We have been conditioned to think that medical capacity is the most important sector to support during a pandemic. After all, the problem is that a lot of people get sick, but there aren't enough beds, nurses, or supplies to treat them all. If we want to avoid dire outcomes, the thinking goes, we should increase the supply of medical care to cover the surge in demand and keep the medical system online at all costs. This would be a mistake.
It is tempting to think we have a good idea of what another pandemic would look like: staying home, wearing masks, and other such inconveniences. But by historical measures of lethality and infectiousness, COVID-19 was fairly mild. The next pandemic could be much worse. If critical workers stay home out of fear for their own safety, it won’t take long before essential services experience disruptions. Hospitals rely on functioning infrastructure in order to exist—if clean water, electricity, and food are not available, nobody will get treatment. As such, more attention should be paid to the essential services that undergird society as a whole. If we don't prioritize foundational infrastructure, we could face a catastrophe far worse than just an overloaded healthcare system. In order to robustly prevent collapse, countries must make an earnest attempt to answer the question of, "who are our most essential workers?"
All countries have limited supplies; if those supplies are sent to the wrong place, fundamental infrastructure will break. It is therefore crucial for governments to identify and prioritize those sectors of the workforce which keep essential services running. Resources should be used to buttress the foundations of society, not make everyone feel like they are wanted and loved. During COVID-19, the government's Cybersecurity and Infrastructure Security Agency (CISA) listed an enormous portion of the American workforce as essential, such as clergymen and school administrators. This is not a rigorous attempt at prioritization. In order to survive on a day-to-day basis, humans need food, water, and shelter—the rest is optional. 1 1 The distribution of food and water requires energy as a prerequisite. Beyond survival, if we want to maintain modern post-industrial living standards we must also ensure that society doesn’t lose access to physical and economic infrastructure (e.g. transportation and markets), and the supply of public goods such as education. Expand Footnote Collapse Footnote
The CISA report offers the following risk categorization matrix for workplaces to determine the safety of their staff:
Setting: Are workers indoors or outdoors?
Vaccination Status: Are employees vaccinated?
Proximity: How physically close are workers (and customers) to each other?
Type of contact: Do workers touch shared surfaces, common items, and other workers or customers?
Duration: How long does an average interaction last?
Number of different contacts: How many interactions occur daily?
Employee risk factors: Which workers face heightened risk due to their age or underlying medical conditions?
Capability to assess possible infection: Are there screening protocols that protect workers (and customers) from interactions with contagious people?
Cleaning: How frequently can the facility be sanitized and cleaned?
This matrix provides a helpful way to think about levels of risk within a workplace, but since it does not determine priority, it tells us little about how to distribute resources. Even more importantly, it doesn't tell us whether the bulk of the workforce should stay home in the first place. When allocating limited resources, the first step is to determine which sectors prevent society from collapsing. 2 2 To determine which sectors are critical, it is important to evaluate the probability and consequences of failure across a range of pandemic scenarios. In other words, an expected value calculation. Here’s one heuristic for thinking about the probability of failure: how likely is an important sector to fail at 20%, 50%, or 70% worker absenteeism across periods of 1 months, 3 months, or 6 months? This would likely depend on factors like level of automation, built in redundancies, maintenance requirements, failure modes etc. Expand Footnote Collapse Footnote The second step is determining which workers in those sectors are essential to provide the minimum level of services required to keep society running. If the government only has a limited quantity of masks, they should go to the most essential workers at a water treatment plant, not to entertainment professionals who can safely stay home. Creating a framework for thinking about questions of essentiality between and within sectors is critical for distributing limited resources.
Once the essential workers are determined, a top priority will be to keep them safe so that they show up to work. If a pandemic is as deadly as, say, the Black Death—which killed perhaps half of Europeans—it is safe to assume that most essential workers would prefer to stay home unless they can be reliably protected. One of the most reliable and robust ways of protecting workers is with Personal Protective Equipment (PPE). But not all PPE is made equal. Holding your t-shirt up to your face is less effective than a cloth mask, which in turn is less effective than an N95 mask. A physical barrier which walls off one’s mucus membranes from the outside world is ideal.
When we began our research at MIT, we sought to understand how masks failed during the recent pandemic and explore ways to achieve greater respiratory protection the next time around. Our initial hypothesis aligned with a common post-pandemic sentiment: we need higher-quality masks, which probably necessitates breakthroughs in material science. However, our research largely disproved this notion. The market already offers masks, called powered air-purifying respirators (PAPRs), which offer near-absolute protection from respiratory infection.
PAPRs will not make you fashionable, but they will reliably keep you alive. They are far more robust than N95s, which protect the wearer only if they form a tight seal around the user’s face. Mask fit is an underlooked aspect of PPE effectiveness, which is not just about the device’s raw filtration ability, but also how easy it is to properly wear the device. With most negative pressure respirators, like N95s, any gap which lets in unfiltered air raises infection risks. This is why healthcare workers typically undergo fit-testing—a meticulous procedure to ensure the mask's seal remains airtight under various conditions. But this is precisely what makes them ill-suited for pandemic use. A perfect seal can be hard to maintain under many work conditions, and coordinating fit-testing for all essential workers in the midst of a pandemic is impractical. 3 3 As acknowledged by public health officials at NIOSH and the CDC. Expand Footnote Collapse Footnote
Despite their odd appearance, PAPRs are also far more comfortable than most masks, since they actively pull in ambient air, rigorously filter it, and then deliver a steady flow of purified air to the wearer. This makes breathing easier since air is gently blown towards the wearer’s mouth. The fan also makes a perfectly airtight seal unnecessary, as air is not escaping into the mask through the gaps but being blown out. 4 4 The more gaps there are in the mask, the more power the fan will require in order to ensure that air doesn’t escape into it. Such power can be noisy. Expand Footnote Collapse Footnote This allows PAPRs to be worn comfortably for long durations. Additionally, since they are not forming a tight seal, wearers do not feel the need to scratch or inadvertently rub their eyes or nose. Unlike N95s, the positive pressure makes them compatible with more effective filters, such as HEPA filters, without increasing the difficulty of breathing. PAPRs are thus an effective defense against arbitrarily virulent and infectious pathogens.
That’s the good news—the technology that we need to defend against most pandemics is available today. We don’t need a massive R&D push, much less a Manhattan Project, to guard against civilizational collapse from pandemics. 5 5 Including human engineered pathogens which may be especially contagious or deadly. Expand Footnote Collapse Footnote And we know that they work in practice: Singapore’s medical staff used them throughout the pandemic. However, cost is a significant bottleneck preventing governments from being able to purchase sufficient quantities. A PAPR retails between $1,000-$1,800 whereas N95s are available for about a dollar apiece. 6 6 The price of a PAPR depends on battery life, comfort, ergonomics, etc. Expand Footnote Collapse Footnote That said, the superior protection and reusability of PAPRs makes them more competitively priced once adjusted for health outcomes.
There are two reasons why the government should begin to purchase PAPRs now. Firstly, we need to have a stockpile in case of another pandemic. Since the normal market for PAPRs is tiny (~2 million units sold globally every year), it will be hard to coordinate supply chains and manufacturing in an emergency. It is far easier to nip a pathogen in the bud before it becomes widespread, rather than attempting to address a full-blown pandemic. Secondly, purchasing PAPRs now will help drive down the price and spur further innovation through market forces. PAPRs are predominantly used in industrial settings with large quantities of air-borne particulates, but they can be optimized for dealing with pathogens instead, which should help reduce their cost. One startup claims to have successfully produced a PAPR intended for healthcare workers for $300, but there just isn't the demand to carry it to market. 7 7 A small group of large companies, including 3M and Honeywell, enjoy significant brand recognition and market share for PAPRs. This type of market structure—with low competition, high barriers to entry, and low incentive to innovate—may point to high margins and low economies of scale, which can be ameliorated by increased demand. Expand Footnote Collapse Footnote
There is no doubt that we need additional tools to safeguard nations against future pandemics. Even under the most optimistic estimates, the rapid deployment of an mRNA vaccine will take too long. 8 8 If we design an mRNA vaccine within 24 hours of sequencing the virus and find ourselves in the position of reaping the rewards of years of institutional reform to massively accelerate the vaccine approval process, it would take 100 days to start vaccinating high-risk immunocompromised individuals. Even if we’re able to hit the ground running with our peak daily vaccination rate of 3M doses a day (which took 3 months to ramp up to during Covid-19) it would take another 100 days to vaccinate the larger American public. These rosy estimates would require a cultural shift with different norms around bioethics and risk that are far from a reality. Expand Footnote Collapse Footnote And once we identify our most essential workers, we can do more than just provide them with PPE once a pandemic hits: we can also install preventative measures beforehand. For instance, workplaces could be outfitted with technology aimed at curbing the spread of potential infections year-round. These solutions include modifications to the built environment to improve ventilation and filtration, such as upgrading old HVAC systems or supplementing them with portable air purifiers equipped with HEPA filters. Another option is to implement disinfection systems that utilize ultraviolet light. Strengthening our infrastructure can also be achieved through improved Standard Operating Procedures (SOPs) and emergency-specific work protocols.
Any pandemic plan must have three strategic imperatives: to delay the outbreak from happening, detect it when it does happen, and defend against it after it has begun. PAPRs are incredibly useful once a pandemic is underway, but it’s far better to never need them at all. Delaying a pandemic involves lowering the annual risk from zoonotic spillover, lab accidents, and malicious actors. Early warning systems can also save the farm without invading people’s privacy. 9 9 One promising solution is monitoring city wastewater, or even better, wastewater from airplanes. See the Nucleic Acid Observatory’s work. Expand Footnote Collapse Footnote However, we must also prepare to defend ourselves against a highly virulent and infectious pathogen. Preventative measures are key, but PAPRs are our last line of defense. Their importance cannot be understated: when all else fails, essential workers wearing PAPRs will ensure the lights stay on.