The risk of transmitting COVID-19 during a flight is lower compared to encounters made while shopping for groceries or eating at a restaurant, according to a new study published by the School of Public Health at Harvard University.

Published on Oct. 27 by researchers at the Aviation Public Health Initiative  (APHI) - a project associated with Harvard - the report cites scientific data demonstrating the low risk of transmission of SARS-COV-2 on board an aircraft.

Researchers believe that by taking advantage of technology and modifying certain behaviours, near-normal air activity is possible, while mitigating the risk of transmission.

Several levels of risk mitigation

According to the analysis, it is primarily through the ventilation of the air on board the aircraft that the possibility of exposure to COVID-19 is lower than that of other familiar environments, such as a grocery store or a restaurant interior.

Indeed, the frequent renewal of the air and its purification by a high-efficiency HEPA filter block the way to more than 99 per cent of the particles that may contain the virus.

In addition to filtering the air on board the aircraft, other measures act in synergy, such as ...

• universal use of masks by passengers and crew members throughout the journey;
• distancing protocols and strong ventilation during embarkation and disembarkation;
• disinfection of high-contact surfaces on board aircraft to remove contamination;
• certificates showing that passengers do not have symptoms related to COVID-19 and that they agree to respect the policy on line masks.

Returning to "some level" of normal 

"Our team found that, together with their high-performing ventilation systems, the actions that the airlines put in place - including mandatory use of face masks - significantly reduce risks of viral transmission aboard an airplane,” said Leonard Marcus, Co-Director of APHI. “With comprehensive adherence to these preventive measures by airlines and passengers, air travel, along with other sectors of society, can responsibly return to some level of normal activity as we await development of an effective vaccine.”

Ground recommendations

After establishing that the risk of contracting COVID-19 from airplanes is low, APHI researchers recommend that airlines acquire additional ventilation systems on the ground - in accordance with ICAO and manufacturer guidelines aircraft - to ensure that proper ventilation is maintained throughout embarkation and disembarkation procedures.

They also recommend that airlines continue to rigorously enforce behavioural guidelines regarding mask wearing and social distancing during boarding and disembarking.

Recommendations to passengers

APHI researchers are also questioning passengers.

They are recommended to maintain social distancing during embarkation and disembarkation, maintain hand hygiene and provide personal health certificates.

But first and foremost, APHI researchers urge passengers to wear the mask at all times - "except for very short periods of time to eat or drink."

About the mask

Findings about the wearing of a mask is neither new nor surprising. 

In fact, before producing its report on the risks of transmission of COVID-19 during a flight, the Harvard University School of Public Health had produced a comprehensive report on the wearing of masks on airplanes. 

(A very favourable report for the mask, it goes without saying!)

“The mask is part of a comprehensive series of measures to reduce the transmission of COVID-19 in airplanes. Passengers and employees of airports and airlines should be required to wear a mask during all stages of air travel, including at the airport, boarding, during the flight and disembarking," the report said. 

It was explained that wearing a mask is essential during all stages of the journey "since it reduces the emission of infectious particles into the environment."

“Reducing transmission at the source of infection (controlling the source) adds an important layer to preventing COVID-19 during air travel," it said. 

It was argued that since there is no cure or vaccine yet, non-pharmaceutical interventions like wearing a mask is one of the most pragmatic and effective methods of containing the spread of SARS-CoV-2.

"By taking this simple gesture, we are making a huge contribution to the safety of everyone," the report concluded.