We are aware of the specific incidents on the studied flights (London to Hanoi and a Boston to Hong Kong), as well as other flights where secondary transmission on board the flight has potentially occurred.

IATA references incidents of onboard transmission in its Medical Evidence for Possible Strategies (pdf) to help the industry in its efforts to keep flying safe.

There have been millions of flights since the start of the COVID-19 outbreak. And there are very few reported incidents where onboard transmission is suspected. We believe that the data is telling us that the risk of onboard transmission of the virus is low when compared with other public indoor environments, such as trains, buses, restaurants and workplaces.

There are published examples which indicate a much higher risk in these environments. Aircraft benefit from very high air exchange rates and HEPA filters which filter more than 99.99% of all particles including viruses.

Furthermore, the two flights studied took place in March and a lot has taken place since. Most notably, face masks and face coverings are now common practice during flights and other environments where social distancing is not possible. And in June, the ICAO “Take-off” guidelines for safe operations during the COVID-19 crisis was agreed and is being implemented by governments.

While the risk of transmission on an aircraft is low, passengers can take additional precautions to further lower the risk. Following guidance to wear a mask or face covering provides significant protection to all onboard.

Passengers are also encouraged to practice good hand hygiene – washing hands regularly with soap or an alcohol-based hand sanitizer, and avoiding touching the eyes, nose or mouth, especially after contact with commonly touched surfaces.

We continue to keep an open mind and a close watch on emerging data and medical literature.