If you want to fly on vacation in autumn, you probably no longer have to wear a mask on board to and from Germany. This change in the Corona measures for the fall is becoming apparent during parliamentary deliberations, as Derstern also reported. Of course, people can continue to wear a mask on board a plane voluntarily, but what does it mean for the risk of infection if this is no longer mandatory?

How great the risk of infection is on the plane depends on various factors: how well the air is filtered, which air filters are used, how high the number of cases is, how high the viral load of a corona-infected person is and how close it is to mine environment, says Dr. Bjorn Jensen. He is Senior Physician at the Clinic for Gastroenterology, Hepatology and Infectious Diseases at the University Hospital in Düsseldorf. The risk of infection on the plane or at the airport cannot therefore be expressed in exact percentages, since this depends on a large number of factors, the complexity of which can usually only be approximately recorded scientifically.

"It is somewhat of a fallacy that all passengers in an aircraft breathe the same air. The air systems filter the air: air is extracted from every seat, filtered and fresh air is introduced into the aircraft," says Prof. Johannes Knobloch. He is a microbiologist, infection epidemiologist and head of hospital hygiene at the University Hospital Hamburg-Eppendorf. The effect: the air does not spread throughout the entire aircraft, but only locally. For the transmission of the corona virus via aerosols from a corona-positive person, a virus fog, it means that it does not spread through the entire aircraft. "The infectious aerosols can only be transmitted in the immediate vicinity before the air is sucked out. This means that an infected, contagious person who is not wearing a mask must sit in the row in front of, behind or next to me so that I can get a virus fog with me can become infected with the coronavirus." At the airport, too, infection via aerosols is not so likely - even without a mask requirement. "Most of the time there are high ceilings and the rooms are cooled. The warm air we breathe rises and an accumulation of aerosols is unlikely."

However, the risk of infection via droplets is higher on the plane and at the airport if all travelers are no longer wearing a mask. "In queues, when boarding, boarding and alighting and at the security check, I have closer conversational contacts where infection via droplets is possible," says Knobloch.

But even if almost no one wears a mask at the airport or on the plane, it is still possible to protect yourself. "If an FFP2 mask is worn correctly and is really tight, I can protect myself very effectively against infection - even if no one else is wearing a mask." For the protection of others, mouth and nose protection is at least as good as an FFP2 mask, sometimes even better. Because poorly fitting FFP2 masks are problematic. Through the resulting gaps between the face and mask, the breathing air penetrates outwards in a jet and aerosols can be spread relatively widely, says Knobloch.

But consistency is important for good protection, explains Björn Jensen. He says: "If you want to protect yourself optimally against an infection, you should wear a well-fitting FFP2 mask for the entire flight. The mask must not be removed to eat, even these minutes can be enough to get infected if one infectious person is nearby and not wearing a mask." Because: "The omicron variants are very infectious and so I can get infected even with brief contact via aerosols or larger droplets. In addition, many Sars-CoV-2 infected people even get infected with mild or asymptomatic courses of their corona infection are not aware of what increases the risk of infection, since neither they nor those around them see a reason for special behavioral measures."

It is difficult to predict whether the elimination of the mask requirement on airplanes will lead to an increase in the number of cases. But a look back shows the following experience: "In the past we have seen that vacation trips from countries with a higher number of cases brought infections to Germany. You could see that at the end of the vacation. You supported the start of the next wave." However, a flight or a stay at the airport without a mask should not be considered the sole risk of infection, but always the entire holiday. There is also a risk of infection when visiting restaurants, an evening at the disco or other activities without a mask, says Björn Jensen.

Johannes Knobloch sees it similarly: "I wouldn't look at the flight in isolation either. Increased contacts on vacation and the behavior there can lead to more corona cases during the classic travel times." Such an increase in return travel times is also influenced by other effects: "If I know that I want to fly on vacation in the next week and feel some cold and hoarseness, I might avoid getting tested so as not to make the trip If I come back from vacation and have symptoms, I'll be more likely to get tested." From an epidemiological point of view, the expert thinks it makes sense for masks to continue to be worn for protection in all situations at the airport and on the plane in which conversations take place and many people come together closely.

This article first appeared on stern.de on May 14, 2022 and has been updated.