CNN  — 

Governments are trying to buy time with a rash of new travel restrictions as they figure out the potential impact of Omicron.

But the restrictions are being criticized by some officials and medical experts as ineffective and potentially damaging to global coronavirus tracking.

“I think this is really an illusion of protection,” CNN medical analyst Dr. Jonathan Reiner said Monday.

“The metaphor that I have been using – it’s like locking a screen door. You feel like you’ve done something to protect yourself, but you really haven’t,” the professor of medicine and surgery at George Washington University told CNN’s Kate Bolduan.

“I’m not sure what this ban will achieve, other than to add some disincentive to other countries that might be looking to do intense sequencing and identify variants,” Reiner said. “This might incentivize those countries to maybe, you know, back off on that a little bit because no good deed goes unpunished.”

The World Health Organization’s Regional Office for Africa said Sunday that it stands with African nations and called for borders to remain open as an increasing number of countries around the world impose flight bans from southern African countries.

The office said countries should take a risk-based and scientific approach and put in place measures that can limit the variant’s possible spread.

“Putting in place travel bans that target Africa attacks global solidarity,” WHO Regional Director for Africa Matshidiso Moeti said. “Covid-19 constantly exploits our divisions. We will only get the better of the virus if we work together for solutions.”

Travel restrictions may play a role in slightly reducing the spread of Covid-19 but “place a heavy burden on lives and livelihoods.”

Studies show that travel restrictions may only slow the introduction of a new virus or variant by a few weeks, and WHO has repeatedly expressed fears that travel bans hurt economies and discourage countries from being forthright about reporting new viruses or variants.

Holes in the strategy

The restrictions imposed by the US barring travelers from southern Africa may slow transmission, but they highlight holes in the country’s new rules, some medical professionals say.

There’s an “intuitive attraction” to restricting travel, says Dr. William Schaffner, a professor of infectious diseases at Vanderbilt University Medical Center.

“‘Gee, the bad viruses are there, let’s put down an iron curtain and prevent the virus from getting here,’ but travel restrictions are not very restrictive,” he said.

In fact, they’re very porous for several reasons.

For one, the United States’ new restrictions still allow US citizens and legal permanent residents coming from the affected countries in southern Africa into the United States.

“What makes anybody think that they couldn’t bring the virus with them?” Schaffner said. It’s similar to the earliest restrictions in 2020 curtailing travel from China, he said. “Americans kept coming back, and they brought the virus with them.”

Travelers queue at a check-in counter at OR Tambo International Airport in Johannesburg on November 27, 2021, after several countries banned flights from South Africa.

A study last year from the US Centers for Disease Control and Prevention showed that the US bans imposed in early 2020 came too late to stop the virus from getting to the US.

A spring 2020 study in the journal Science showed that the original restriction of travel within China after the novel coronavirus was first discovered in Wuhan only slowed the progression of the epidemic by three to five days in China.

That same study showed that international travel restrictions helped slow the spread of coronavirus to the rest of the world until mid-February, but it also suggested that other mitigation measures (such as early detection, household quarantines and hand-washing) would be more effective than travel restrictions at curbing the pandemic.

Foreign travelers to the US have to be fully vaccinated and tested before arriving in the US, and those kinds of measures are effective at reducing the import of viruses, Reiner said.

Biden: Ban in place ‘to give us time’

On Monday, President Joe Biden said the purpose of the ban on travel from certain southern African countries is “to give us time to get people to get protection. To be vaccinated and get the booster. That’s the reason for it.”

He acknowledged on Twitter on Monday that “while we know that travel restrictions can slow the spread – they cannot prevent it. We will have to face this new threat.”

CNN Medical Analyst Dr. Leana Wen says the Biden administration should have gone much further with its restrictions by requiring returning travelers to quarantine and retest after arrival.

Canada has implemented quarantine and post-arrival testing for citizens and residents returning from some African countries. And the United Kingdom has instituted a mandatory hotel quarantine for residents and citizens returning from countries on the UK’s red list. (See a full list of new travel restrictions by country here.)

Since Omicron sequences have been found in numerous other countries beyond southern Africa, “there should be an across-the-board quarantine and retesting requirement,” said Wen, who is an emergency physician and visiting professor of health policy and management at the George Washington University Milken Institute School of Public Health.

“If implemented correctly, (travel restrictions) do work in slowing down the rate of transmission,” she said. “It only works, though, if there aren’t substantial loopholes as there currently are in the US travel ban.”

The nature of the virus means restrictions are not a magical solution.

“We’re dealing with an extraordinarily contagious respiratory virus, and history tells us that bans, restrictions, etc., only give us a little bit of time, if that, because these are so contagious that they will spread,” Schaffner said.

And “there’s always an element of closing the barn door after the horse has escaped,” he said, noting that it’s “only a matter of time” before the Omicron variant is discovered in the United States.

‘Knee-jerk’ reaction criticized

Salim Abdool Karim, an epidemiologist and former co-chair of the South African Ministerial Advisory Committee on Covid-19, told CNN’s John Berman on “New Day” on Monday that travel bans are “outrageous” and will have little, if any, impact on stopping the spread of the new Omicron variant.

“Firstly, it’s outrageous that South Africa and southern Africa is being punished for having good surveillance and, you know, ensuring that we wanted to be completely transparent and to share this data with the rest of the world as soon as we knew it and confirmed it,” Karim said, when asked about travel restrictions put in place and how effective they were.

“If you think about … what we’ve experienced with the Delta variant, within a matter of three weeks it was in over 53 countries, so it’s going to become superfluous and irrelevant to try and block travel from, you know, a few countries because it will be spreading in many other countries,” he said.

“Indeed, by the time we got to know about it, which was pretty quickly given that the first patient was probably in our system about the ninth of November, that we’re looking at transmission has probably seeded itself in most countries.”

The early “knee-jerk reaction” to block travel will slow the spread slightly at best, Karim said, but will probably have “little if any impact” because there is already a good approach to preventing the spread of the virus through air and sea travel.

This involves five key components, he said. Ensuring that vaccinated people are the only ones traveling, that they have a negative PCR test, are asymptomatic, wear masks in travel and are tested on entry.

“Those things, you know, will sift out 99.9% of the cases,” he said.

Members of the travel industry are also calling for a data-driven approach to the new variant.

The International Air Transport Association (IATA) says the new travel restrictions are “not a long-term solution” when it comes to managing coronavirus variants.

“Governments are responding to the risks of the new coronavirus variant in emergency mode causing fear among the traveling public,” IATA Director General Willie Walsh said in a statement. “As quickly as possible, we must use the experience of the last two years to move to a coordinated data-driven approach that finds safe alternatives to border closures and quarantine.”

The measures could backfire

South Africa should be praised for its detection and reporting of the Omicron variant, not face travel bans, Dr. Margaret Harris, spokesperson for the World Health Organization, told CNN’s Kate Bolduan on Monday on “At This Hour.”

“South Africa should get a gold medal for the quality of its science and the quality of its transparency,” Harris said when asked whether the effect of travel bans was that South Africa was being punished.

“We have not seen nearly enough of that, of transparency particularly, and indeed to then make South Africa feel that doing all the right things leads to a very bad outcome is not good.”

As well as being bad for South Africa, it is also bad for the rest of the world, she said. “Other countries will then feel, ‘why would we come out and say we’ve got this issue, we’ve got this problem?’ if they see this sort of consequence.”

Correction: A previous version of this story misstated the title for Salim Abdool Karim. He is the former co-chair of the South African Ministerial Advisory Committee on Covid-19.

CNN’s Jen Christensen, Jasmine Wright and Sharon Braithwaite contributed to this report.