Editor's Note: (Dr. Tom Frieden, director of the CDC from 2009 to 2017, oversaw responses to the H1N1 influenza, Ebola and Zika epidemics. He is president and CEO of Resolve to Save Lives, an initiative of Vital Strategies, and senior fellow for global health at the Council on Foreign Relations.
Dr. Shama Cash-Goldwasser, an infectious disease physician and epidemiologist, is senior technical adviser on the Prevent Epidemics team at Resolve to Save Lives, an initiative of Vital Strategies.)
(CNN) Omicron is causing a tsunami, not a wave, of infections in the United States. We've learned a lot about this coronavirus variant since it was identified less than two months ago. We know that Omicron is highly transmissible and now accounts for nearly all new Covid cases, having pushed Delta into the background. Omicron causes far less severe disease than Delta, especially among people who are fully vaccinated and boosted. And it appears that the current spike in Covid-19 cases driven by Omicron may subside nearly as quickly as it rose.
But the news isn't as good as it may seem. Rapid increases in cases are leading to increases in hospitalizations and deaths, especially among the unvaccinated, and may continue to increase for several weeks, even after case numbers start to decline. The huge jump in cases is already stressing our health system past capacity, as sick people flood doctors' offices and hospitals that are understaffed because health workers are also falling ill from Covid-19 and unable to work.
Because Omicron causes less severe illness than Delta, some have been tempted to claim that it's no worse than a bad seasonal influenza. Although this was not accurate a year ago (earlier coronavirus variants were far more lethal than any influenza strain of the past 100 years), Omicron is comparable in severity to flu. But there are important caveats.
On an individual basis, for people who are vaccinated and boosted, Covid-19 caused by Omicron and the flu are similar in severity in many respects. For the vast majority of vaccinated people, Covid-19 is likely to cause symptoms no worse than a bad cold or the flu, or even be completely asymptomatic. Most will recover within a few days, although some will require hospitalization and some, sadly -- primarily the unvaccinated, the elderly, those who are severely immunocompromised or those with multiple underlying comorbidities -- will die.
As is true for Delta, those who are unvaccinated are at much higher risk of severe illness caused by Omicron than those who are vaccinated. The risk of death from Delta among the unvaccinated was at least 10 times greater than the risk of death among the vaccinated.
For Omicron, the risk of death is estimated to be 90% lower than the risk of death from Delta; perhaps around 0.1% (1 in 1,000) of those infected with Omicron will die. But if the risk of death for unvaccinated people is 10 times higher than the risk of death for vaccinated people, those who are unvaccinated face a greater risk of death from Omicron than they do from the flu, whereas those who are vaccinated have an extremely low risk of death from Omicron.
On a societal basis, however, for the next few weeks, Omicron is likely to be much worse than "just the flu." Omicron is astonishingly infectious -- perhaps, with the possible exceptions of measles and chickenpox, the most infectious disease there is. Today in America, as many as one in 10 people may have Omicron.
Think of it this way: Flu infects around 60 million people in the US over three or four months. Omicron will probably infect at least twice that number in just three or four weeks. That means there could be 10 times as many Omicron cases as flu cases in the worst week of the Omicron peak, and flu itself often strains hospitals at the peak of its season.
About a third of Americans age 5 and older haven't completed their primary vaccination series (two doses of the Pfizer or Moderna vaccines or the single-dose Johnson & Johnson vaccine). Only 40% of people eligible for a booster have received one. In some communities, particularly in Southern states and in the Rocky Mountain region, vaccination rates are far lower.
Large numbers of cases, particularly among unvaccinated people and others with severe illness, stress our health care system and put us all at risk -- including those unable to access care for non-Covid emergencies such as heart attacks and strokes.
Anyone who says they know what's coming after Omicron doesn't understand Covid-19. We don't know what's coming next. Omicron could be the last big wave of Covid-19 before it turns into a more manageable endemic disease. Or Delta could re-emerge as Omicron wanes. Or there might be yet another variant that is both extremely transmissible and highly virulent -- next month or in five years. We simply can't predict the future of Covid-19 or of the next infectious disease threat, which is why we must increase our ability to adapt and roll with the punches.
Even if you don't consider yourself at high risk, getting Covid-19 may wind up being more than a minor inconvenience. It's also not clear how much an Omicron infection protects you from getting Covid-19 again. Many non-severe infections don't cause strong immunity. Now is not the time to either give up or "let it rip." But that doesn't mean Covid-19 has to dominate our lives. We can make a big difference by taking simple actions to limit transmission, shield the most vulnerable from infection and protect health care.
That means vaccinating as many people as are willing; wearing masks in public and especially in crowded indoor settings; upgrading to more protective N95 masks where indicated by individual (older, immunosuppressed) or situational (crowded, indoors, unmasked people in a high-Covid-prevalence area) risk; increasing rapid testing; isolating from the most vulnerable contacts for a full 10 days to limit their risk; and ensuring universal availability of effective Covid treatments.
Everyone is so tired of the pandemic. But the virus is adapting, and the quicker we adapt, the less Covid-19 will dominate our lives. If we work together, we can minimize the impact of Omicron and be in better position to handle whatever Covid-19 or another health threat throws at us next.