Travel

Guidelines for Air and Other Travel

Introduction

Flying in a pandemic is high-risk, avoid it unless necessary. The risk lies in the sharing space, bathrooms, the many transitions along the way, and unpredictability due to last minute changes.

This guideline is for those who HAVE TO fly and aims to minimize the risk of being infected during the flight. The goal is to help identify the transmission risks of in-flight air travel, to provide recommendations about the risks of flying during the COVID-19 pandemic, and to propose strategies that mitigate the transmission.

Transmission of SARS-CoV-2 during airplane travel is vastly influenced by four main factors:

1. Passenger occupancy relative to maximal capacity
2. Wearing PPE (high-quality mask; goggles, face shield), including mask removal (for meals, drinking, etc)
3. Air filtration
4. Additional precautions: testing, lavatories, disinfecting

The risk of in-flight transmission is challenging to quantify as there is limited published data specifically on the in-flight transmission of SARS-CoV-2. However, five well-documented flights have described mass transmission events and over 2000 flights had known COVID-19 cases on board (e.g. the Eurosurveillance communication, Murphy et al.: “The flight-associated attack rate was 9.8–17.8%. Spread to 46 non-flight cases occurred country wide. Asymptomatic/pre-symptomatic transmission in-flight from a point source is implicated by 99% homology across the virus genome in five cases traveling from three different continents.”).

In addition to the risks on the airplane, risks of transmission in all parts of the process must be considered. To minimize risk, streamline the itinerary. Think of the flight as a chain of segments. One flight consists of at least 5 segments: planning, traveling to the airport, checking in and boarding, flying, leaving the airport, and ground travel to destination. Additional segments can include connecting flights, prolonged stays in transit, even overnight stay—whether planned or due to unplanned delay of departure. Avoiding extra segments reduces risk. In the following we address each essential segment and additional ones.

In Travel Medicine, risk assessment includes estimating baseline risk to the traveler, recognizing factors that may modify that risk, considering the role of interventions to decrease that risk, and accounting for other travelers perception and tolerance to risk. So, since passengers may not have control over the degree of occupancy on flights, this guideline will focus first on the four factors mentioned above. However, should occupancy allow it, passengers are advised to leave middle seats (and rows, if possible) vacant to increase distance and reduce the probability of transmission. Sit as far from others as possible and in a checkered pattern to avoid crowding. Window seats are preferred.

PPE guidelines are best followed from the moment you leave the house until you arrive at your destination, and surely form the time you enter the airport, during boarding, and during deplaning.

Personal Protective Equipment (PPE)

Masks

1. Wear high-quality face masks or respirators (N95, KN95, KF94, FFP2 or elastomeric masks over the nose and mouth).
2. Make sure your mask fits tightly around the nose and mouth; adjust the nosepiece to fit snugly around the shape of your nose.
3. If possible, trim or shave facial hair, or use a brace or fitter to create a tight fit between your mask and and your face.
4. Only manipulate your mask with disinfected hands, and avoid touching the inside surface of your mask. Handle your mask by the earloops or straps.
5. Keep your mask on for the entire duration of the flight, if possible.
6. If necessary to remove your mask for eating or drinking, do so quickly and replace your mask at all times when not actively eating/drinking. Consider keeping your mask on during chewing. (a facial shield is recommended as it prevents direct air-flow in and out of your mouth, but make sure not to touch your face and mouth while eating).
7. If possible, avoid removing your mask when others are doing so. It is best to stagger meals and drinking to reduce transmission via aerosols across the aircraft. Inquire whether meals can be staggered or consider removing your mask only after others have replaced theirs.
8. Consider using a straw that you can fit under your mask when drinking instead of removing your mask. This can maintain a better level of protection. Some airlines no longer provide straws. It may be useful to bring your own straw.
9. Powered Air Purifying Respirator (PAPR) with very light HEPA purifiers (Aurora[1]) can also be used with a variety of high quality masks.

Goggles/glasses

1. COVID-19 is airborne, which means that the SARS-CoV-2 virus can enter the body through the nose and mouth as well as through the eyes. Wear goggles that form a seal with your skin or fit tightly, not allowing contact with the surrounding air. Models are available that fit over prescription eyeglasses.
2. If you do not have goggles or don’t tolerate them well, any glasses (prescription or not) provide some protection. It is better to wear glasses than to wear no eye protection, and well-fitting goggles provide superior protection than glasses, especially from lateral airflow which can enter the eyes through the side gaps between your glasses and your face. Slip on eyeshields for glasses without side protection may be used if fully sealed goggles are not worn. Wear eye protection throughout the flight, during boarding and exiting the plane, and while at the airport.

Face shields

1. Invest in a comfortable face shield, ideally one that covers your entire face, including the chin and jawline to regulate the direction of air flows.
2. The faceshield can be worn in addition to other PPE (including glasses or goggles) for added protection both for you and for nearby passengers. Keep your face shield on during eating and drinking.

Air filtration

1. Air quality aboard aircraft is very important. The cabin air is usually exchanged every 3 to 4 minutes in modern aircraft. Some airplanes use 100% fresh air, while others mix about 50% recirculated air with outside fresh air, which is free of microorganisms at cruising altitude. Recirculated air needs to go, not only through a prefilter that traps the largest particles, but also through high-efficiency particulate air (HEPA) filters before re-entering the passenger cabin. So, while many aircrafts are equipped with HEPA filtration systems, don’t hesitate to ask if the airplane is using 100% fresh air or HEPA filtered air.
2. Check that air ventilation from over your head is fully open, and keep it open.
3. The general airflow is from atop your head to the gratings near the floor. So avoid a prolonged period of low head position, i.e. when reaching for items stored under a chair or fallen to the floor.
4. However, considering proximity to other passengers, personal HEPA filters can add a level of protection by providing filtered air directly to your face. A hood over your head that extends over part or all of your face, or a face shield, with the air purifier blowing cleaned and oxygenated air under it would reduce the chance that air flows bring in viral particles.
5. Portable HEPA filters are available for purchase at a relatively low cost (for example [1]). These chargeable units can be placed between you and the passenger next to you, or on your lap or table with air flow aimed at your face. Some planes have electrical plugs allowing higher flow HEPA purifiers and extending their use for longer flights. Otherwise, it can be plugged into other electronics for recharging where necessary.
6. While masks, goggles and face shields considerably increase protection against airborne infection, most masks do not fit perfectly around the nose and mouth, leaving small gaps between the mask and your face. HEPA filters can help secure clean air around you, decreasing the probability of inhaling infectious aerosols.

Use of lavatory

1. If possible, avoid using the lavatory. If this cannot be achieved, wear your PPE and avoid using the lavatory for mask/PPE adjustments.
2. Limit what personal items you bring into the restroom and avoid hanging them up inside the cubicle.
3. Wipe the seat with an alcohol based sanitizing wipe, taking care to handle gently if the toilet is automatic as this can cause it to flush while doing so, and allow it to dry. Use a disposable seat cover if provided, or carry your own, or lay toilet paper on the seat. Women and girls may wish to use a portable device such as a SheWee which permits standing urination.
4. Close the seat lid before flushing to avoid toilet plume. If there is no lid, turn away from the toilet as quickly as possible. Sanitize your hands well.

Further considerations: Contact, testing, sanitizing, communicating

1. Minimize social contact well in advance of traveling and after arrival, if possible, to reduce the probability of contracting COVID-19 before leaving for your destination, and of transmitting to others at your destination.
2. Test using antigen rapid tests multiple times before and after traveling, e.g. daily for at least a week prior to traveling and upon arrival at your destination.
3. Sanitize your hands and surrounding surfaces while on board. Disinfect all the apparatus of your seat (especially the touch screen, seat belt buckle, hand rests).
4. When walking along aisles, avoid using other aisle seats’ tops as handles unless necessary to prevent a fall. They are frequently touched but less frequently disinfected, the soft and porous material also makes them hard to disinfect. Aisle seat passengers should also pay special attention to that part of their seat when disinfecting and for avoiding contact.
5. Use a new pair of disposable gloves when eating, discard it after the meal.
6. Avoid touching your face, rubbing your eyes, or touching surfaces unless necessary.
7. Inform the air attendant if you feel unwell.

Planning ahead

1. Arrange for accelerated security and boarding where possible, for example, sign up for TSA pre-check and/or Global Entry.
2. Plan all stages of the trip carefully. Write steps down and commit to memory as much as possible.
3. Don’t fly if you suffer from COVID-19 symptoms or have close contact with COVID-19 patients in the past two weeks.
4. Rule of thumb: minimize both the number of environment shifts one has to take, and the complexity of actions needed.
5. Make sure you understand the pandemic prevention protocols and laws in your destination, especially if it’s another country. Learn to read the basic signs if it’s another language.
6. Arrange for testing to satisfy arrival requirements.
7. Prepare for the potential quarantine period after landing.
8. Know the metric system of your destination if it’s different. 6 feet ≈ 2 meters, 98° F ≈ 36.7° C.
9. Choose direct flights over multi-legged connecting flights.
10. Choose flights with limits on the number of passengers so that there are unoccupied seats between passengers, or flights for which passenger density is low.
11. Choose seats that are as far away from others as possible.
12. Choose window seats over aisle ones. Passengers in window seats are farther away from other seated and walking passengers, because they are not surrounded by them, and have better separation of airflow from them. Aisle seated passengers have more contact with others and shared air.  In a study of norovirus transmission aboard an airplane, sitting in an aisle seat was found to be associated with contracting the illness. Experimental studies of aerosol dispersion suggest that due to the airflow in the cabin, there are two air circulation zones at the sides and one in the middle. The downward airflow near the sidewall suppresses aerosol dispersion and lateral air flow between passengers is greater in the center section of the plane where there is some upward mixing of air.
13. Choose business class or first class over economy class.
14. Choose airlines that state they use HEPA filters for air circulation or, even better, that use 100% external air for ventilation during the flight.
15. Book pick-up/cars/hotels of destination city beforehand, minimize the time you stay in unfamiliar environments.
16. Aim for early arrival at all stages, avoid waiting in unsafe environments. Delays or forced change of itinerary will drastically increase the risk. Prevention measures make the procedures longer than usual, plan accordingly.
17. Make fall-back plans, stick to the rule of thumb about minimizing environmental shifts.
18. Put on the protective gear before leaving your home (in this document, “your home” refers to the place you stay directly before departure for the airport). Avoid putting them on in the airport as it requires dressing/undressing in an unfamiliar and hyper-frequently-used environment.
19. Obtain protective gear in advance: Protective gear includes facial masks, goggles, face shield, Tyvek suit or coverall, disposable gloves, shoe covers (if no Tyvek suit), disposable seating pads (with distinct sides or use marker to identify sides), portable rechargeable HEPA purifier, or use new light Powered Air Purifying Respirator (PAPR) [Aurora[1]]. Familiarize yourself with the donning and doffing of them, avoid over-complicated ones.
20. Make sure the protective gear and other hygiene products are able to get onboard. Pay special attention to alcoholic ones.
21. Prepare a separate set of protective gear for connecting flights (which should be avoided). Prepare a spare set in case of unexpected transition or other emergencies.
22. Prepare a bag of necessary transit items. Opening and closing the bag can contaminate items in the bag so use a bag that opens and closes quickly and separate items into compartments or in an additional layer of disposable bag.
23. For longer flights, place items in carry-on bag in ziplock bags. Extra gloves, masks, etc should be included. That way, you won’t contaminate all the items in the bag when reaching for one item.
24. When preparing for onboard food, avoid those that elicit coughing, like powders, dry crackers.

Traveling to the airport

1. Relieve oneself before leaving the house.
2. Avoid public transport. Public transport exposes you to more potential infection sources, and often requires transitions that add to risk.
3. Driving yourself and leaving your car at the airport, being driven by someone who you live with or is trusted in their precautions, taxi or UBER are the recommended methods to get to the airport in order of increasing risk. For taxi or UBER use special precautions including open windows (allow to air out before getting in) and disinfecting contact points and seat area or use covering sheet (see below).
4. If using UBER, confirm with driver first that they wear masks.
5. Rental car for transit to the airport that can be picked up very close to your home is another option but is typically less preferred as it involves more procedures, which increase the chance of contact, it also requires parking as one additional environment shift. If taking this option, prepare gloves and alcohol wipes. Open doors and let air out before entering, clean the frequently used parts of the car before driving, including handles, window control, turn signal, steering, gear shift, as well as seat area. Open windows and turn on ventilation of the car during driving.

Checking in and boarding

1. Keep in mind that the likelihood of coming into contact with other passengers is high during boarding and deplaning. Infection transmission depends on exposure time, points of contact, as well as proximity and movement of passengers.
2. Check-in early enough not to be rushed (but don’t extend the time in the airport unnecessarily).
3. Stand or if necessary, sit as far as possible from others in a low use boarding area. Typically, boarding areas are less occupied, hence lower risk, than airport lounges.
4. Use a seat pad and dispose of it before boarding.
5. Keep social distance while in a line.
6. Wear a well-fitting facial mask correctly over your nose and mouth. High quality (N95 or similar) masks are much preferred. Whatever the mask, make sure to practice donning and doffing to minimize the interruptions in wearing the mask and to keep the mask in good condition while you are traveling. Avoid complicated and prolonged actions while checking-in, especially when there is queue.
7. If you are checking bags, put everything that’s not used during the flight in luggage and check them. Keep a minimal number of items when boarding. This cuts the time you need before you can be seated, and avoids the additional risk involved with overhead bins. However, it requires checking bags and retrieving them from checked luggage. If this can be avoided altogether, it may be preferable.
8. Recommended items to keep handy in your carry on bag include:
   1. Replacement masks
   2. Hand sanitizer (this will need to be visible during screening)
   3. Facial tissues
   4. Disinfectant alcohol wipes for surfaces
   5. Water bottle to fill following screening (or purchase water in the airport after screening)
   6. Chewing gum to help with ear air pressure changes
   7. Any necessary medications, including commonly used over-the-counter medications
9. Board the plane according to the airline’s guidance, avoid crowded queues.
10. Relieve oneself before leaving the house and at the airport before boarding especially if it is a relatively short flight. Frequently-visited confined spaces are the riskiest, avoid the plane lavatory as much as possible, and use less crowded airport lavatory (if the airport lavatory is crowded, use the airplane lavatory at the time of boarding).
11. Dispose all tissues, wipes etc. used during the waiting period before boarding.

Considerations for other types of transportation

Trains (and to a degree busses)

1. Where to be on the platform (while waiting): Keep at least a 6-foot distance between yourself and others. Trains produce considerable wind upon arrival and departure from the platform. This causes air to move quickly first away from then toward the moving train. Remain farther from the edge of the platform and (when and where possible) downwind. Wait for passengers to unboard before approaching.
2. Do not move far inward once on the train. Be seated in the least populated portion of the train and avoid sitting next to other passengers. Hold on to a single handle (preferably through a wipe) and avoid touching multiple surfaces. Or use gloves and discard them afterwards. Avoid exiting the train from a door through which others are boarding. If seated, wait for others to exit the train and do not join a crowd of passengers on their way to exit.
3. Wear a well-fitting, high-filtration mask (N95, N100, KN95, KF94, FFP2, elastomeric mask, etc). If you can tolerate it, wear well-fitted goggles without gaps around the eyes and nose bridge. If this is not feasible, any eye protection is preferable to none, consider wearing a face shield in addition to or instead of eyewear. Additional layers of protection lower your risk of transmission and infection.
4. Consider bringing and using a portable HEPA filter. Position it to allow a flux of clean air for you forming a safe airspace for yourself that serves as a barrier between yourself and others’ breaths.
5. Do not use hands to assist in entering and exiting the train/bus if possible, or use gloves and discard them afterwards.
6. If possible, keep windows open to allow fresh air to circulate.
7. Disinfect hands and luggage, especially the handles, often and as soon as you exit the train.
8. Avoid sitting or standing near high traffic areas of the train adjacent to exit doors, bathrooms, food or other services.
9. Reduce contact with others before and after travel. Ideally, reduce outings to essential trips (grocery shopping and other essentials), or avoid altogether if delivery services are available. Multiple rapid tests before and after a trip will help reduce the risk of COVID transmission to others during travel and at your destination.

Cars

1. Driving yourself, or being driven by someone who you live with, without other passengers minimizes the risk of transmission.
2. It’s best to avoid car shares, taxis, or carpooling.
3. For taxi or car share use special precautions including open windows (allow car to air out before getting in) and disinfecting contact points and seat area or use covering sheet.
4. If using car share, confirm with driver first that they wear masks.
5. A rental car that can be picked up very close to your home is another option but is typically less preferred as it involves more procedures which increase the chance of contact. If taking this option, check if you can rent a car that has not been used for a few days before your rental. Wear high quality mask. Prepare gloves and alcohol wipes. Open doors and let air out before entering, clean the frequently used parts of the car before driving, including handles, window control, turn signal, steering, gear shift, as well as seat area. Open windows and turn on ventilation of the car during driving.
6. If using carshares/cabs: avoid social contact beforehand—or limit it to a social “bubble” whose safety practices you are familiar with—and afterwards.
7. Testing frequently before and after a trip and avoiding travel if exposure is suspected or if you are experiencing symptoms is appropriate.
8. Wear PPE– a well fitting mask (N95, N100, KN95, KF94, FFP2, elastomeric mask, etc), eye protection or a face shield, and make sure in advance that others you will be sharing space with also wear masks.
9. Avoid touching surfaces, drinking, or eating while traveling.
10. Keep windows open whenever possible to allow air circulation (when stationary in a train station or in a car with others nearby, close windows).
11. Consider the use of portable HEPA filters.
12. Disinfect hands and luggage. If not necessary, avoid conversation.
13. For longer trips, avoid public restrooms, eating out, and overnight stays in hotels, as much as possible.