What happened
Pfizer (PFE -2.29%) was up 1.6% late this morning after the company -- along with partner BioNTech (BNTX -2.01%) -- indicated it will begin seeking authorization for a COVID vaccine booster next month. The push is on as the Delta variant becomes the dominant strain of the virus in more regions.

Image source: Getty Images.
So what
Although both companies have indicated the boosters would be needed, it's the first official move toward making the extra jabs a reality. The pair cited a statement from Israel's health ministry claiming the vaccine's efficacy declined six months after vaccination. That contradicts findings in the U.K., where officials said the Pfizer-BioNTech vaccine was 88% effective at preventing symptomatic infection from the Delta variant of the SARS-CoV-2 virus.
For their part, regulator agencies in the U.S. have yet to match the urgency of the companies. While Pfizer and BioNTech have billions to gain if the boosters are authorized, the Food and Drug Administration, the Centers for Disease Control and Prevention, and the National Institutes of Health have called for scientific rigor. They pushed back on the booster idea, stating explicitly, "Americans who have been fully vaccinated do not need a booster shot at this time."
Now what
Pfizer will share data for a third shot of its vaccine in August and likely file for Emergency Use Authorization shortly after. For now, it looks like authorization of the booster will rest on what level of protection the U.S. agencies deem sufficient.
Meanwhile, the partners are busy designing a vaccine to specifically target the spike proteins of the Delta variant. As long as regulatory agencies oblige, the companies hope to begin testing that shot in humans next month.