If you’ve spent most of the Covid-19 pandemic working from home, the idea of going back to the office might make you nervous — especially amid a surge in cases in some areas driven by the delta variant, which is highly contagious and may cause more severe illness.
Anecdotal reports of breakthrough cases among vaccinated people — which can obscure the key fact that vaccines available in the US are really effective against the delta variant — are fueling anxiety. And the Centers for Disease Control and Prevention’s new recommendation that vaccinated people go back to wearing masks indoors in areas with substantial or high transmission may add to uncertainty. Some employers that had planned to return to in-person work at the end of the summer, like Apple, are now delaying their reopenings at least until October because of the variant.
Saskia Popescu, an infectious disease epidemiologist at George Mason University, told me she believes companies such as Apple are right to delay reopening. (Some modeling suggests that infections due to delta will be decreasing by October.) “I really respect that they are doing that,” Popescu said. “Delta is more transmissible and only 50 percent of the US is fully vaccinated. And we know that people can work remotely and do it efficiently and effectively. I appreciate that they are prioritizing employee safety over this push to go back to the office.”
But some bosses are calling their US employees back to the office anyway. If you’re one of these employees, you may be wondering: How do I know if it’s safe to go back?
Before we dive in, there is one thing we all should be crystal clear about: The best way out of this pandemic is to put the vaccines in as many arms as possible. It’s safe to say that being vaccinated yourself and being in an environment where others are also vaccinated is the best way to lower your risk in a world where offices are opening back up and delta is raging.
Beyond that, you may have other questions: If people in the office are vaccinated, do they also need masks? What if there’s good ventilation? What exactly counts as good ventilation? How important is spraying down surfaces? Evaluating the relative importance of different risk mitigation strategies is no easy task.
Complicating matters is that we all calculate risk differently. Some see the excellent data on how much the vaccines protect against severe disease and hospitalization and are reassured enough after vaccination. Others, perhaps living with unvaccinated children or immunocompromised people, might lean toward the more cautious side.
Wherever you are on that spectrum, what follows should help you organize your thoughts and figure out the best course of action based on your own risk calculations.
Vaccinations, vaccinations, vaccinations
Vaccines are, simply put, the most effective way to keep the Covid-19 pandemic under control. No, they’re not perfect — but the ones in wide distribution in the US are highly effective, including against delta (though J&J’s one-dose vaccine may be less effective against that variant than the mRNA vaccines are).
According to the data scientists have so far, breakthrough infections are happening with greater frequency with delta than with the previous Covid-19 variants, though they are still uncommon (even if anecdotal reports might make them loom larger in the public consciousness). And when breakthroughs happen, they typically lead to no or mild symptoms. Severe disease and hospitalization among the vaccinated are exceedingly rare.
Given all that, it makes sense for employers to require proof of vaccination — and for the most part, they are legally allowed to do that.
“I think it’s very important. I think that’s the number one way to stay safe,” said Monica Gandhi, a physician and medical professor at the University of California San Francisco. “I’d encourage employers to do what we did in the state of California, which is to say we are requiring vaccination of our employees … or if not, then you have to be tested.”
New York followed suit, saying that city and state government employees must get vaccinated or face weekly testing. And the Biden administration announced on July 29 that every federal government employee will have to get vaccinated or will have to mask up on the job, physically distance from others, and get tested weekly or twice weekly.
Popescu said a vaccination requirement is crucial to ensure office safety. Muge Cevik, a virologist and physician at the University of St. Andrews in Scotland, agreed that it’s very important, but stopped short of saying it should be absolutely required. “Some people say, ‘No jab, no job.’ I don’t think that’s fair,” she said. “I think people should be able to show a negative test result or immunity certificate” (that is, proof that you’ve already had Covid-19 and are no longer infectious).
Ventilation is still key
If you and everyone else in your office are vaccinated, that’s already the biggest, most important battle won.
That said, if you’re looking to minimize risk further, look to your office’s ventilation. Gandhi emphasized that “in light of the delta variant, it is very important to have good ventilation even if your office requires vaccines,” adding that ventilation is that much more important if your office does not require vaccines.
Covid-19 travels through the air, so your office should have a plan in place for how it’s going to ventilate (which means regularly replacing indoor air with fresh outdoor air) or filter (which means cleaning the indoor air).
The most obvious way to ventilate, especially during the summer and early fall, is to keep windows open and keep doors open to outside hallways. Most office buildings have central HVAC systems, and a really good one will provide four to six air exchanges per hour — meaning that every 10 or 15 minutes, the indoor air is being replaced by fresh air from outside.
Not every building will be able to provide this. But there’s another alternative: filtering. If your office doesn’t have an adequate ventilation system in place, it should consider investing in a filter that can catch tiny particles in the air — ideally one with a MERV-13 designation or higher (the higher the MERV number, the better).
Don’t be shy about asking your employer about their ventilation and filtration systems. “I recommend asking how many air exchanges occur per hour and if they’re using any additional filtration like a MERV-13 or if they’ve put HEPA filters in place,” Popescu said.
Depending on the vaccination requirements in your office and your own risk assessment, you may also be considering getting a portable HEPA filter to place on or near your desk. Don’t bother with the filters that claim to kill viruses with ultraviolet or ionization; they’re unnecessary and sometimes ineffective, experts say. And bear in mind that although a HEPA can filter at least 99.97 percent of particles that are 0.3 microns in size, it’ll probably do a better job in a small conference room than in a big, open office space. In the latter case, Popescu said, “you having a small HEPA filter is helpful, but it’s not a risk eliminator.”
What about masks?
If your office doesn’t require vaccinations, then some people there may be unvaccinated. According to the CDC and the experts I consulted, that means everybody should be wearing a mask in regions with substantial or high transmission (which includes most US counties at this point).
“In a situation where an entire office is fully vaccinated, that’s a much safer situation to remove masks,” Popescu told me. But she added that with delta raging, there’s still a small chance of breakthrough infections. So she said we should be respectful of the fact that different people will make different personal decisions about masking based on their unique circumstances.
“I would encourage people to be mindful of community transmission and risk tolerance, so if they have vulnerable people at home and they want to wear a mask in that space, they feel comfortable doing so,” she said.
In terms of the community transmission part of that calculation, you may be wondering: How do I know what counts as a low community transmission rate, versus what counts as substantial enough to warrant more precautions? A recent CDC report spells this out: A substantial transmission rate is anything above 50 new cases per 100,000 people in the last seven days. (Note that 50 here is the cumulative total of new cases over seven days; it’s not the average daily number of cases.)
“What that means is, say over the last seven days you had 10 cases per 100,000 people a day — then you’ve got 70, so you are at that substantial rate,” Gandhi explained.
Another (potentially easier) metric to look at is your region’s test positivity rate: A rate of 8 percent or higher indicates substantial transmission, according to the CDC.
You can easily check your county’s transmission and test positivity rates on the CDC’s data tracker. Note that if one metric is high and the other is low, the CDC says “the higher of the two should be used for decision-making.”
One more thing to consider is spacing. Distancing from each other has been so drilled into our heads during the pandemic. But it’s somewhat less important in the office context than you think.
To be clear, the number of people in a room (as well as the size of the room) does affect the level of risk; fewer people near you means fewer people who could potentially be infected and pass on the infection to you.
“I think it’s somewhat important because we know from contact tracing studies that the closer you are to the infected person, the more likely you are to be infected,” Cevik said. However, she added that if employees are spending hours together in a workplace, proximity doesn’t matter as much. That’s because the virus travels, not just as large droplets, but also as tiny aerosols that can remain suspended in the air.
As a result of that finding, “distancing now seems like it’s the least important of the three Covid-19 mitigation strategies of masking, ventilation, and distancing,” Gandhi said, citing a study that found it didn’t make much difference when schools spaced out students by 6 feet versus 3 feet.
The end of hygiene theater
Let’s be clear: Nobody’s saying that we shouldn’t bother to wash our hands or that offices shouldn’t bother to disinfect shared surfaces. But the experts I spoke to told me that this is about as important now as it was in a pre-Covid-19 world — when offices should have been disinfecting to prevent the spread of things like norovirus and the common cold.
“That’s a helpful intervention strategy, but it’s not the main one. I view that as a regular office practice,” Popescu said.
We’ve learned that surface transmission is not a primary way that Covid-19 spreads, so we shouldn’t obsess over “hygiene theater” — especially if it distracts us from paying attention to the more important mitigation strategies listed above.
The same applies to physical barriers between workers. The experts were resoundingly clear on this one: Don’t bother. The virus’s ability to travel in aerosolized form means there’s pretty much no point.
“If you’re spending a long time in an office space, you will be breathing in and out the air,” Cevik said. A barrier is, obviously, “not going to stop that.”
Popescu added that the only time plexiglass barriers might be helpful is in scenarios when two people are briefly talking without masks on — when you’re buying something from a vendor, say — and the barrier provides a visual reminder to stay distant. But if you’re sitting amid your colleagues for hours at a stretch, is it worth putting up barriers? “I wouldn’t do that,” she said.
She’d rather offices consider requiring vaccines, invest resources in improving ventilation, and create a process for notifying employees if there’s been an exposure at work and encouraging people to stay home if ever they test positive or have symptoms.