MILWAUKEE -- Police and health officials say a refrigerated truck carrying H1N1 vaccine has been recovered after being stolen from outside a swine flu clinic in Milwaukee.

Health operators officer Raquel Filmanowicz of the city's health department says the truck was taken from the Sarah Scott Middle School after a clinic there closed Thursday.

Filmanowicz says she doesn't know how much vaccine was in the truck, but that it was "compromised" in the theft and can no longer be administered. She doesn't know if the thieves were aware the truck contained H1N1 vaccine.

Milwaukee police media officer Anne E. Schwartz says the truck was later recovered and an investigation is ongoing.

It's unclear if a clinic planned at the South Division High School will go ahead Friday.