DALLAS (CBSDFW.COM) – New data from the Texas Department of State Health Services shows that out of millions who received the Covid-19 vaccine, 31 patients contracted the disease and died from it since the beginning of January 2021.

Doctors say this proves that the vaccine is effective in stopping severe disease in those who get infected.

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Parkland Hospital’s Chief Medical Officer Dr. Joseph Chang says everyone who has been admitted to the hospital with Covid-19 is unvaccinated.

“If you’re vaccinated, the chance that you would get sick enough to be admitted to hospitals very, very low, and of course that’s good news,” he said.

The good news comes with caution said DFW Hospital Council’s CEO Stephen Love.

He is concerned about Covid-19 vaccination rates in the state.

“If you look at the entire state of Texas, only 49.2% of the people are fully vaccinated,” said Love. “That means 50% of the people that are unvaccinated and subject to this COVID-19 virus.”

“They are playing Russian Roulette with their lives,” he added.

Doctors say to reach herd immunity- at least 70% of the population needs to be vaccinated.

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Some of the North Texas counties haven’t reached that threshold just yet.

VACCINATION RATES BY COUNTY FULLY VACCINATED 12 AND OLDER

As of 7/1/21

Dallas- 49.29
Tarrant– 47.72
Collin– 59.20
Denton — 53.82
Wise – 33.05
Rockwall — 48.66
Ellis– 42.21
Parker– 38.61
Hood– 42.40
Johnson– 37.05
Kaufman – 40.85
Hunt– 32.47

Source: TX DSHS

Doctors are particularly concerned about the new delta variant which is believed to be very infectious.

“Hospitals are telling me is a greater percent of people being hospitalized, have the delta variant. It seems to be more contagious than the original COVID-19,” Love said.

Doctors recommend masking for those who are unvaccinated, especially indoors and in crowded places.

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CLICK HERE for the most up-to-date vaccination rates.