"This is our Covid year. Let’s accept it. It’s not like last year and it’s not, hopefully, going to be like next year....So if you really love the people that you have in your immediate family...think through this. And actually do them the greatest gift of all and that is distance yourself this year and don’t expose them."
- Michael Osterholm, Ph.D., MPH, Director University of Minnesota Center for Infectious Diseases Research and Policy
“All human wisdom is summed up in two words - wait and hope.”
- Alexandre Dumas
Although it is still early in the month, the COVID-19 records already set in December are staggering. The number of daily cases as well as the number of hospitalizations and deaths skyrocketed to unprecedented levels. There is, however, good news to report. On December 3rd the U.K. became the first nation to authorize use of a vaccine produced by Pfizer/BioNTech, and on December 8th the first “jabs” of the vaccine were administered to members of the general population in the U.K. It appears likely that the U.S. will soon follow suit. It was no small feat that this vaccine and the others currently on the launching pad were all developed in record time.
Nonetheless, as the COVID-19 pandemic rages on, it is clear that while we await herd (community) immunity—when about 70% of the population is vaccinated—human behavior needs to change dramatically to slow the pandemic. And irrespective of the approaching holidays, that needs to happen now. This Germ Gem post addresses one such behavior that has already been affected enormously by the pandemic but needs to be impacted further this holiday season—air travel.
The role of travel in emerging infections. COVID-19 is only the latest of more than 140 infectious diseases that emerged or reemerged in humans in the past 50 years (collectively dubbed “emerging infections”). In the case of all of these emerging infections as well as in earlier pandemics that threatened the very existence of Homo sapiens, like smallpox and the plague, infected humans (or animals) carried the offending pathogens around the world to populations that had little or no immunity.
Rats and fleas infested with the plague bacillus accompanied unsuspecting warriors, traders and explorers in their travels spreading this deadly disease from central Asia to Europe and thereby wiped out huge populations in the 14th century. And far more than guns or any other weapons, infectious agents (including smallpox virus, measles virus, and the plague bacillus) caused the massive population decline among Native Americans in the 16th century. Back then, the available modes of transportation (ships, horses and walking) limited the rapid spread of the offending pathogen. With the invention of the airplane in the 20th century, however, emerging infections took off.
During the last century, air travel has become more and more affordable and thereby accessible. In the pre-COVID-19 era, there were more than 100,000 flights each day, making it easy for travelers to carry SARS-CoV-2, the coronavirus that causes COVID-19, from one part of the world to another. We humans traveling by air have opened the floodgates thereby enabling this virus to disseminate throughout the world.
The risk of contracting SARS-CoV-2 from air travel. Many of the major airlines apparently have taken steps to minimize the risks associated with air travel. In a November 24th article in Medscape (“A Reality Check on COVID-19 Risks from Air Travel”), journalist Victoria Knight summarized the results of studies conducted by Harvard University (funded by Airlines for America, a trade organization that represents major North American airlines) and by the Department of Defense (funded by United Airlines) regarding the risk of infection by SARS-CoV-2 associated with flying. Both studies supported the view that once the airlines ramped-up enforcement of mask-wearing, spacing of passengers, and assuring effective air filtration systems, the risk of in-flight transmission of the virus was “below that of other routine activities during the pandemic, such as grocery shopping or eating out.”
Public health experts cited in the article questioned this finding. They said "comparing time on an airplane with time at the grocery store is apples and oranges” as “the duration of contact in both locales is very different.” In a plane, you are in a confined situation where you are accumulating exposure from the time you board the plane until the plane lands and you can de-board whereas grocery store visits are of relatively short duration, physical distancing can be maintained and, more important, one can leave at any time.
The report also pointed out that the studies only analyzed the risk aboard the aircraft and never considered the risks associated with other aspects of air travel. But the interactions that one has in getting to the airport, going through security lines and waiting for a plane to board are not risk-free. All of them have to be taken into account when contemplating any air travel.
That was then, this is now. Medscape published the above-cited article in anticipation of the Thanksgiving holiday, traditionally the busiest time for domestic air travel across the United States. At present, we are still learning about post-Thanksgiving COVID-19 surges across the country brought about not only by air travel but also by family gatherings. While those numbers have yet to come in, we nonetheless do know that in early December, COVID-19 cases in the U.S. surpassed 10 million. The Johns Hopkins Coronavirus Resource Center reported this grim milestone and also reported that the global total of COVID-19 cases is now above 50 million. And on December 2nd daily cases in the U.S. topped 200,000. These alarming numbers suggest that the risk-benefit analysis of air travel needs to be reevaluated.
Perhaps an example can help in your evaluation. If the community you live in has a COVID-19 infection rate of 10% (10 out of 100 people), you can assume that whatever plane you travel on would have the same infection rate as the community around you. And, if as you stood in line to board the plane, and the airline announced that 10 people on the flight had tested positive for COVID-19, would you still get on the flight? It does give one pause.
On December 4th, the Center of Disease Control and Prevention (CDC) issued its report “Summary of Guidance for Public Health Strategies to Address High Levels of Community Transmission of SARS-CoV-2 and Related Deaths.” According to the CDC, the “COVID-19 pandemic control requires a multipronged application of evidence-based strategies while improving health equity: universal face mask use, physical distancing, avoiding nonessential indoor spaces, increasing testing, prompt quarantine of exposed persons, safeguarding those at increased risk for severe illness or death, protecting essential workers, postponing travel, enhancing ventilation and hand hygiene, and achieving widespread COVID-19 vaccination coverage.” Obviously, achievement of “widespread COVID-19 vaccination coverage” is not imminent. So, what do we do in the meantime?
Certainly, we need to assess the risks to ourselves that we are willing to take. But more important, we need to factor in the risks we pose to others, especially our loved ones, by doing what we might want to do or seeing whom we might want to see during this holiday season. Michael Osterholm, an infectious disease colleague at the University of Minnesota, suggests that if we don’t stop “swapping air” with our neighbors, friends and colleagues, COVID-19 case numbers will continue to grow substantially. He also proposes that this is a time when showing one’s love for others is best demonstrated by not getting together physically.
I am a retired physician living in Minnesota. I dearly love and long to see my children and grandchildren whom I have not seen in a year. But they live on the West and East coasts, respectively. I am not willing to put them at risk merely because I have a burning desire to be with them to celebrate this holiday season. (Conversely, neither my children nor grandchildren want to put either my wife or me at risk; it would be devastating for them if they thought they exposed us to the virus.) So, I have made a decision: no flying for the foreseeable future. Instead, I will be staying at home and I suggest you do the same…wherever your home may be.
When can we fly again? Of course, nobody can predict for sure when we can fly safely again and swap air, as well as stories, with friends and family. As treatments of COVID-19 continue to improve, thereby reducing the death rate, and widespread vaccination ramps up, thus resulting in a sharp decline in the spread of the virus, some experts believe that by this coming summer social gatherings will again be common and largely safe. I agree. But in the meantime the seasonal tune with the opening line “There’s No Place Like Home for the Holidays” has taken on a whole new meaning for me.
