Moderna and Pfizer Testing Omicron Vaccines: Will They Make Any Difference?

The real value may be in understanding how processes can be made more efficient and how quickly vaccines targeted at new variants can be developed, rather than the actual impact of an omicron-specific vaccine given that variant's relative mildness. JL 

Emily Anthes reports in the New York Times:

Moderna began a study of a booster shot designed specifically to fend off the Omicron variant of the coronavirus, one day after Pfizer and BioNTech said that they had launched a study of their own Omicron-specific shot. After a single dose of the current booster, the level of Omicron-fighting antibodies rose 20 times higher than their peak before the shot. After six months, however, these antibody levels had fallen more than sixfold, though they still remained detectable in all of the booster recipients studied.

Moderna has begun a study of a booster shot designed specifically to fend off the Omicron variant of the coronavirus, the company said on Wednesday, one day after Pfizer and BioNTech said that they had launched a study of their own Omicron-specific shot.

Moderna also announced the results of a small laboratory study suggesting that the protection its authorized booster shot provides against Omicron infections is likely to fade over the course of six months.

After a single dose of the current booster, the level of Omicron-fighting antibodies rose 20 times higher than their peak before the shot, the company said. After six months, however, these antibody levels had fallen more than sixfold, though they still remained detectable in all of the booster recipients studied.

Antibodies against the original version of the virus fell roughly twofold over the same time period, the company said. The results were published in The New England Journal of Medicine on Wednesday.

Stéphane Bancel, Moderna’s chief executive, said in a statement that the company was “reassured” by the persistence of Omicron-neutralizing antibodies six months after the booster shot. “Nonetheless, given the long-term threat demonstrated by Omicron’s immune escape, we are advancing our Omicron-specific variant vaccine booster candidate,” he said.

Although Omicron can evade the antibodies elicited by the authorized vaccines, making breakthrough infections more common, the vaccines still provide strong protection against hospitalization and death.

Moderna’s new study will examine the safety of, and immune responses to, a single Omicron-specific booster dose in about 600 adults. The company will assess the shot’s performance in two groups of volunteers: some who have received two doses of Moderna’s current vaccine and others who have received two doses plus a booster.

The company did not say when it expected to have results.

Pfizer, which plans to enroll as many as 1,420 people in its study, said it expected to have results in the first half of this year.