Experts from the Centers for Disease Control and Prevention are examining documentation at the Shelby County Health Department to ensure possible lapses in temperature monitoring didn’t render any already administered Pfizer vaccine shots less effective.
Tennessee’s health commissioner, Dr. Lisa Piercey, says inconsistent record keeping within the health department has left some gaps in data that would confirm vaccines were kept at correct temperatures at all times before people received them.
“We are taking all data available to us on the digital data loggers, on the temperature logs, the transport logs and putting all of these together to try to ensure vaccine stability based on the temperatures that we know about,” she said at a press briefing Tuesday.
The Pfizer vaccine can be stored for up to six months in ultra-cold freezers at a temperature between negative 112 and negative 76 degrees Fahrenheit. Newer federal regulations allow for vials to remain inless extreme freezer conditions for up to two weeks. When a vial is thawed however, it has a shelf life of five days in a refrigerator, but once diluted and put in syringes, there are six hours to get it into an arm.
Double checking to make sure each dose met all of these requirements is a long and detailed process, Piercey says, but she sought to reassure the public that if it is found that any doses administered experienced temperature fluctuations, it is not harmful to one’s health.
“Nothing bad is going to happen if you get an expired vaccine,” she said. “The worst thing that can happen is that it’s just not as efficacious. It’s just not as effective as a temperature controlled or unexpired vaccine would be.”
Piercey also noted that expired vaccines refer to doses that are considered unusable because they are out of the freezer or refrigeration for too long. The vials containing the doses have a separate manufacturer’s expiration date.