Amid little consensus on the best strategy to defend against the Delta variant of the coronavirus, Pfizer is making its pitch to the United States government in hopes of speeding a booster shot to Americans.
The company will meet with FDA officials as early as today, the Washington Post reports. It’s not certain what the company's exact message will be, or how receptive the government will be.
In recent months, Pfizer and its COVID-19 vaccine development partner BioNTech have referenced lab data showing that a third dose of their original mRNA vaccine would “preserve the highest levels of protective efficacy.” Last week, Pfizer’s chief scientific officer Mikael Dolsten, M.D., told the Associated Press that data from the company’s booster study revealed that antibody levels increase five- to 10-fold with a third vaccine.
Further, last Thursday, the companies revealed (PDF) they were developing a tweaked version of the shot which would target the spike protein of the Delta strain. But shortly afterward, the Centers for Disease Control and Prevention and the FDA said that Americans need not be concerned with boosters at this time.
In television interviews on Sunday, President Joe Biden’s top medical adviser, Anthony Fauci, M.D., said it's too soon to tell how the country will deploy boosters. He admitted that officials have observed breakthrough infections among those who have been vaccinated, but he said more data are needed to proceed with a plan for booster shots.
“There are studies being done now ongoing as we speak about looking at the feasibility about if and when we should be boosting people,” Fauci said on CNN on Sunday.
In addition to the Delta-specific booster in development by Pfizer andBioNTech, the companies worked on another variant-specific booster formulation earlier in the pandemic. That formulation will be ready for testing on humans in August.
For months, Pfizer has maintained booster shots would be needed in the fall as antibody levels decline. But Bernstein analysts say that’s not the industry standard, and experts with CDC’s Advisory Committee on Immunization Practices pushed back on the company's stance during a meeting last month.
Boosters will most likely be necessary once there’s a clear drop in vaccine efficacy or as a countermeasure against a particularly evasive variant, not in a declining antibody response, ACIP experts said.