Why U.S. Failed to Control Delta and Omicron, Now Dominant Variant

The Omicron variant is now dominant in the United States, accounting for 73.2 percent of new cases according to the Centers for Disease Control and Prevention. Its rise to dominance has been rapid. Omicron was first confirmed in the U.S. on December 1 in a traveler who had returned from South Africa on November 22. It's not clear exactly when the variant first arrived in the country—the CDC has reported symptoms as early as November 15 and it may have been present in the U.S. before then—but the data available so far suggests that Omicron is a highly transmissible variant.

Read more

• Omicron Became Dominant Variant in U.S. Faster Than Delta, CDC Data Shows
• Biden Admin Makes COVID Tests Free for All After Previously Dismissing Idea
• Biden's Original COVID Plan Falls Short on Testing, Mask Mandates

This was also the case with Delta, the variant that accounted for the overwhelming majority of new U.S. COVID cases in recent months until the rise of Omicron. Both strains quickly became dominant in certain countries they arrived in. Stephen Morse, professor of epidemiology at the Columbia University Medical Center and director of the Infectious Disease Epidemiology Certificate Program, explained why. "I think essentially the entire world failed to contain Delta," he told Newsweek. "Delta, with its unexpectedly high transmissibility, was able to take advantage of the holes in our surveillance and viral control measures. Even excellent surveillance would have difficulty keeping up with a virus that spread as quickly as the Delta variant, or Omicron. "As has happened throughout the pandemic, by the time the virus is identified it has already spread beyond its suspected origin." Joshua Salomon, a professor of health policy at Stanford University School of Medicine, thinks the U.S. was too slow to respond to Delta and its strategy was too weak when it did. "Ultimately, this translated into relatively anemic and confusing messaging and policy when we should have been preparing more proactively and then responding more aggressively to the Delta surge," he said. One parallel between Delta and Omicron is a reliance on vaccines rather than other measures to control the spread of the virus, according to Salomon. He said the Delta response had relied "almost exclusively" on vaccination and the White House had "largely doubled down" on a vaccine-centric approach to Omicron with a focus on boosters. "It seems to me very unlikely that we will be able to contain a large Omicron surge with only vaccinations, including boosters. But so far the White House has largely left any more aggressive actions and policies around masking and testing, for example, to state and local health officials. So, we are seeing the same sort of patchwork response to Omicron—led by some jurisdictions and shunned by others—that has characterized much of the U.S. experience over the entire pandemic." Evidence increasingly shows that booster shots may provide a marked increase in protection against the Omicron variant, compared to a primary course of one or two COVID vaccines. Earlier this month Pfizer said a third dose of its vaccine increased neutralizing activity against Omicron by 25-fold compared to two doses. U.S. surveillance and testing capabilities are also a factor. The Biden administration is to mail 500 million free at-home rapid COVID tests to U.S. residents starting next month—a policy reversal after the idea appeared to be dismissed by Jen Psaki, the White House press secretary, who asked a news reporter: "Should we just send one to every American? What happens if every American has one test? How much does that cost, and what happens after that?" Newsweek has contacted Psaki for comment. Yonatan Grad, associate professor of immunology and infectious diseases at Harvard T.H. Chan School of Public Health, told Newsweek that lack of access to rapid testing was "another major problem" since fast tests can help reduce the risks associated with social gatherings. However, Jason Roy, professor of biostatistics and chair of the Department of Biostatistics and Epidemiology at Rutgers School of Public Health, has praised progress in this area. He told Newsweek: "Many epidemiologists from around the world, including myself, have been very concerned about the level of surveillance at the molecular level for the United States. And we're happy that the Biden administration took that very seriously, and started to beef up the resources starting this past January, and that's continuing." Lots of questions remain about Omicron, such as the extent to which it evades vaccines and how ill it makes people. More data will emerge in the coming weeks.