Before all rising sixth-grade students return to school in August, each must receive a Tdap immunization.

The state Department of Public Health changed the age required for the shot from 13-14 years old to 11-12 years old, a condition all students must fulfill.

Tdap, a combination immunization of tetanus, diphtheria and acellular pertussis, will replace the previously required combination tetanus and diphtheria shot.

The Dallas County Heath Department will offer free Tdap immunizations on July 23 for students and adults.

“We will give a tetanus shot to anyone desiring to have a tetanus shot, or have not had one in the past 10 years, adults included, but we are targeting the 11-and 12-year-olds,” said Jo A. Marshall-Kine, Dallas County Health Department clinic coordinator.

Funding from the Center for Disease Control provided the state with funding to offer the free Tdap immunizations at county heath departments, which cost the state health departments $28 a shot.

“They are trying to offer vaccines in clinics to alleviate the rush in the fall before schools, so people need to take advantage of these clinics all during the summer,” said Walker Sims, director of the immunization division with the state Department of Public Health.

If students do not receive the vaccine from this clinic, it is the requirement of the child and family to arrange an appointment with a physician to administer the immunization.

Tetanus enters the body through a cut or wound, causing lockjaw or painful tightening of the muscles. Diphtheria and pertussis, also known as whooping cough, spread from person to person.

Diphtheria causes a thick covering on the back of the throat, leading to breathing problems, paralysis, heart failure or death.

Pertussis causes coughing spells in infants so intense they cannot eat, drink or breathe. This can cause pneumonia, seizures, brain damage or death.

Teenagers and adults with pertussis are most likely to expose it to infants.

The clinic will be open from 8:30 a.m. until 4 p.m. at 100 Samuel O. Mosley Dr. Appointments not necessary. For more information, contact the Dallas County Health Department at 877-2804.