We have underestimated the force that is SARS-CoV-2 and its impact on global society since the beginning. Our miscalculation of everything from how the virus spreads to how much it can adapt and change has led to the loss of millions of lives worldwide, with infections and deaths still on the rise to this day. You think we would have learned our lesson by now—and yet in the face of increasingly dangerous variants, a rhetoric of relentless optimism undergirded by complacency and inaction continues to cloud our better judgment.

Last year, neither the first appearance of the virus in Wuhan in late 2019 nor the dire situation that capsized Italy in March and April 2020 constituted a wake up call. Only after the first waves of Covid-19 cases hit Europe and the United States hard did either population begin to take the pandemic more seriously. This year, once again, the catastrophic outbreaks that slammed through India this past spring didn’t seem to be a sufficient warning that worse was to come. Instead many countries, the US among them, began to systematically dismantle the web of protective measures they spent the better part of last year building. Until now.

From where we’re standing, we can see even the most successful pandemic response strategies have missed the mark in some critical way. Those who relied extensively on rigorous lockdowns and border controls are now struggling to stamp out major new reinfections, for example in Australia and China. In the United States, where our masks and mass vaccinations have been our primary defense, case counts are escalating in many regions, particularly where these public health interventions failed to gain much traction. How did we get here? By telling ourselves stories that were convenient truths until they proved false—in other words, mythologizing a virus when it needed rigorous, evidence-based demystifying. Below I unpack a number of such myths, explaining the difference between what we thought then and what we know now.

Myth #1: Covid-19 originated in a foreign country, so it will remain a foreign virus.

Infectious diseases neither recognize nor abide by geopolitical boundaries. The world stood by and did nothing as Covid-19 infections escalated in China, when we should have known full well that nothing would stop it from reaching our respective shores.

Myth #2: Closing borders will keep Covid-19 out.

Blunt border controls didn’t thwart the virus from entering and circulating in Europe, the United States, or—as we’re now seeing with the rise of more infectious variants—countries where they were enforced most stringently, like China and Australia. The highly contagious Delta variant has proven adept at penetrating even the most drastic containment protocols. Only in the small country of New Zealand, where government officials have combined dramatic limits on foreign travel with rigorous screening, contact tracing, and mandatory isolation of all travelers, has this strategy continued to reap significant rewards.

Myth #3: Covid-19 will be no worse than seasonal flu.

Initially it was thought that Covid-19 might come and go like the seasonal flu, killing thousands but affecting most only mildly. The number of documented deaths from Covid-19-related causes now exceeds four million; clearly this wish did not come true.

Myth #4: Covid-19 will disappear on its own.

Many predicted the virus would vanish in the summer of 2020 or 2021, either quietly becoming endemic or succumbing to warm climates. But both summers the pandemic only intensified, proving SARS-CoV-2 can withstand tropical and even scorching temperatures, as has been the case in Indonesia. The virus is also on the rise in the US despite one of the hottest summers on record.

Myth #5: Covid-19 isn’t transmitted by aerosols, only droplets.

It took more than a year of research, surveillance, and health communications for us to collectively grasp that SARS-CoV-2 is an airborne virus. Once expelled, virus particles linger in the air like cigarette smoke, retaining structural stability and infectivity for up to several hours. In some cases, transmission of the Delta variant has been documented to occur outdoors.

Myth #6: Covid-19 cannot be transmitted by asymptomatic carriers.

Public health authorities dismissed the possibility of asymptomatic transmission from the beginning, without good reason. The notion that only symptomatic carriers could spread infectious virus was one of the reasons many countries kept their guard down early on—only to discover months later that asymptomatic spread was not only possible, but likely the main mode of transmission for SARS-CoV-2. If the new variants are better at delaying immune detection than prior strains, as experts including myself suspect, their asymptomatic period could last longer.

Myth #7: The Covid-19 virus changes, but slowly.

The first major mutation researchers detected in the parent SARS-CoV-2 strain, called D614G, developed near universal prevalence as early as spring 2020. But at the time, despite warnings to the contrary, many believed the virus had a limited repertoire of potential changes. The rapid appearance of new variants has since disproved this. With each passing variant of concern we learn more about the tremendous capacity SARS-CoV-2 has for persistence and adaptation. These changes affect replication, incubation, stability, transmissibility, and more.

Myth #8: Covid-19 vaccines offer long-lasting protection against infection.

The natural history of coronaviruses is comparable enough to that of influenza viruses that we could have anticipated the mutability of SARS-CoV-2—as well as the transience of our immune defenses against it. The first generation of Covid-19 vaccines has done an exceptional job at preventing severe illness and death, but how long that protection will last remains a gap in our knowledge too large for comfort. Even the best vaccines we have on hand, the mRNA vaccines created by Moderna and Pfizer, don’t erect an impenetrable barrier between the body and the virus. Instead they trigger an immune response that teaches the body to recognize and neutralize the virus on sight. If the virus mutates beyond immune recognition, then the vaccine loses all or most of its potency, hence the recently popularized term “vaccine-busting variant.”

Myth #9: Individuals vaccinated against Covid-19 won’t fall ill or die.

Again, now that more than two billion people around the world have received at least one dose of a Covid-19 vaccine, hospitalizations and fatalities aren’t reaching the precipitous heights we saw in 2020. But both are still on the rise, not just in populations with low vaccination rates but due to breakthrough infections in those who are vaccinated. While these events remain rare, if immune protection wanes over time, presumably they will become more commonplace. Any authorized vaccine is better than no vaccine, but we must be realistic about how much protection they actually guarantee us, or leave ourselves unnecessarily vulnerable. The recent death of seven Belgian nursing home residents due to the as yet unnamed B.1.621 variant, despite being vaccinated with Pfizer’s two-shot regimen, is a warning that protection from the most serious consequence of Covid-19 infection may soon obtain mythical status.

Myth #10: No matter how infectious the Covid-19 virus becomes, children will be spared.

In the 18 months that SARS-CoV-2 has lived among us, it has been consistently reported that Covid-19, with rare exceptions, doesn’t put most children and teens at risk for severe illness or death. This was fortunately true of earlier strains, to which younger individuals were far less susceptible than the average adult. But it no longer appears to be the case with the Delta variant. A higher proportion of children and teens are contracting infections; pediatric hospitals are filling up that last year, were all but spared; and child deaths are surging in Indonesia, where the Delta variant has claimed the lives of more than 100 children a week in the past month. The more children infected, the more will transmit virus to adults.

Myth #11: Covid-19 will weaken over time to become harmless, like a cold virus.

While this remains a possible outcome in the long term, given the trajectory of recent variants towards higher infectivity and virulence, it is unlikely to come to fruition anytime soon.

Myth #12: We are helpless in the face of new variants of Covid-19.

There is one more myth I will do the duty of busting: that we must resign ourselves to a future in which Covid-19 continues to wreak havoc around us. If we level up our pandemic response based on everything we’ve learned about SARS-CoV-2, we can still alleviate further suffering and death. An intensive, multilayered strategy that combines broadly protective Covid-19 vaccines, prophylactic and therapeutic drugs, public health measures, and international cooperation—which I’m calling Multimodal Covid Control—would gives us the boost we need to outmaneuver the virus for the foreseeable future. Given what we know now, why wait?