Jefferson Healthcare has notified 150 recent vaccine recipients that they may have received less than the therapeutic dose of the COVID-19 vaccine.

In an announcement last Friday, the hospital district said it discovered about 36 vaccinations — administered between 8:30 a.m. and noon on Thursday, March 4 — did not contain therapeutic levels of the vaccine.

Due to the hospital’s inability to clearly determine when the lower dosages were administered, Jefferson Healthcare opted to notify all 150 patients vaccinated during the period in question.

According to hospital spokesperson Amy Yaley, the error arose when a staff member deviated from the established protocol in preparing the doses.

Typically, in preparing each dose of the vaccine, a vaccine vial is filled with saline from a separate vial and mixed.

The solution containing the vaccine is then drawn into six separate syringes, which are then administered to six patients. The vials are then trashed.

An error in the preparation, though, led to vaccine vials which had previously been filled with saline and drawn into syringes to be refilled a second time with saline and administered to patients, Yaley said.

“A vaccine mixer was attempting to be more efficient with the method and so popped the tops off of a few saline and a few vaccines and mixed and drew and then set ... them to the side,” Yaley explained.

“When you’re done taking those six doses out, there’s still just a little bit left and it looks really similar to how [the vaccine] arrives.”   

Mistaking the spent vials for un-mixed vials, the staff member again diluted the remaining vaccine using saline, resulting in the highly-diluted doses.

Yaley said staff estimated that six vials were affected by the mix-up, since six doses can be taken from each vial, leaving a total of 36 patients who were likely affected.

According to the hospital district, under-dosing the vaccine posed no direct harm to the patients and that it would test each potential recipient for COVID-19 immunity antibodies 21 days after they received the questionable dosage.

If antibody testing shows inadequate levels of the antibodies, the patient will be scheduled for an additional dose of the vaccine another 21 days later.

“We apologize for the inconvenience and concern this has caused our patients,” said Jefferson Healthcare Chief Executive Officer Mike Glenn.

“Holding the trust of our community is not only our aspiration but our highest priority,” he said.