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WHO. Classification of omicron (B.1.1.529): SARS-CoV-2 variant of concern. Accessed Nov. 29, 2021.

Disclosures: Adalja, Biden, Choski, Marrazzo and Moeti report no relevant financial disclosures.
November 29, 2021
3 min read

Omicron variant ‘a cause for concern, not a cause for panic,’ Biden says


WHO. Classification of omicron (B.1.1.529): SARS-CoV-2 variant of concern. Accessed Nov. 29, 2021.

Disclosures: Adalja, Biden, Choski, Marrazzo and Moeti report no relevant financial disclosures.
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President Joe Biden said Monday that his administration is “already working” with COVID-19 vaccine manufacturers “to develop contingency plans for vaccines and boosters” against the omicron variant if they are needed.

“We do not yet believe that additional measures will be needed,” Biden said during a press briefing. “But ... we are prepared.”

 Source: Adobe Stock
Source: Adobe Stock.

At the behest of independent advisors, WHO on Friday classified omicron as a SARS-CoV-2 “variant of concern,” citing its “large number of mutations, some of which are concerning.” According to WHO, preliminary evidence suggests that the variant may carry an increased risk for reinfection.

The variant was first reported to WHO by South Africa on Wednesday. Two days later, the Biden administration announced additional travel restrictions from South Africa and seven other southern African nations — Botswana, Eswatini, Lesotho, Malawi, Mozambique, Namibia and Zimbabwe. Biden said the restrictions will remain in place until they are deemed no longer necessary.

“While travel restrictions can slow the speed of omicron, it cannot prevent it. It gives us time to take more actions,” Biden said. “This variant is a cause for concern, not a cause for panic.”

Other countries have announced similar travel restrictions to slow the spread of the variant. Such measures have been criticized by experts in the past as ineffective and even counterproductive.

Amesh A. Adalja, MD, a senior scholar at the Johns Hopkins Center for Health Security, said travel restrictions will have a “marginal impact” on the omicron’s spread.

Amesh A. Adalja

“However, the travel restrictions will have a chilling effect on the reporting of infectious disease outbreaks if what countries get is punishment,” Adalja told Healio. “This late in the pandemic, there are much better tools that are less blunt to deal with this threat. Also, this travel restriction is not universal, it doesn’t apply to every country with the variant, and was delayed. Politicians often feel the need to do something even if it is the wrong thing and that is the case with his travel ban, as is the case with almost every travel ban.”

WHO urged countries to keep their borders open, saying travel restrictions “may play a role in slightly reducing the spread of COVID-19 but place a heavy burden on lives and livelihoods.”

“The speed and transparency of the South African and Botswana governments in informing the world of the new variant is to be commended,” WHO Regional Director for Africa Matshidiso Moeti, MB, BS, MSc, said in a statement. “WHO stands with African countries, which had the courage to boldly share life saving public health information, helping protect the world against the spread of COVID-19.”

According to WHO, current PCR tests continue to detect the omicron variant. It said several labs have indicated that one of three target genes — the S gene — is not detected by one widely used PCR test, which can be used as a marker for the variant.

“Using this approach, this variant has been detected at faster rates than previous surges in infection, suggesting that this variant may have a growth advantage,” WHO said.

According to Infectious Disease News Editorial Board Member Jeanne M. Marrazzo, MD, MPH, the United States is not as prepared as other countries to detect the variant.

Jeanne Marrazzo

“We don’t have the extensive sequencing and population-based sampling system that the U.K. has pioneered, though some jurisdictions — generally the best funded public health departments or those that partner successfully with academic entities, like in Seattle and New York City — will likely be ahead of the game,” Marrazzo, who directs the division of infectious diseases at the University of Alabama at Birmingham, told Healio.

Marrazzo said the data needed to confirm if antibodies generated by existing COVID-19 vaccines are active against omicron will not be available for at least 1 or 2 weeks.

“What those laboratory tests won’t tell us definitively is whether the available vaccines will have a stronger effect on prevention of infection, prevention of hospitalization, severe illness, and prevention of death,” Marrazzo said. “We can extrapolate based on the ‘strength’ of what things look like in the laboratory, but we’ll need to carefully monitor this in the real world.”

Omicron has still not been detected in the U.S., although experts expect there will be cases. New York City Health Commissioner Dave A. Chokshi, MD, tweeted Monday that the delta variant still accounts for around 98% of sequenced specimens in the city.

“If current vaccines are not as effective against omicron, we will likely start to see an increase in breakthrough infections in people already immunized, including possibly those who’ve had booster doses,” Marrazzo said.



WHO. Classification of omicron (B.1.1.529): SARS-CoV-2 variant of concern. Accessed Nov. 29, 2021.

WHO. WHO stands with African nations and calls for boarders to remain open. Accessed Nov. 29, 2021.