It is finally starting to feel like the beginning of the end of the pandemic. Multiple vaccines are proving to be effective against the virus and are being distributed around the world—albeit painfully slowly in some places. This is good news even for those way down on the priority list for receiving the vaccine. The more people get vaccinated, the lower the risk of infection for the unvaccinated becomes. With so many anxious to get back to work, the question still remains: how much of the local population needs to be vaccinated in order for people to return to their offices safely?
The answer to this question, like most important questions, is complicated. The first step is to define what we mean by “safe.” As we have learned, everyone has a different threshold for the risk that they are willing to accept when it comes to contracting a potentially deadly disease. The problem is, even when the vaccine is fully distributed, that risk will not go to zero. “We know from other vaccines that 100 percent of the population will not get it,” said Dr. Michael Gao, physician and founder of Haven Diagnostics. “We have had a measles vaccine for almost seventy years and we still see outbreaks.” Right now about two percent of the American population is infected. Dr. Gao thinks that we will need to see case levels of under half of a percent, about where we were in August, before the majority of the population will start to consider it safe to return to their normal lives. “If we can sustain case levels lower than .2 percent then I think people will start understanding that their risk of infection is acceptable,” he said.
But how long will it take for the vaccinations to get us down to that level? Again, the answer here is complicated and depends a lot on what is happening locally. John Cordier is the co-founder and CEO of Epistemix, a company that helps companies model health risks for their workforce. He explains that, despite the amount of vaccines that have been administered, the risk of infection has a lot to do with the local preventative measures. “We have to factor many different inputs into our models before we can understand each workplaces’ individual risks,” Cordier said. “First we look at what is happening in the community. Is there a mask mandate, are the bars and restaurants open, are kids attending in-person school? Then we look at the specifics of the workplace. Is there proper social distancing, how often is it sanitized, are temperatures checked regularly?”
Cordier and his team then run epidemiological simulations to see how the risk of infection drops based on how many people in the community have been vaccinated. They recently created a model for a 2,500-person facility in Pittsburgh, Pennsylvania for a Fortune 500 company.
As you move up and to the right across the infection heatmap, you can see how more employees can safely return to this particular office as vaccination levels in the surrounding community increase. The white boxes depict capacity and vaccination combinations that resulted in zero infections at work, while the pink-to-red boxes indicate one or more infections, with dark red indicating five or more infections that occurred at work. For example, this Fortune 500 could safely bring back workers at full capacity when at least 60 percent of the local population has been vaccinated, but they could bring half their staff back to work once the surrounding community reaches vaccination levels of around 45 percent. The simulation is calibrated to local conditions and accounts for workplace size, contact patterns, realistic social dynamics, COVID-19 natural history, regional vaccination levels, company policies, and building design, as well as employee demographics such as age, race, sex, and household zip codes.
Some companies have already started bringing workers back in small numbers which, according to the Epistimex model, is prudent even with only a minority of the population vaccinated. When to scale up the return to work can also depend on the type of work and the type of workplace as well. “If we look at the two extremes of risk on one side you would have a call center and on the other a law office,” said Dr. Gao. Call centers employees are constantly talking, work in one big room and generally have large meetings for all employees. Lawyers, on the other hand, do much more ‘heads down’ work, have mostly private suites, and smaller meetings. “It is important to understand which end of the spectrum each of your teams is on,” he explained.
A big concern for many when returning to the office isn’t in the office itself but is in the shared spaces like hallways and elevators. While these are certainly places where the virus can be contracted, Dr. Gao thinks that they are not as bad as many people would expect, “risk of infection is correlated to the amount of time exposed so if people are only in the elevators or common areas for a few minutes then the risk does not go up that much.” Keeping occupancy down in elevators is certainly still paramount to a safe office environment but might not turn out to be as important as what is happening in the offices where workers will spend the vast majority of their day.
Bringing workers back to the office is a hard choice for any manager. There is so much liability for making what can often feel like a gut call. But new models can help make this touch decision much more data based, giving confidence to managers and bringing transparency to the workers affected. Eventually we will return to normal, for many of us the sooner the better. Now we can better understand how soon that will be thanks to the medical teams that developed the vaccines and the expert analysis from people like Mr. Cordier and Dr. Gao.