Daniel Pockett/Getty A dose of Pfizer's COVID-19 vaccine
Pfizer and BioNTech analyzed blood samples from two types of people — those who had just the two-dose series of the vaccine and those who had that plus a third booster dose. Those with just the two doses had much lower antibody levels that would protect them against omicron, in comparison to their antibody levels with previous variants like delta. That raised concerns that the original vaccination series "may not be sufficient to protect against infection" from omicron, the companies said.
That changed, though, for people who had a booster dose. With the added antibodies from a third vaccine dose, blood work showed that they would be able to fight off the omicron variant.
The tests are preliminary, not peer-reviewed and may differ from real-world usage, but as the world scrambles to understand the new variant and just how quickly it spreads, the news that Pfizer's current vaccine is effective against omicron comes as a relief.
"Our preliminary, first data set indicate that a third dose could still offer a sufficient level of protection from disease of any severity caused by the Omicron variant," said Dr. Ugur Sahin, the chief executive officer of BioNTech.
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The companies also added that while two doses may not prevent any COVID-19 illness as well as three doses, "vaccinated individuals [with two doses] may still be protected against severe forms of the disease."
And so far, it appears as though omicron produces a less severe illness than delta, regardless of vaccination status. While the variant is likely the most contagious one yet, based on its high number of mutations, the majority of cases have been mild or asymptomatic.
"Clearly, in South Africa, omicron has a transmission advantage," Dr. Anthony Fauci, the U.S.'s top infectious disease expert, told CNN. "Although it's too early to make any definitive statements about it, thus far it does not look like there's a great degree of severity to it."
"But we've really got to be careful before we make any determinations that it is less severe, or really doesn't cause any severe illness comparable to delta, but thus far the signals are a bit encouraging regarding the severity," he continued.
As health experts work to learn more about omicron, Fauci is urging Americans to get vaccinated or get their booster dose.
"It is absolutely essential that unvaccinated people get vaccinated and the vaccinated people get boosters," he said previously. "We know now clearly that when you get a booster shot ... you dramatically increase the level of protection [you have]."
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