People may want to change their holiday plans, given the new Omicron variant of COVID-19, experts say. EPA-EFE/FRIEDEMANN VOGEL
Dec. 16 (UPI) -- The emergence of the Omicron variant of COVID-19 in the United States most likely means many people need to reconsider holiday plans, particularly if they involve friends and family members made vulnerable by the virus, experts said Thursday.
Official estimates suggest 3% of cases nationally involve the new variant, first identified in South Africa in late November, based on figures from the Centers for Disease Control and Prevention.
However, the more-contagious variant is responsible for as many as 13% of infections in New York and New Jersey, a point of entry for many international travelers into the United States, the CDC estimates.
In addition, an assessment of 43 documented cases with the Omicron variant found that 30% occurred in people who not only were fully vaccinated, but also received booster doses, the agency announced earlier this week.
Although it is possible the new strain causes more mild illness than the Delta variant, which still is the most common one in circulation in the United States, older adults and those with weakened immune systems due to illness are still at risk, according to global health expert Dr. Michael H. Merson.
With the emergence of the new strain, everyone considering travel and family gatherings over the holidays should ensure that all family members age 5 and older are fully vaccinated, if not "boosted," said Merson, visiting professor of global health at New York University.
Using rapid testing and "knowing risk for family and friends" also can help keep people safe, he said on a call with reporters hosted by NYU.
"Even if you have milder disease, if you have more cases, you're going to have more deaths," Dr. Celine R. Gounder, who serves on President Biden's COVID-19 Task Force, said on the call.
"On a population level, Omicron could be just as deadly as Delta, particularly if more people who are vulnerable get sick," said Gounder, a clinical assistant professor at NYU.
South Africa reported a record-high number of new COVID-19 cases earlier this week -- nearly 38,000 -- and officials there believe the new surge has been fueled by Omicron.
Despite the high number of cases, though, hospitalizations in the country remain relatively low, suggesting that the variant causes milder illness.
However, that may be because many of the people infected with the new variant already had antibodies against the virus due to previous illness, experts said.
Antibodies are proteins produced by the immune system to help fight off viruses.
The Omicron variant contains 32 genetic mutations to the virus' so-called spike protein, the part of its cells that allow it to infect humans, research indicates.
The spike protein also serves as the target for the three vaccines -- from Johnson & Johnson, Moderna and Pfizer-BioNTech -- currently available in the United States.
The degree of genetic mutation to the spike protein could be enough to make it at least somewhat resistant to the vaccines, meaning they offer reduced protection against serious illness from the virus.
"Having a lot of mutations does not mean a variant is more transmissible or more infectious," Elodie Ghedin, a virus genomics expert with the National Institute of Allergy and Infectious Diseases, said on the call.
"The question is, 'How do these mutations impact our diagnostics, our preventives and our therapeutics?'" said Ghedin, who is also part of the affiliate faculty at New York University's Center for Genomics and Systems Biology.
Preliminary data suggests the that shots from Moderna, in a study that has not yet been peer-reviewed, and the Pfizer-BioNTech vaccine, in a separate study published this week, are less effective against Omicron. And Dr. Paul Burton, chief medical officer at Moderna, told parliament in Britain that reports that the variant is less deadly are premature.
However, all three vaccines appear to protect well against the variant in people who have received a booster dose, NYU's Ghedin said.
Concern exists that Omicron may not respond as well to monoclonal antibodies -- lab-created immune proteins delivered by transfusion and a key treatment for people with serious illness, she said.
In addition, currently available at-home rapid tests for COVID-19 may not be able to detect the variant, given its genetic mutations, according to infectious disease specialist Bronwyn MacInnis, who spoke on an earlier call with reporters on Tuesday.
"There is much more that we don't know about this variant than we do regarding severity," said MacInnis, director of pathogen genomic surveillance at the Broad Institute of MIT and Harvard, a research organization based in Cambridge, Mass.
"We absolutely need to take this seriously," she said.
Because of all the unknowns surrounding Omicron, and the ongoing surge in cases linked with the Delta variant in many parts of the United States, MacInnis is advising people to change their plans.
"Personally, I have already changed plans for the holidays," MacInnis said on the call.
"I am thinking about family members and the broader community around me, and that feels like the right thing to do," she said.
Even if the variant causes less severe illness from COVID-19, it is still the "most transmissible variant we've seen, and most immune resistant," infectious disease specialist Jacob Lemieux said on the call.
The surge in cases in South Africa is significant, given that the country is in the Southern Hemisphere and, thus, entering summer, rather than winter, said Lemieux, a staff physician at Massachusetts General Hospital in Boston.
The overlap between the Delta and Omicron variants with the seasonal flu in the United States could further tax an "already overwhelmed" healthcare system, he said.
"I expect we will see a twin Delta and Omicron surge during the holidays because our Delta surge is ongoing and worsening and we may now have an Omicron wave superimposed on that," Lemieux said.
"The combination of these two surges together is going to place even more stress on an already stressed healthcare system, so while we're all tired of COVID-19 and want this to go away, we need to take a step back and say, 'It's highly likely Omicron will come to your holiday gathering," he said.