Pfizer said Thursday it wants to expand its COVID-19 booster shots to healthy elementary-age kids.

U.S. health authorities already urge everyone 12 and older to get one booster dose for the best protection against the newest variants — and recently gave the option of a second booster to those 50 and older.

Now Pfizer says new data shows healthy 5- to 11-year-olds could benefit from another kid-sized shot.

In a small study, 140 youngsters who’d already gotten two shots were given a booster six months later, and researchers found the extra shot generally revved up their immune response. But a closer look at 30 of the children found a 36-fold increase in virus-fighting antibodies, levels high enough to fight the super-contagious omicron variant, Pfizer and its partner BioNTech said in a press release.

The data has not been published or vetted by independent experts.