MINNEAPOLIS (WCCO) — Scientists have been trying to learn more about how effective the vaccines and booster doses are against the more contagious Omicron variant. Meanwhile, the surge in omicron variant cases has lead to an expansion of booster shots in the U.S.

The Food and Drug Administration approved Pfizer’s COVID-19 booster shot for children ages 12 to 15 on Monday. That same day the U.S set a global record for new COVID cases in the pandemic — more than 1 million.

READ MORE: Study: Minnesota's Racial Wealth Gap Is 3rd-Worst In Nation

“As long as we have this many people unvaccinated, as long as we don’t have masking, this will continue in one iteration or another,” said Dr. Gregory Poland, a vaccinologist at the Mayo Clinic in Rochester.

Poland says booster shots offer more protection against omicron, which means a positive case will likely lead to no symptoms or symptoms that are mild.

“People who are fully immunized, boosted, may still get infected, but the vast majority of the disease is blocked in them,” Poland said.

Pfizer said lab tests showed their booster increased antibodies 25-fold. The Centers for Disease Control also updated recommendations Tuesday on the timing of Pfizer’s booster shots.

READ MORE: Police Release Photos Of I-394 Shooting Suspect Vehicle, Seeking Public's Help

For anyone over the age of 12, they’d be eligible for a booster five months after the second dose in their vaccine series, instead of six months.

The Minnesota Department of Health estimates around 90% of the state’s positive tests right now are the omicron variant, and that’s showing up in the positivity rate. The seven-day average is up over 12% now. The highest yet recorded was 15% at the start of the pandemic, when testing was tougher to come by.

More than 1.7 million Minnesotans have received a booster dose. But will there be a fourth shot?

“No one knows. What do I think is going to happen? I think we will see a more personalized approach,” Poland said.

MORE NEWS: Minnesota Plans Comeback From Tourism Losses Caused By COVID

The CDC is also now recommending that immunocompromised 5– to 11-year-olds receive an additional primary dose of vaccine 28 days after their second shot. Right now Pfizer’s vaccine is the only authorized for that age group.

Kate Raddatz