MURRAY, Utah (ABC4) – Public health officials continue to say COVID-19 vaccines are highly effective, but some fully vaccinated individuals are still becoming infected with the virus.

Vaccine efficacy slightly varies based on the vaccine, according to public health officials and the Centers for Disease Control and Prevention, who continue to say while there’s the possibility a person could still become infected, they’re much safer getting the shot rather than not.

And while no shot is 100% effective at preventing a person from contracting COVID-19, Dr. Eddie Stenehjem, an Intermountain Healthcare infectious disease physician, said that means vaccinated individuals can become infected and transmit the virus.

Utah Department of Health data shows nearly 1.5 million Utahns are considered fully vaccinated against the virus. And more than 2,000 of them have become infected post-vaccination.

The CDC reports breakthrough cases can happen with any vaccine, but say it’s possible a person could get infected just before or after vaccination, or if variants evade the vaccine.

For those who catch coronavirus after vaccination, research suggests a person may be asymptomatic, and if a person does show symptoms, cases are often mild.

“People that do get infected after vaccination have lower viral burdens in their upper respiratory tract, which likely is going to lead to less transmission, not no transmission, but less transmission,” Stenehjem said.

So, will asymptomatic cases in our vaccinated population slow the state’s progress in reaching herd immunity?

“Whether or not herd immunity is even feasible I think is a big question. I think what we have to realize is that the more and more our communities get vaccinated, the less transmission we’re going to have,” Stenehjem said.

The CDC is monitoring breakthrough cases and looking to identify any unusual patterns such as trends in age, gender, health conditions, or variants. They report so far that no unusual patterns have been detected.