second shot in a two-shot regimen, it notes.
"Some people are going to feel not great after the vaccine," said Emily Landon, an infectious-diseases specialist at the University of Chicago Medicine. "That is really intended. It is the vaccine putting your immune system through its paces, like doing a trial run of combating Covid."
The CDC recommends that all people, including vaccinated folks, avoid non-essential travel, though Transportation Security Administration figures suggest that the public is ignoring that advice: The agency has screened more than 1 million air passengers daily for almost three weeks.
Health-care professionals advise caution when travelling because none of the vaccines is 100% effective against infection, and fully vaccinated individuals can contract and transmit the coronavirus asymptomatically. "There are millions of people who have been vaccinated, and if 5% of them get Covid, that would be a lot of people with Covid," Landon said. "It's just not negligible yet." The rise in variants also poses a concern, because it's not yet clear how much protection the vaccines provide against those more highly transmissible strains.
In good news, a recent study released by the CDC found that the Pfizer and Moderna vaccines cut down on asymptomatic transmission. Even so, the CDC is urging vaccinated individuals to wear masks and socially distance when out in public. "You don't know if the person sitting in seat 16B or 14A is at risk," said Daniel Kuritzkes, chief of the Division of Infectious Diseases at Brigham and Women's Hospital in Boston. "We can't make such fine distinctions yet, so everyone needs to wear a mask."
Another factor travellers will want to take into consideration is how long the vaccines will protect them from Covid-19, the illness that can be caused by the novel coronavirus. Because the inoculations are so new, their lasting power remains a mystery. "There is no way of predicting how long the vaccine will be effective for," Kuritzkes said. However, clinical study participants who received the vaccine months before the general public can provide a clue, according to Landon. So far, protection appears to last at least several months. "They had a head-start advantage," Landon said. "We can see if their antibodies start to come down."
Based on this timeline, Landon said travellers can safely book a vacation for the summer and a few seasons out. But, she advised, every Plan A should come with a Plan B, or at the very least, travel insurance. "I would feel pretty confident in making plans for trips that are six to 12 months out," she said. "But I would not get non-refundable tickets."
Several countries and cruise lines are opening up to vaccinated travellers who have waited after their last shot. Visitors must show proof of the inoculation, which includes the date it was administered, at the start of their trip.
Travellers to Iceland, for example, must present documentation before boarding the plane and upon arrival at Keflavík Airport. Belize is also asking incoming visitors for proof, as is Slovenia, though the wait time varies by vaccine type. Before planning any travel, visit your destination's tourism authority website for entry requirements.
Crystal Cruises, which will begin sailing in the Bahamas in July, is requiring proof at embarkation. Travellers on American Cruise Lines must also present their health record at the time of boarding. However, the US company, which extended its vaccine mandate for departures through April, only requests passengers wait two weeks after one shot, not both.