A Saint Vincent's Medical Center infectious disease specialist says when it comes to COVID-19 boosters, get one now.

Her advice comes on the heels of Pfizer's announcement that results from an initial lab study showed three doses of its COVID-19 vaccine will neutralize the omicron variant, while two doses are significantly less effective.

"We're saying that if you just had your two-dose series, that is probably not sufficient against omicron. It wasn't sufficient this summer against delta," Dr. JoAnne Passalaqua says.

Passalaqua says since early data shows omicron is more infectious than other strains of the coronavirus like delta, and that getting a booster should be a "no-brainer."

"This just makes it a little more urgent. This just says if you were thinking about doing it in the next couple weeks, do it now," Passalaqua says.

Pfizer also announced it is working to develop a vaccine tailored to omicron.

"We're four to six months away from that. Certainly, the most important tool that we have in our toolbox right now is vaccination," she says.