AP Picture/John Minchillo
The coronavirus was nonetheless a far-away downside 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 folks argued that they had 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 extensive 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 instances and deaths?
As researchers with expertise learning airways, we pulled collectively knowledge to start out answering that query. We in contrast COVID-19 instances 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, counsel two vital conclusions.
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 must assume the virus has already unfold to different international locations. Our outcomes counsel that banning journey from Italy earlier may have diminished the U.S. COVID-19 unfold.
We’re discussing our findings earlier than the paper has undergone peer overview as a result of the outcomes are vital for selections being made now. On Jan. 25, 2021, virtually a 12 months 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 instances and deaths. We needed to search out out: Did U.S. counties with extra arrivals from two preliminary COVID-19 sizzling spots – Italy and China – expertise extra COVID-19 instances or deaths throughout the first U.S. wave of the pandemic?
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There are a number of challenges in attempting to evaluate the connection between worldwide journey and COVID-19 outbreaks. Fewer folks would possibly journey to cities which are within the midst of a pandemic outbreak. The areas that entice many overseas vacationers may have extra extreme COVID-19 outbreaks for different causes. For instance, locations attracting a number of overseas vacationers might have extra massive occasions reminiscent of conferences and sporting occasions.
We used knowledge on passengers arriving from non-COVID-19 sizzling 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, reminiscent of inhabitants dimension 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 originally of the pandemic didn’t expertise larger COVID-19 an infection and fatality charges than different counties on common via Might 2020; in truth, each outcomes had been decrease.
Counties that obtained extra passengers from Italy originally 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 loss of life charges of about 5%.
Advantages 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. Different researchers have linked the predominant pressure of virus in New York Metropolis early within the pandemic to Europe.
Primarily based on our proof, the comparatively early ban on journey from China seems to have been efficient in lowering instances and deaths.
In late January 2020, when Trump shut down flights from China, the virus might haven’t but unfold broadly 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, nevertheless, might 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 robust 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 folks had been largely unaware of the virus and the menace that it posed.
At present, 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 improve the menace from worldwide journey. If the proof does warrant further 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 educational appointment.