Late last year, I participated in an exercise meant to play out what might happen if the world was presented with a new disease spreading quickly, with no warning.

The exercise revolved around a number of simulated emergency meetings of the World Health Organization advisory board, called in response to a very serious new pandemic — a risk that the W.H.O. refers to as “Disease X.”

Among the exercise participants were highly experienced current and past health ministers and senior public health officials from nine countries. The urgent events required them to make hard policy decisions quickly, with little information. Each decision had huge consequences for society and for the course of the pandemic. This was how it was in the early days of Covid. It’s also how it will be in other pandemics.

Some of the smartest and most experienced international public health leaders had differing, sometimes opposing views on many fundamental questions about the response. Should they shut down travel in the earliest days? Should they close schools in the first affected countries? If a future pandemic has a much higher case fatality rate than Covid or if it severely affected children, should countries take different, stronger, faster measures to contain it? Top experts don’t yet agree.

These will be terribly hard decisions for leaders to make. And that’s why it’s essential to anticipate and be ready for them in advance, reaching broad consensus where it’s achievable.

During the peak of the Omicron wave in January 2022, U.S. congressional leaders across the political spectrum were frustrated by the need to transform the country’s pandemic response. “We can never let this happen again,” was a frequent refrain.

But a year later, and three years after Covid was declared a pandemic, that collective resolve is diminished. The promise to prepare for pandemics in fundamentally new, far more ambitious ways has rapidly faded.

As horrible as Covid has been — it remains one of the leading causes of death in the United States — it is not the worst-case scenario. There are viruses with case fatality rates twice, 10 times or even greater than that of Covid, such as H5N1 influenza (bird flu), Nipah and Ebola. Fortunately, those viruses have not developed the capacity for efficient human-to-human respiratory spread. A concern is whether a new viral strain with higher case fatality will also develop the capacity for rapid spread among people. There is growing global concern over H5N1’s spread in animals — a development that governments must track and prepare for, and which all the more should broadly spur vigorous new pandemic preparedness efforts.

The world needs to be prepared for the next Disease X, something capable of causing global catastrophic risks. Here’s what it would take to collect all we learned from Covid and to transform our preparedness.

We need to get vaccines in arms much faster.
A number of countries call this commitment the 100-day mission — referring to the number of days it should take to develop a safe, effective vaccine after the sequencing of a novel pandemic virus. This would require serious investment from governments and close partnership with private sector vaccine manufacturing companies to establish much faster processes in research and development, clinical trials, regulatory review and more. It would require more investment in technologies such as mRNA that could be used for a range of Disease X threats. Right now, a large majority of government funding to help develop vaccines and medicines for pandemics is for existing, known pathogens, as opposed to preparing for future unknowns.

We need to make it much easier to develop and distribute tests.
Until diagnostic tests are widely available, leaders and the public will be flying in the dark in a future pandemic. We now know that we need contracts to exist between the federal government and the diagnostic industry that can be enacted quickly, because we don’t have time to start complex negotiations in a crisis. ‌

The Food and Drug Administration‌ needs a‌ clear and established path for rapidly reviewing new tests‌ during a crisis‌. The Centers for Disease Control and Prevention must be ready to provide immediate diagnostic clinical guidance‌‌, and health insurers and the Centers for Medicare and Medicaid Services need to be ready to provide quick and full coverage ‌for testing. Pharmacies, doctors’ offices and community centers should be positioned to dispense tests swiftly.

Imagine if in the first weeks of Covid ‌‌everyone could have easily gotten a free test at one of thousands of locations‌‌. ‌ That should be the expectation for the future.

We need a stronger stockpile of high-quality protective gear.
Our national supply of personal protective equipment, or P.P.E., was far too small ‌in the first months of Covid, especially when it came to masks. We need a far stronger and more resilient approach‌‌. ‌The U.S. supply chain is still quite vulnerable to disruption because we rely on so many single-use products that have components from around the world, which many countries will be seeking at the same time in a‌‌ pandemic. ‌

We ‌must be in a position in which health care workers and all essential workers can obtain very high-quality masks quickly. This means shifting at least a substantial portion of our national high-filtration-mask supply away from disposable single-use ones to reusable respirators that can be worn repeatedly‌‌ and safely.

We need to seriously change our approach to indoor air quality.
Just as we ‌expect‌‌ clean water from our spigots, we should have cleaner air moving through our buildings. Better filters, more outdoor air intake and new technologies to diminish pathogen burden should all be part of the plan – these things are key for future pandemics and for ‌lessening the toll of viruses overall. The Biden administration made substantial funding available for schools to increase ventilation, but many schools have not made these investments. The administration also began an effort to improve indoor air in buildings across the country, but most of the implementation of that plan‌ depends on local decision makers‌‌, building owners and operators, and better building codes.

We need stronger research oversight and lab safety.
It is still not clear what caused the Covid pandemic, and resolving that uncertainty would require new information and data. But even without knowing‌‌ what the proximal cause of Covid was, we should resolve nationally — and internationally ‌‌ — to operate labs with lethal and contagious viruses in the safest possible ways.

We need strong government oversight of that kind of work, with a framework that balances proposed benefits with major risks. A White House and National Institutes of Health review of these policies is underway now, and there are many important changes that if adopted would make U.S. policy and practice much safer and more effective on these issues.

These efforts are part of the larger set of actions and programs needed to prevent accidental or deliberate events from starting major epidemics and pandemics. That work should include requirements for monitoring or preventing the laboratory synthesis of deadly or extinct viruses; a strong national capacity to attribute a novel pathogen to its origin; commitment to support the Biological Weapons Convention, the international treaty that bans biological and toxin weapons; and vigorous scrutiny and oversight of the practice of extracting from remote ecosystems viruses ‌‌that may have pandemic potential‌‌ and have never been introduced to people or studied in a lab.

The C.D.C. needs a reset.
The C.D.C. has essential national pandemic preparedness and response responsibilities ‌‌as the nation’s top national public health agency. ‌‌But the pandemic revealed many of its challenges, including early testing mishaps, complicated public guidance and an inability to collect some key data that national leaders and the public needed. The agency needs new authorities to gather data quickly, new abilities to contract, retain and recruit talent, and new capacity to deploy people and funding to state and local public health organizations around the country that will need that assistance. ‌

The C.D.C. needs to operate rapidly in crisis, both in ‌the United States and internationally. Currently, its budget is broken into about 160 programs that aren’t allowed to be changed during pandemics ‌‌ — this must change. Some changes are in the C.D.C.’s control; others will require legislative solutions (‌like giving it more authority and funding‌).

These are not the only efforts needed — we also need stronger local public health capacity, stronger support to community organizations doing on-the-ground response work and more — but they are a critical start. And there are upcoming opportunities to act on them.

The Biden administration’s budget request asks for funding for pandemic preparedness, and Congress should embrace it. Congress also has the opportunity to reauthorize the Pandemic and All-Hazards Preparedness Act this year, and it could bolster, among many key capacities, the Administration for Strategic Preparedness and Response in its work to develop and distribute vaccines and to strengthen the supply chain.

Covid brought out incredible resolve, scientific ingenuity, individual and community perseverance and innovation. But even with that, millions of people died, many millions more were sickened, and societies were terribly set back in the United States and around the world. We are likely to face similar or worse pandemic threats in the future. We need to use the time we have now to make big preparedness changes to protect us from challenges that could arise again without warning.