SAN ANTONIO – The San Antonio Metropolitan Health District has confirmed two “breakthrough” cases of COVID-19 among vaccinated people in Bexar County.

The two infections were confirmed Friday by Dr. Anita Kurian, the assistant director of Metro Health, and are the only two “breakthrough” cases reported so far.

“We are investigating two cases of possible COVID-19 vaccination breakthrough infections in Bexar County,” Dr. Kurian said in a statement.

A breakthrough case is someone who tests positive for COVID-19 more than two weeks after being fully vaccinated.

Dr. Kurian said in an interview with KSAT Friday that these two individuals with “breakthrough” COVID-19 cases are less likely to transmit the illness to others and could have mild symptoms, given that both individuals are fully vaccinated.

It’s unclear which vaccines the individuals received, how long they were into their vaccination period or how severe their infections are.

According to the CDC, COVID-19 vaccines are still very highly effective at preventing COVID-19 infections, although no vaccine is 100% effective.

The Moderna vaccine has been found to be 94.1% effective at preventing COVID-19 illness in those who have received two doses of the vaccine with “no evidence of being previously infected.”

People must be 18-years-old or older to receive the Moderna vaccine, according to health officials. The vaccine will reach its full effectiveness two weeks after an individual’s second dose.

For the Pfizer vaccine, health officials have found that it is 95% effective at preventing COVID-19 illness two weeks after an individual has received both doses. The Pfizer vaccine is currently approved for people 16-years-old or older.

Johnson & Johnson is just a single dose and has been found to be 85% effective at preventing COVID-19 illness 28 days after vaccination.

CDC officials said if you choose to get a COVID-19 vaccine, you won’t be infected with the live virus, nor will you get COVID-19 from the vaccine itself.

The vaccine typically takes a few weeks for the body to build immunity against the virus after vaccination, according to the CDC.

It’s possible that someone could be infected with the virus that causes COVID-19 “just before or just after vaccination and still get sick,” the CDC said. This is due to the vaccine not having enough time to build the body’s immune response.

It’s unclear what led to the positive COVID-19 breakthrough cases in Bexar County. This is a developing story and we’ll bring more updates as they become available.

More on KSAT:

200+ people got vaccinated in Bexar County without revealing their age, Metro Health confirms

Coronavirus update San Antonio, April 1: Metro Health reports 249 new COVID-19 cases, 2 new deaths