A study conducted by Delta, The Georgia Department of Health and Mayo Clinic shows that pre-flight testing for Covid-19 could decrease on board infections “to a level that is significantly below active community infection rates”.

The peer-reviewed study used real-world data from around 10,000 travellers using Delta’s Covid-tested flights between New York JFK, Atlanta and Rome Fiumicino, and found that the risk of exposure following a negative test 72 hours before a flight is less than 0.1 per cent.

An example given was where the average community infection rate was at 1.1 percent (about one in 100 people), but the infection rate on Covid-19 tested flights was just 0.05 per cent (five in 10,000 passengers).

Dr Henry Ting, Delta’s chief health officer, said that the findings confirmed previous simulation models of viral transmission on planes.

“We are going to live with Covid-19 variants for some time, said Dr Ting. “This real-world data – not simulation models – is what governments around the world can use as a blueprint for requiring vaccinations and testing instead of quarantines to re-open borders for international travel.”

“Air travel risk varies depending on case rates and vaccination rates at the origin and destination, masking and other factors. But the data collected from this study show that the routine use of a single molecular test within 72 hours before international travel for unvaccinated individuals significantly mitigates the risk of COVID-19 exposure and transmission during airline travel.”

“When you couple the extremely low infection rate on board a Covid-19-tested flight with the layers of protection on board including mandatory masking and hospital-grade air filtration, the risk of transmission is less than one in one million between the United States and the United Kingdom, for example.

“These numbers will improve further as vaccination rates increase and new cases decrease worldwide.”

delta.com