The U.S. banned journey from China early, however the late timing of different journey bans meant the coronavirus had different routes into the U.S. AP Photo/John Minchillo
The coronavirus was nonetheless a far-away drawback in Wuhan when U.S. President Donald Trump introduced a ban on journey from China in late January 2020. Six weeks later, because the coronavirus ravaged Italy, Trump closed journey from Europe.
These journey bans have been extremely controversial. Some folks argued that they have been pointless restrictions on journey. Others mentioned they got here too late. As New York’s COVID-19 case numbers shot upward, Gov. Andrew Cuomo mentioned the U.S. had “closed the entrance door with the China ban … however we left the again door vast open,” as a result of the virus had already unfold to different nations.
One huge query stays: Once the virus was within the U.S., how a lot affect did worldwide journey even have on COVID-19 circumstances and deaths?
As researchers with expertise finding out airways, we pulled collectively knowledge to start out answering that query. We in contrast COVID-19 circumstances and deaths in practically 1,000 U.S. counties towards the numbers of passengers arriving in every from two nations focused by the bans – China and Italy.
Our outcomes, launched as a preprint examine, counsel that vacationers coming from Italy drove the primary wave within the U.S. greater than these from China. They additionally level to 2 conclusions about journey bans:
First, if a authorities goes to impose a journey ban, it ought to act rapidly. The virus spreads quick.
Second, don’t impose slim journey bans that simply goal particular person nations. Because the virus spreads so rapidly, you must assume the virus has already unfold to different nations.
We are discussing our findings earlier than the paper has undergone peer evaluate as a result of the outcomes are necessary for selections being made now. On Jan. 25, 2021, nearly a 12 months after Trump’s ban on journey from China, the Biden administration issued new journey bans on nations which have rising numbers of latest fast-spreading variants of SARS-CoV-2.
Italy versus China
In our examine, we used knowledge on worldwide airline journey and U.S. county-level statistics on COVID-19 circumstances and deaths. We wished to seek out out: Did U.S. counties with extra arrivals from two preliminary COVID-19 scorching spots – Italy and China – expertise extra COVID-19 circumstances or deaths through the first U.S. wave of the pandemic?
Early journey pathways of the novel coronavirus, via March 2020.
Nextstrain, CC BY
There are a number of challenges in attempting to evaluate the connection between worldwide journey and COVID-19 outbreaks. Fewer folks may journey to cities which might be within the midst of a pandemic outbreak. The areas that entice many international vacationers may additionally have extra extreme COVID-19 outbreaks for different causes. For instance, locations attracting a number of international vacationers could have extra giant occasions reminiscent of conferences and sporting occasions.
We used knowledge on passengers arriving from non-COVID-19 scorching spots to assist management for these components. We additionally took into consideration different components that may have an effect on the virus’s unfold and affect, reminiscent of inhabitants measurement and density, use of public transportation, demographics, insurance policies and financial exercise.
We got here away with two key outcomes:
U.S. counties that obtained extra passengers from China in the beginning of the pandemic didn’t expertise greater COVID-19 an infection and fatality charges than different counties on common via May 2020; in actual fact, each outcomes have been decrease.
Counties that obtained extra passengers from Italy in the beginning of the pandemic skilled greater COVID-19 an infection and fatality charges. Specifically, an extra 100 passengers from Italy arriving in a given county through the fourth quarter of 2019 corresponded with a rise in each case and dying charges of about 5%.
Benefits of broader bans
Our preliminary outcomes counsel that vacationers coming from Italy drove the primary wave within the U.S. greater than these from China. Other researchers have linked the predominant pressure of virus in New York City early within the pandemic to Europe.
Based on our proof, the comparatively early ban on journey from China seems to have been efficient in lowering circumstances and deaths.
In late January 2020, when Trump shut down flights from China, the virus could haven’t but unfold broadly sufficient amongst vacationers from China to considerably contribute to the early wave of the pandemic within the U.S. Waiting till mid-March to impose a ban on journey from Europe, nevertheless, could have had lethal penalties.
The lesson: If a journey ban is warranted, time is of the essence.
Does that imply future bans will work?
Although our outcomes present robust proof that worldwide journey from Italy elevated the unfold of COVID-19 within the U.S. through the first wave of the pandemic, this occurred at a time when folks have been largely unaware of the virus and the risk that it posed.
Today, with each vacationers and policymakers conscious of the risk, it’s unsure what impact worldwide journey would have on the unfold of COVID-19 within the U.S. At the identical time, new, extra transmittable strains of the virus enhance the risk from worldwide journey. If the proof does warrant further journey restrictions, our analysis says to behave rapidly and assume broadly.
The authors don’t work for, seek the advice of, personal shares in or obtain funding from any firm or group that may profit from this text, and have disclosed no related affiliations past their tutorial appointment.
