As the world scrambles to understand the severity of the new omicron variant, dozens of countries – including the United States – added travel restrictions to curb the spread of the variant.
But are they effective?
Experts who spoke to USA TODAY agreed that it could help buy time to build a response to the new variant, but travel bans wouldn't stop the spread. Another concern experts shared was the possible effects on the future of being forthcoming with variants – a concern already voiced by leaders in the World Health Organization.
"I think (travel bans) may give us more time, but they're not going to prevent (spread) – the cat is out of the bag," Dr. Walter Orenstein, associate director of Emory Vaccine Center and professor of infectious diseases at Emory University School of Medicine, said. "There are so many countries already who have cases of this, but what it could mean is there would be fewer introductions into other countries which may slow it down and give some time for us to respond depending on what we see."
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That time, experts said, could help vaccine makers tweak vaccines to be more effective if needed – and see if the current vaccines are effective against the strain. It could also give Americans more time to get their first round of vaccinations or boosters.
President Joe Biden said Monday during remarks about the omicron variant that "it's almost inevitable there will be, at some point, that – that strain here in the United States."
"I think the way they're implemented make people feel safe but you're probably not as safe as you think you are related to the travel ban. Because it's not preventing all cases from coming in," Dr. Danielle Ompad, associate professor of epidemiology at the NYU School of Global Public Health, said.
For Joseph Eisenberg, a professor in the Department of Epidemiology and professor of Global Public Health at the University of Michigan, the travel ban could help buy some time for vaccine makers, but there could be a big cost in future reporting of new strains.
"The cost-benefit obviously is if the ban results in these countries being less likely to do this kind of surveillance and provide this kind of information that's incredibly valuable about new strains because they don't want these repercussions of having these travel bans, then the net may be a negative with a respect to the future," he said.
When asked about the travel ban as a deterrent for countries to come forward with information, Biden said he doesn't "think that's what's going to happen ... We needed time to give people an opportunity to say, 'Get that vaccination now.' "
Nations around the world move swiftly on travel bans
Dozens of countries have announced new travel bans since omicron was named a "variant of concern" on Friday.
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On Friday, the European Commission asked European Union member states to activate an "emergency brake" on travel from South African countries and other nations affected by the omicron variant. Many European countries have tightened restrictions, including Spain, Greece and France.
Other countries, including Israel and Japan, have also announced new travel restrictions this week.
Some nations are continuing to move forward with reopening plans, including New Zealand, which has had some of the most stringent entry requirements throughout the course of the pandemic and has not yet reported a case of the omicron variant. The country is set to reopen to foreign travelers on April 30.
"There will be no new restrictions on travel between regions," New Zealand Prime Minister Jacinda Ardern said Monday. "But COVID-19 is still with us, and the emergence of the omicron variant overseas is a reminder of why we need to maintain a careful approach and keep public health measures in place to protect us."
In the meantime, experts said, the best defense against the new variant was to get more of the population vaccinated – and for those eligible for booster shots to get them.
How long should the travel ban last to slow the spread of omicron?
If the travel ban does prove to be effective in slowing the spread of the new variant to the U.S., Orenstein said the length of the ban should depend on the epidemiology. If the spread in the U.S. is slow, it would make some sense to keep it in place. But if the spread in the U.S. accelerates despite the ban, it doesn't make sense to keep it.
"It's so hard," Orenstein, professor of infectious diseases, said when asked how long the travel ban should be. "The answers are very very tough. The joke I like to make is it's so much easier to be a historian and look back at what you should have done as opposed to having to make history without having all of the information you ideally want to know to make a good decision."
When asked how long the new travel bans may be in place on Tuesday, Jeff Zients, White House COVID-19 response team coordinator, said health officials will make recommendations based on the virus's transmissibility, severity and vaccine effectiveness against the new strain.
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What other measures is the US taking to slow the spread?
In addition to the new travel bans, the Centers for Disease Control and Prevention is expanding an XpresCheck biosurveillance monitoring program to identify new and existing COVID-19 variants from certain international travelers.
The program launched in September at John F. Kennedy International Airport, Newark-Liberty International Airport and San Francisco International Airport and provided testing for travelers arriving from India. It began testing passengers from South Africa on Sunday and is expanding to Hartsfield-Jackson Atlanta International Airport.
The program is "enhancing our surveillance for the omicron variant," CDC director Dr. Rochelle Walensky said Tuesday. "We are also actively working with the airlines to collect passenger information that can be used by CDC and local public health jurisdictions to enhance contact tracing and post-arrival follow up should a case be identified in the traveler."
This article originally appeared on USA TODAY: Omicron travel ban: Will it help slow the spread of the COVID variant?