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 Picture/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 had been extremely controversial. Some individuals argued that they had been pointless restrictions on journey. Others stated they got here too late. As New York’s COVID-19 case numbers shot upward, Gov. Andrew Cuomo stated 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 international locations.
One massive query stays: As soon as the virus was within the U.S., how a lot impression did worldwide journey even have on COVID-19 circumstances and deaths?
As researchers with expertise learning 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 in opposition to the numbers of passengers arriving in every from two international locations focused by the bans – China and Italy.
Our outcomes, launched as a preprint examine, recommend that vacationers coming from Italy drove the primary wave within the U.S. greater than these from China. In addition they 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 slender journey bans that simply goal particular person international locations. As a result of the virus spreads so rapidly, you need to assume the virus has already unfold to different international locations.
We’re discussing our findings earlier than the paper has undergone peer evaluation as a result of the outcomes are essential for choices being made now. On Jan. 25, 2021, virtually a yr after Trump’s ban on journey from China, the Biden administration issued new journey bans on international locations 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 needed to search 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 throughout the first U.S. wave of the pandemic?
Early journey pathways of the novel coronavirus, by way of March 2020.
Nextstrain, CC BY
There are a number of challenges in making an attempt to evaluate the connection between worldwide journey and COVID-19 outbreaks. Fewer individuals may journey to cities which can be within the midst of a pandemic outbreak. The areas that appeal to many overseas vacationers may have extra extreme COVID-19 outbreaks for different causes. For instance, locations attracting a whole lot of overseas vacationers could have extra massive occasions resembling 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 under consideration different components that may have an effect on the virus’s unfold and impression, resembling 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 acquired extra passengers from China in the beginning of the pandemic didn’t expertise larger COVID-19 an infection and fatality charges than different counties on common by way of Could 2020; the truth is, each outcomes had been decrease.
Counties that acquired extra passengers from Italy in the beginning of the pandemic skilled larger COVID-19 an infection and fatality charges. Particularly, a further 100 passengers from Italy arriving in a given county throughout the fourth quarter of 2019 corresponded with a rise in each case and demise charges of about 5%.
Advantages of broader bans
Our preliminary outcomes recommend that vacationers coming from Italy drove the primary wave within the U.S. greater than these from China. Different researchers have linked the predominant pressure of virus in New York Metropolis early within the pandemic to Europe.
Based mostly on our proof, the comparatively early ban on journey from China seems to have been efficient in decreasing circumstances and deaths.
In late January 2020, when Trump shut down flights from China, the virus could haven’t but unfold extensively sufficient amongst vacationers from China to considerably contribute to the early wave of the pandemic within the U.S. Ready till mid-March to impose a ban on journey from Europe, nonetheless, 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?
Though our outcomes present sturdy proof that worldwide journey from Italy elevated the unfold of COVID-19 within the U.S. throughout the first wave of the pandemic, this occurred at a time when individuals had been largely unaware of the virus and the menace that it posed.
At this time, with each vacationers and policymakers conscious of the menace, it’s unsure what impact worldwide journey would have on the unfold of COVID-19 within the U.S. On the identical time, new, extra transmittable strains of the virus enhance the menace from worldwide journey. If the proof does warrant extra journey restrictions, our analysis says to behave rapidly and suppose 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.
