Manage virus transmission risk like the TSA manages passenger risk

Why take a COVID-19 vaccine? The best reason is it contributes to population risk reduction.   

In spite of such a compelling reason, after the initial surge of COVID-19 vaccinations in early 2021, the nation’s vaccination rate has slowed considerably, with several states languishing, mired below 40 percent of their population fully vaccinated.    

One bright light is that nearly 80 percent of those over 65 years old have been fully vaccinated, which has had a significant impact on reducing hospitalizations and deaths in this population. 

The nation is also fast approaching full vaccination for 60 percent of those who are over 18 years old and one-half of the nation’s total population. These are remarkable achievements over the past seven months, but woefully inadequate to achieve a level of protection that suppresses local outbreaks and keeps people out of hospitals in vulnerable areas with both low natural immunity and vaccination rates.     

As the Delta variant spreads and imposes itself across the nation, areas with low vaccination rates will continue to be at risk for outbreaks. Given the legality of requiring vaccination, can airport security strategies be adapted to reduce population risk, effectively protecting those who are unwilling to protect themselves and others? 

To answer this question, airport security contributes to air system risk reduction, effectively making the air system safer for everyone who flies. A key component of airport security is risk-based strategies, which align risk, resources and benefits.   

Risk-based strategies are the underlying concept for PreCheck, the Transportation Security Administration (TSA) program that permits travelers who voluntarily undergo a background check to qualify for expedited physical screening at airports. Airport screening assumes that all travelers are of unknown risk unless they voluntarily subject themselves to the PreCheck background check process to gain known, reduced risk status.  

How can risk-based strategies be used to reduce the nation’s population risk against COVID-19? 

People vaccinated are at low risk for transmitting the virus and are highly protected against poor outcomes like hospitalization and death, while those not vaccinated are at an elevated risk for such events. Like airport security, assume everyone to be at high risk, equivalent to being unvaccinated, unless they provide evidence to the contrary, equivalent to being vaccinated. 

Asking people directly for their vaccination status can be problematic. However, places of employment are one venue to confirm this information, with commensurate risk reduction actions taken.   

The way to do it is not by asking people if they have been vaccinated, but rather, asking people to volunteer and validate their vaccination status. Those who do so are eligible for roles that expose them to more people and hence, in environments with higher virus transmission risk. Those unwilling to offer such information are assumed to be at higher risk of transmission and placed in less vulnerable virus transmission roles.      

For example, in service sector commercial jobs like those in food service, transportation and retail, employees who volunteer that they have been vaccinated can be placed in roles that have greater facetime with the public. In retail outlets, those who are vaccinated can be assigned to work on sales floors, while those unwilling to volunteer their vaccine status work behind the scenes in the stock room. 

At airport security checkpoints, Transportation Service Officers who volunteer that they have been vaccinated can be assigned roles at security checkpoints that place them in direct contact with travelers. Those unwilling to offer such information can serve in roles like checked baggage screening that involves fewer touchpoints with passengers. 

The same holds true with airline personnel. Assign those who volunteer that they have been vaccinated to roles that most directly interact with passengers, while those unwilling to offer such information can take on checked baggage loading and unloading tasks and similar roles with fewer people touchpoints. 

Many jobs offer a multitude of roles with varying levels of interactions with the public. Risk-based strategies serve to exploit such variations and offer a mechanism to reduce the risk of virus transmission while giving people the personal choice of whether to volunteer their vaccination status. The result of such an effort is reduced population risk, which is the goal of vaccination. 

Sheldon H. Jacobson, Ph.D, is a professor of Computer Science at the University of Illinois at Urbana-Champaign. He applies his expertise in data-driven risk-based decision-making to evaluate and inform public health policy. His research on risk-based security provided the foundational concepts that led to TSA PreCheck.