The new omicron variant is "more of a Frankenstein" than previous virus coronavirus variants, according to one virologist, and vaccine experts are at odds over how well current vaccines will provide protection against it.

The omicron variant: The 'good,' 'bad,' and 'ugly' scenarios

A 'Frankenstein' variant

According to Alex Sigal, a virologist heading a team of researchers at the Africa Health Research Institute, the new variant is "probably the most mutated virus we'd ever seen." However, Sigal added that he believes existing Covid-19 vaccines will continue to protect people against severe disease and hospitalization.

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Similarly, Ugur Sahin, BioNTech co-founder, said that the Pfizer-BioNTech vaccine not only creates antibodies that prevent infection from occurring, but also creates T lymphocytes that attack cells after the body has been infected. Sahin argued that, even if omicron can evade antibodies, it would likely be vulnerable to T lymphocytes.

"Our message is: Don't freak out, the plan remains the same: Speed up the administration of a third booster shot," Sahin said.

Luke O'Neill, an immunologist and chair of biochemistry at Trinity College Dublin, said Sahin's assumption makes sense from an immunological perspective. "There is optimism that the T-cells will hold the line—they are very good at stopping severe disease," O'Neill said.

However, Stanley Plotkin, a scientist who has developed many vaccines, said Sahin's assumptions were "gratuitous and without any proof." Plotkin said so far there's little evidence to suggest T-cells could fully protect against severe symptoms if a virus evades antibodies.

Further, Stéphane Bancel, CEO of Moderna, said, "There is no world, I think, where [the effectiveness] is the same level … we had with [the] Delta [variant] … I think it's going to be a material drop. I just don't know how much because we need to wait for the data. But all the scientists I've talked to … are like, 'This is not going to be good.'"

However, former FDA commissioner Scott Gottlieb on Monday said, "There's a reasonable degree of confidence in vaccine circles that [with] at least three doses … the patient is going to have fairly good protection against this variant."

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Angelique Coetzee, national chair of the South African Medical Association, said that so far, vaccinated patients who have tested positive for omicron "have no complication." She noted that the nation's hospitals were not overwhelmed by omicron patients, and most of those hospitalized were not fully vaccinated. Additionally, most patients she had seen did not lose their sense of taste and smell, and had only a slight cough, the New York Times reports.

"I have seen vaccinated people and not really very sick," Coetzee said. "That might change going forward, as we say, this is early days. And this is maybe what makes us hopeful."

Could omicron 'outcompete' delta?

Separately, Adrian Puren, acting executive director of South Africa's National Institute for Communicable Diseases, said he believes omicron could become more pervasive than the delta variant. "We thought what will outcompete delta? That has always been the question, in terms of transmissibility at least … perhaps this particular variant is the variant," Puren said.

William Schaffner, a professor of preventive medicine at Vanderbilt University School of Medicine, said that while nothing is certain yet, "it looks as though [omicron] will be as infectious as delta."

As for how long it will take to answer questions about omicron, including its transmissibility and virulence, Tara Smith, an epidemiologist at Kent State University, said at minimum "it will take a month to get some preliminary data, and quite possibly longer to really know the fuller picture. We also won't know about real-world experience in vaccine breakthroughs until that time." (Jacobson, Kaiser Health News, 11/30; Jacobs, New York Times, 11/30; Pérez-Peña, New York Times, 11/30; Choi, The Hill, 11/30 [1]; Jenkins, The Hill, 11/30; Choi, The Hill, 11/30 [2]; Pancevski, Wall Street Journal, 11/30; Schnell, The Hill, 11/30; Smyth, Financial Times, 11/30; Patta, CBS News, 11/30)