EDMONTON -- Alberta Health Services says vaccines given to 131 people to protect them against a potentially dangerous infectious disease may have been ineffective.

The government agency says these people, who were patients receiving treatment for tetanus prone wounds, should get a new shot.

The dTap vaccine also protects against diphtheria and whooping cough.

The patients received the vaccine between Nov. 1 and Jan. 11 at the WestView Health Centre emergency room in Stony Plain.

The agency says it is notifying the 131 patients by letter and there is no threat to the public.

An Alberta government website says tetanus is a bacterial disease that attacks the nervous system and can cause muscle spasms, breathing difficulty, seizures and death.

"Although the risk of tetanus infection is very low, AHS is notifying the patients related to this monitoring error and recommends that those individuals get re-immunized," the agency said in a release Wednesday.

"AHS regrets that this issue has resulted in an impact to our patients and we have ensured that proper monitoring is in now in place."