If HPV vaccine is given subcutaneously (Subcut) instead of intramuscularly (IM), does the dose need to be repeated?

Yes. No data exist on the efficacy or safety of HPV vaccine given by the Subcut route. All data on efficacy and duration of protection are based on a vaccine series administered by the IM route. In the absence of data on Subcut administration, CDC and the manufacturer recommend that a dose of HPV vaccine given by any route other than IM should be repeated. There is no minimum interval between the invalid (Subcut) dose and the repeat IM dose.