If you travel in a car with someone infected with the flu, your chance of getting sick is up to 99.9%, according to researchers.

The study compared 1989 and 2005 models of passenger cars and estimated the risk ranged from 59% to 99.9% for a 90-minute car trip when air was recirculated in newer, more air-tight vehicles.

The risk of getting sick travelling in a car is higher than travelling on a Boeing 747 for 17 hours with an infected person.