Pfizer, BioNTech Working On COVID-19 Booster Shot Targeting Delta Variant

Pfizer Inc PFE and BioNTech SE BNTX announced Thursday that they are developing a COVID-19 booster dose intended to target the delta variant.

What Happened: The companies expect to shortly seek U.S. authorization for a third dose of its vaccine.

The companies said that though they believe the third shot of their current two-dose vaccine has the potential to preserve the "highest levels" of protection against all currently known variants, including delta, they are "remaining vigilant" and developing an updated version of the vaccine.

"As seen in real-world evidence released from the Israel Ministry of Health, vaccine efficacy has declined six months post-vaccination, at the same time that the Delta variant is becoming the dominate variant in the country," the companies said in a written statement.

"These findings are consistent with an ongoing analysis from the companies' Phase 3 study," they said. "That is why we have said, and we continue to believe that it is likely, based on the totality of the data we have to date, that a third dose may be needed within 6 to 12 months after full vaccination."

Clinical studies could begin as early as August, subject to regulatory approvals, the companies said.

The first batch of the mRNA for the trial has already been manufactured at BioNTech's facility in Mainz, Germany.

Why It Matters: The announcement comes the same day Olympics organizers said they are banning all spectators from the games this year after Japan declared a state of emergency amid a wave of new COVID-19 infections due in part to the delta variant.

Hours after Pfizer / BioNTech signaled its intention to file for emergency use authorization for its COVID-19 booster shot, a joint CDC and FDA statement said fully vaccinated Americans "do not need" an extra dose at this time. 

"People who are fully vaccinated are protected from severe disease and death, including from the variants currently circulating in the country such as Delta," the statement said. "People who are not vaccinated remain at risk. Virtually all COVID-19 hospitalizations and deaths are among those who are unvaccinated." 

Price Action: BNTX shares are up 3.2% at $214.67, and PFE stock is up 1.6% at $39.87 during the market session on the last check Friday.