(KCAU) — An Iowa doctor said while COVID-19 vaccines are still effective, the omicron variant presents a unique challenge.

Dr. Jeff Brock, a pharmacy specialist with infectious diseases for MercyOne, said more vaccinated people are getting COVID-19 because the omicron variant has protein changes that help it avoid our immune system, but he said the vaccine still plays an important role in the fight against the virus.

“Vaccines don’t necessarily prevent infection,” Brock said. “Vaccines are designed to prevent disease from the virus, which it is doing, although people are getting infected after they’ve been vaccinated, generally they have mild to moderate symptoms which is what we want.”

He said one to two doses of the vaccine is not very effective against the omicron strain, but a couple of weeks after getting the booster dose, people are likely to have a stronger immune response and more protection against the omicron strain.

The Iowa Department of Public Health said that out of the nearly 900 patients hospitalized with COVID-19, Iowans that aren’t vaccinated make up 81 percent.