Early studies suggest the omicron variant, while highly transmissible, causes less severe illness than the deadly delta strain of the coronavirus, Dr. Anthony Fauci said Wednesday.
“All indications point to a lesser severity of omicron versus delta,” said Fauci, President Joe Biden‘s top health advisor and the director of the National Institute of Allergy and Infectious Diseases, during a White House press briefing on Covid.
“The data are encouraging, but still in many respects preliminary,” Fauci said.
But “we should not become complacent,” he noted, because the “extremely high volume” of omicron cases could still overwhelm some health-care systems even if the new variant causes fewer hospitalizations on average.
“The risk of severe disease from any circulating variant, including Omicron is much, much higher for the unvaccinated,” Fauci added. “And so, adults and children who are eligible, get vaccinated, and vaccinated people, get boosted when eligible.”
Fauci’s analysis came as Covid cases, fueled by omicron’s rapid spread, hit record highs in many nations, including the U.S. Hospitalizations are also rising, but not with the same speed as new cases. However, hospitalizations usually lag new infections by several days.
Fauci said “the pattern and disparity between cases and hospitalization strongly suggest that there will be a lower hospitalization-to-case ratio when the situation becomes more clear.”
More children are being infected with omicron, Fauci said. But he noted that “many children are hospitalized with Covid, as opposed to because of Covid,” adding no final determination has been made about the variant’s severity in kids.
The omicron variant also shows “a degree of immune evasion” from antibodies, including those induced by the currently available vaccines, Fauci said. But booster shots “bring back up that degree of protection to a level that is approximating what it was before,” he said.
“So boosters are critical in getting our approach to omicron to be optimal,” Fauci said.
He then highlighted some recent data collected from South Africa, the United Kingdom and the U.S., all of which suggested a lower risk of hospitalization or death from omicron compared with other waves of Covid.
The South African study also showed fewer admissions to the intensive care units, fewer patients in need of supplemental oxygen and shorter hospital stays for omicron cases versus infections from prior waves of the virus, Fauci said.
A study by the UK Health Security Agency, meanwhile, showed the risk of hospital admission for an omicron infection is about 40% of the risk posed by the delta variant, Fauci noted.
Data from another study conducted by Imperial College London “indicate an overall significant reduction in the risk of hospitalization for Omicron compared to delta,” Fauci said.