Tipsheet

Pfizer Says Third Dose Protects Against Omicron, But Is Still Developing Variant Specific Booster

On Wednesday morning, Pfizer and BioNTech released a press release on their vaccine protection against the Omicron variant of COVID-19, which was announced as a "variant of concern" by the World Health Organization (WHO) on November 26. The announcement indicated that three doses of the Pfizer vaccine appear to offer "a more robust protection" than two doses. That being said, there is still a variant-specific dose in the works, which is expected to be available in March. 

The press release detailed, with original emphasis, that the information came about from "an initial laboratory study." It also explained how the vaccines neutralized the Omicron variant. 

A more robust protection may be achieved by a third dose as data from additional studies of the companies indicate that a booster with the current COVID-19 vaccine from Pfizer and BioNTech increases the antibody titers by 25-fold. According to the companies’ preliminary data, a third dose provides a similar level of neutralizing antibodies to Omicron as is observed after two doses against wild-type and other variants that emerged before Omicron. These antibody levels are associated with high efficacy against both the wild-type virus and these variants. A third dose also strongly increases CD8+ T cell levels against multiple spike protein epitopes which are considered to correlate with the protection against severe disease. Compared to the wild-type virus, the vast majority of these epitopes remain unchanged in the Omicron spike variant.

The press release also stated: 

“Although two doses of the vaccine may still offer protection against severe disease caused by the Omicron strain, it’s clear from these preliminary data that protection is improved with a third dose of our vaccine,” said Albert Bourla, Chairman and Chief Executive Officer, Pfizer. “Ensuring as many people as possible are fully vaccinated with the first two dose series and a booster remains the best course of action to prevent the spread of COVID-19.”

“Our preliminary, first dataset indicate that a third dose could still offer a sufficient level of protection from disease of any severity caused by the Omicron variant,” said Ugur Sahin, M.D., CEO and Co-Founder of BioNTech. “Broad vaccination and booster campaigns around the world could help us to better protect people everywhere and to get through the winter season. We continue to work on an adapted vaccine which, we believe, will help to induce a high level of protection against Omicron-induced COVID-19 disease as well as a prolonged protection compared to the current vaccine.”

While news of the variant wasn't widely known until Friday, November 26, the press release claims that it was Thursday, November 25, Thanksgiving, that "the companies started to develop an Omicron-specific COVID-19 vaccine." 

"Based on this experience the companies have high confidence that if needed they can deliver an Omicron-based vaccine in March 2022," the press release further detailed. "The companies have also previously initiated clinical trials with variant-specific vaccines (Alpha, Beta, Delta & Alpha/Delta Mix) and data from these studies will be submitted to regulatory agencies around the world to help accelerate the process of adapting the vaccine and gaining regulatory authorization or approval of an Omicron-specific vaccine, if needed." 

Such news led to some conflicting headlines from the media. 

On Wednesday morning, Twitter indicated that "Pfizer says new study shows that three doses of its COVID-19 vaccine protect against the Omicron variant." Most other outlets went with this focus for a headline. 

However, Spencer Kimball stressed the fourth dose, with his headline reading, "Pfizer CEO says fourth Covid vaccine doses may be needed sooner than expected due to omicron."

It's worth stressing that so far the Omicron variant has led to cases with "mild" symptoms, including in South Africa where it was first discovered, and in the cases that have been detected in the United States.