Omicron could overtake delta within weeks, experts say

Emily Kopp
Cq-Roll Call

Some experts are warning that although evidence is still emerging, the highly concerning omicron variant is expected to overtake delta within weeks.

“I do expect omicron to displace delta in the coming weeks,” said Stephen Kissler, a disease modeler at the Harvard T.H. Chan School of Public Health, in a briefing Tuesday. “Unfortunately, just in time for the new year, we’re going to see quite a lot of omicron spreading.”

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“The time frame for that is going to vary quite a bit” across the country, Kissler said. “In places that have already seen an increase in transmission, in the next six to eight weeks is pretty reasonable. … By the time we’ve detected the omicron variant, it’s already been in circulation for quite awhile, so that may even eat into that eight-week period.”

Earlier Tuesday, Pfizer CEO Albert Bourla speculated at an event hosted by The Wall Street Journal’s CEO Council that omicron will likely lead to millions of COVID-19 cases.

“Right now, the cases are in the dozens. In a few weeks, it will be in the millions,” said Bourla. “We will have a good understanding before the year’s end as to what exactly that means as far as its clinical manifestation.”

White House Chief Medical Adviser Anthony Fauci said at an administration briefing Tuesday that early laboratory data is expected next week on the efficacy of vaccines against the omicron variant.

The data will come by midweek from tests on how well the blood of vaccinated people knocks back a pseudovirus approximation of the omicron variant. By later next week, data will emerge on the efficacy of the vaccines against a live virus.

A man completes paperwork prior to getting shots at a vaccination clinic at LifePath Christian Ministries Wednesday, Dec. 1, 2021. LifePath partnered with community organizations to offer the clinic, providing free COVID-19 shots, boosters and flu shots at its York City men's shelter. Vaccines for age-eligible children were also available. The clinic provided vaccinations for about 70 people.  Bill Kalina photo

Centers for Disease Control and Prevention Director Rochelle Walensky emphasized new CDC guidance updated Monday night recommending a rapid test before any indoor gatherings.

“When you’re gathering together, for example, for the holidays in a multigenerational household, in addition to doing those other prevention interventions 1 / 8like vaccination and mask-wearing in public3 / 8, you might want to do a test,” she advised.

Currently, there are about 103,800 COVID-19 cases, 6,800 hospitalizations and 1,100 deaths from all strains per day, overwhelmingly driven by delta, Walensky said at the briefing with Fauci and other officials.

The omicron variant has been detected in 18 states, she said.

“We expect that number to increase,” Walensky said.

The CDC collaborated with 25 states and major cities to investigate potential cases, including cases tied to a 53,000-person New York City anime convention, Walensky added. Data from the convention could provide early epidemiological evidence about the variant’s transmissibility.

The suspicions that omicron will overtake delta within weeks are based on the variant’s trajectory in South Africa, although Fauci noted the country is less vaccinated than the United States and is believed to have a higher proportion of immunocompromised people.

Biden’s health advisers also responded to criticism by some infectious diseases experts that ensuring private insurance coverage for rapid tests in mid-January won’t be enough to stave off omicron, after Press Secretary Jen Psaki received blowback for comments about the issue at a White House press briefing Monday perceived as flippant.

“We do want to make sure that people have access to free tests, but our approach is not to send everyone a test independent of their need or desire to get tested,” White House COVID-19 Response Coordinator Jeff Zients said Tuesday. “We believe the most efficient and effective approach is more nuanced than that.”

Concerning data

Kissler said the large population of previously infected people in South Africa following a delta surge pointed to omicron evading prior immunity.

“Presumably if delta had been protective against omicron in a very large way, against the transmission of omicron, I don’t think we would have seen as rapid an increase in omicron cases as we have,” he said.

More recently, the United Kingdom has seen an increase of test results that show “S-gene target failure,” an early indicator of a variant that has mutated so much that it evades one of the test’s markers, which could signal omicron is comprising a growing share of cases, despite plenty of delta cases spreading, Kissler said.

Bourla cautioned it could be a few more weeks before there is more clarity on whether the vaccines designed to combat the original Wuhan strain protect against the omicron variant.

“What we need to see is whether the current one is providing an umbrella of protection that is solid enough, which is way preferable,” said Bourla. “The first data will come from the lab,” where the blood of people vaccinated with two doses or three doses will indicate how effective it is.

Pfizer and its partner BioNTech started work on an omicron-specific vaccine in November and if it’s needed, it could be deployed as soon as March, Bourla said.

While early reports suggested omicron may be less severe, that does not ensure that the epidemiology of COVID-19 won’t take a turn for the worse, the experts emphasized.

“If you could have a variant that was 10 percent more severe or 10 percent more transmissible, which would you choose? And your intuition might tell you you’d rather have something that’s more transmissible,” Kissler said. “But because of the nature of exponential growth, with a variant that’s 10 percent more transmissible, you end up with a far larger total number of infections, hospitalizations and deaths than you would with a variant that was 10 percent more severe.”

“Unless it’s much less severe than what we’ve seen previously, which I think is unlikely, I think that it will still cause quite a bit of strain on our health care system and be something that we have to contend with in the coming months,” Kissler continued.

“I don’t think it’s good to have something that spreads fast. Something that spreads fast can infect millions of people, and you might have a new variant,” said Bourla. “You don’t want that.”

Zients touted rising vaccination rates amid expanded eligibility for booster shots, shots for children ages 5 to 11 and fears about the new variant.

Zients said the 12.5 million vaccines administered last week was the highest rate since the spring, when supply and eligibility were still being expanded and demand for first shots among adults remained high.