Scientists have rapidly mobilized to study coronavirus and figure out the best ways of combating its spread. Unfortunately, the latest research finds that travel restrictions, such as the White House ban on inbound travel from Europe to the U.S., are not especially effective. Below are insights from papers published by Science magazine.
Travel bans are only modestly effective absent interventions to slow the rate of domestic transmission. Though the movement of infected individuals decreased dramatically after China’s travel restrictions, it only stalled the spread of the virus elsewhere by 2-3 weeks. Because the virus is so easily transmittable, the impact of new cases entering a given country is negligible.
The travel quarantine of Wuhan delayed the overall epidemic progression by only 3 to 5 days in Mainland China, but has a more marked effect at the international scale, where case importations were reduced by nearly 80% until mid February. Modeling results also indicate that sustained 90% travel restrictions to and from Mainland China only modestly affect the epidemic trajectory unless combined with a 50% or higher reduction of transmission in the community.
Airport screening is even less effective because it rarely intercepts infected travelers.
Research and recent experience shows screening of departing or arriving passengers will likely do very little to slow the spread of the virus as it’s exceedingly rare for screeners to intercept infected travelers. Historically, studies have shown that travelers infected with severe acute respiratory syndrome (SARS), Ebola, and the H1N1 pandemic influenza slipped through airport screening. And the attempt over several recent weeks by the United States to catch those infected with SARS-CoV-2, the virus that causes COVID-19, at airports has not kept the disease from sweeping through the country.