The U.S. Centers for Disease Control and Prevention (CDC) updated its guidelines this month to acknowledge that COVID-19 can sometimes be spread via airborne transmission.
However, the agency still maintains the virus is primarily spread via respiratory droplets between people within about six feet of each other.
So, what does this change in the guidelines mean for holiday travel? And how do you decide what is right for you and your family this holiday season?
The CDC says staying home is the option that guarantees the most safety, so if you want to travel or entertain visitors, you have to decide if it’s worth the risk. Infectious disease experts with The University of Texas Health Science Center at Houston (UTHealth) provide some advice to help guide your decisions.
Keep up the COVID-19 defenses you’re already practicing, and then some
By now, we all know the rules: wear a mask, physical distance, practice good hand hygiene, and don’t touch your face.
“COVID-19 likely has been able to be transmitted through the air the whole time – we just didn’t recognize it,” said Catherine Troisi, PhD, an infectious disease epidemiologist with UTHealth School of Public Health. “The question is how much does airborne spread account for transmission. Is it 5% or 95%? Early research shows it’s likely a pretty low percentage.”
If a disease is airborne, it means the droplets are smaller and can linger in the air longer and travel farther, Troisi said.
“Now the CDC is accounting for instances where it appears people were infected while staying in indoor settings for long periods of time, even while maintaining a six-foot distance,” said Michael Chang, MD, an infectious disease pediatrician with UT Physicians and assistant professor with McGovern Medical School at UTHealth. “So, COVID-19 does not seem to be airborne-spread as easily as measles, chicken pox, or tuberculosis, but it is possible for it to be transmitted through the air. This should cause some concern for high-risk scenarios like bars, eating inside a restaurant, and attending large gatherings indoors.”
“A six-foot distance is not enough if droplets are aerosol,” Troisi said. “Some studies suggest 15 feet, but do the best you can. Keep your distance and wear your mask – not one or the other.”
Consider the health of the travelers and COVID-19 spread
If any travelers are high-risk, or you are going to visit someone who is high-risk, carefully consider whether the trip is worth it – keep in mind, the CDC recommends staying home is the safest option.
You’ll also want to check if there is a high rate of community spread in either the area you are traveling from or your destination, as that raises the risk level of the trip.
“You might want to think twice about visiting a location with a high infection prevalence and where masks are not mandated,” Troisi said.
Quarantining 14 days before and after a trip or hosting visitors is recommended.
“If you are traveling or receiving guests and community spread in your area is high, I would recommend quarantining as best you can for 14 days before your visitors arrive and again after they leave,” Chang said.
Even if you do quarantine before and after, remember that you may get exposed during the travel time, so it doesn’t guarantee you won’t get the virus, Troisi said.
Are the friendly skies COVID-19 friendly?
While the CDC now says the virus can be airborne, the agency has not updated its travel guidelines, which suggests the guidelines in place are still working.
“There are a few reports of spread on airplanes, but overall we’re not seeing a ton of documented cases from airline travel,” Chang said. “The data shows transmission happening mostly on long overseas flights and among people sitting in close proximity. It seems that the air heating and filtration on flights is sufficient at killing germs, and assuming everyone is wearing masks, the biggest risk is the people sitting closest to you.”
If you do plan to fly, Chang and Troisi recommend the following to minimize exposure:
- Try to book a direct flight, instead of one with a layover.
- Choose an airline company that is requiring mask use, keeping middle seats open, and enforcing enhanced cleaning procedures.
- Use online or contactless check-in.
- Scope out the crowd at the gate. If it appears too crowded for your comfort level, consider changing your flight.
- Delay getting on the plane as long as possible.
- Sit near the back of the plane and avoid aisle seats, as those allow for more exposure to passengers and crew members walking through the aisle.
- Wipe down your seat and tray table with a sanitizing wipe and let it air dry before sitting down.
- Point the overhead air vent right at you, as the force of clean air will help keep out air that might contain infectious droplets.
- Don’t eat or drink, unless you use a straw under your mask to stay hydrated.
- Keep your mask on for the duration of the flight.
- Try not to go to the bathroom unless it’s an emergency.
- Bring plenty of hand sanitizer.
- Consider wearing a face shield over your mask for extra protection. Note, face shields are not effective unless you also wear a mask underneath.
Flying with kids
The CDC recommends kids age 2 and up wear a mask, but many parents report having trouble getting their youngsters to keep a mask on for long periods of time.
If your child is too young to wear a mask, or you don’t think they would wear it the entire flight, there are some additional factors you would need to consider when evaluating the risk of the trip.
“Children older than 1 and less than 10 seem to be at a lower risk for symptomatic or severe COVID-19,” Chang said. “So, the risk of the child becoming sick is relatively low, but does exist. On the other hand, children can spread the virus to adults, and apparent spread to an adult from an asymptomatic child has been reported. If the child becomes infected on the flight, he or she could spread it to other people at the destination. Again, there is a relatively small chance of this happening, but it is possible.”
On the road again
If your destination is within driving distance, a road trip in a car or recreational vehicle could be a safe option. As long as you’re traveling by car with household members or people you know have been careful during the pandemic, the CDC considers road trips low-risk.
“Theoretically car travel is safer than air travel, as you have more control over your environment,” Chang said. “However, there are still risks involved with road trips. Everywhere you stop along the way is a new opportunity for exposure to both people and surfaces, so be sure to choose places that aren’t crowded and that seem to maintain a high standard of cleanliness. It is also important to wash your hands or use hand sanitizer before eating and after touching any surfaces.”
Travel by bus and train are riskier due to the close proximity to people outside of your household and the lack of advanced air filtering that occurs on planes.
Research highlights on COVID-19 spread on airplanes:
Evacuation flight from Italy to South Korea:
- March 31
- 11 hours
- Strict infection control procedures – most passengers wore N95 masks except at mealtimes and when using the bathroom
- 299 had no symptoms during the flight
- Outcome after flight: 7 positive cases, including 1 symptomatic
- Symptomatic patient had used the bathroom without wearing a mask
- Conclusion: There was evidence of asymptomatic transmission of COVID-19 on an airplane. Masks, hand hygiene, and physical distancing can be effective at preventing transmission on flights.
Flight from London to Vietnam:
- Early March
- 10 hours
- Face masks were neither recommended nor widely used on airplanes in early March, in particular not among travelers from Europe.
- 217 passengers and crew members – only 1 symptomatic
- Outcome after flight: 16 passengers became infected, 12 of them were seated near the 1 symptomatic person in business class.
- Conclusion: Seating proximity was strongly associated with increased infection risk.
Flight from Israel to Germany:
- March 9
- 4 hours and 40 minutes
- No masks
- 102 passengers, including 24 members of a tourist group who had previous contact with a hotel manager who later tested positive
- Outcome after flight: 7 members of the tourist group tested positive and 4 of them were symptomatic during the flight. There were 2 cases of likely transmission to passengers outside the travel group. In both cases, the passenger was seated within two rows of someone considered an index case.
- Conclusion: Proximity to an infected passenger, not airflow on the plane, is the biggest risk of airplane travel.
Flight from Boston to Hong Kong:
- March 9 and 10
- 15 hours
- It’s unclear if masks were worn or not.
- 294 passengers – 2 of the passengers were symptomatic during the flight
- Outcome after flight: 4 people, including the 2 symptomatic passengers and 2 crew members, tested positive through reverse transcription PCR testing (genetic testing). All 4 were hospitalized. Contact tracing was used to identify one of the crew members. Note: not everyone was tested, so this is not a complete picture of what happened.
- Conclusion: Genetic sequencing suggests the passengers transmitted the virus to the crew members during the flight. To prevent transmission of the virus during travel, infection control measures must continue.
Other helpful guides from the CDC: