Question & Answer

Does flying increase the risk of contracting or spreading the COVID-19 virus?

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  • The level of coronavirus (SARS-CoV-2) infection and local control measures in the country you are leaving or flying to may affect the level of risk. Airlines take precautions, such as making passengers wear masks, hand sanitizing, spacing available seats and screening for sick passengers, though procedures vary between airlines.
  • There are limited confirmed reports of infections linked to flights. Such reports come from a small number of independent studies (e.g. Murphy et al. 2020, Nguyen et al., 2020 and  Yang et al., 2020).
  • However, due to limited testing and contact tracing of passengers, the risk of infection is not certain. It is difficult to determine precisely when an infection occurred (e.g. before travel, at the airport, on the flight or elsewhere).
  • Of the studies that have looked specifically at the transmission of COVID-19 during air travel, there is not enough high-quality evidence to support the claim that COVID-19 is spread through air travel. There are few rigorous studies, and overall the evidence is inconclusive.
  • However, the absence of evidence is not evidence of absence and national and international guidelines advise caution when flying.
  • The Centers for Disease Control and Prevention (USA) advises that flying on an airplane increases the risk of contracting COVID-19, because air travel requires close contact with other people and with frequently touched surfaces. “Most viruses and other germs do not spread easily on flights because of how air circulates and is filtered on airplanes. However, social distancing is difficult on crowded flights, and you may have to sit near others (within 6 feet), sometimes for hours.” (CDC, Nov 2020)
  • The World Health Organization states that ‘Any situation in which people are in close proximity to one another for long periods of time increases the risk of transmission’.
  • The World Health Organization recommends that travellers who are sick should avoid travel, as should elderly people and those with chronic diseases or underlying health conditions. They recommend that those who do travel should ensure personal and hand hygiene, respiratory etiquette, maintaining physical distance of at least one metre from others and use of a mask as appropriate.
  • The guidance from the Irish Department of Foreign Affairs advises that Irish citizens continue to ‘avoid non-essential travel’ or in some cases, ‘do not travel’.”

Things to Remember

  • Beware of claims based on a single study. Ask if there are other studies that examine the same question and ideally, a careful summary of all the relevant studies.
  • Don’t confuse “no evidence” or “a lack of evidence” with “no difference” or “no effect”. And don’t be fooled if someone says there is “no difference” or “no effect”.
  • Beware of claims that are based on before and after comparisons and when people don’t say what a treatment was compared to. Remember: Ask what the treatment was compared to and whether it was a fair comparison.
  • Whenever possible, use up-to-date careful summaries (systematic reviews) of fair comparisons to inform decisions

Reviewers

  • Lead Researcher: Dr Nikita Burke, Evidence Synthesis Ireland, NUI Galway.
  • Reviewed by: Elaine Finucane, HRB-Trials Methodology Research Network, School of nursing and Midwifery, NUI Galway.
  • Evidence Advisor: Dr Maureen Kelly, College of Medicine, Nursing and Health Sciences NUI Galway
  • Evidence Advisor: Anne Daly, PPI Ignite, NUI Galway.
  • Journalist Advisor: Dr Claire O’Connell, Contributor, The Irish Times.