LA JOLLA (NEWS 8) - The San Diego VA Hospital in La Jolla said that as many as 1,800 patients may have been injected with a compromised flu vaccine.

A batch of flu vaccine products was stored in a defective refrigerator that failed to keep them at the required temperature, rendering all vaccine products inside ineffective, the hospital said Thursday.

"It's hard enough getting people to get their flu vaccine, and again my commitment is this is an unacceptable situation and we have asked our veterans to come in and help us with," said Dr. Robert Smith, VA San Diego Healthcare Director. 

The vaccine was given between October 10th and October 13th at the VA Hospital and its clinics, but the problem was discovered on October 13 during a routine facility inspection at the hospital.

"We've recalled it - as soon as we found out about it we recalled all of their vaccines. There is a period of time those four days where it was mixed in with those that were effective. We don't know who got what," said Dr. Smith. 

Officials said there is no way to determine if the vaccines inside the faulty fridge were compromised, but the hospital is working to reach out to everyone who may have been injected by mail. Officials also said that there are no negative effects for those given a defective vaccine.

The hospital said that more than 1,500 veterans and 300 employees were given potentially defective shots.

"There isn't any risk from this vaccine. It's not that's contaminated. It's not that it has side effects, but we can't be sure it's effective. In fact, it might be effective, but we can't be certain," said Dr. Smith. 

If you had a flu shot at the VA hospital and receive a letter from the Hospital in the mail you are encouraged to go back and get another one.