If the vaccine type is unknown, but you have documentation, simply pick up the series where you left off and give dose 2 now—you never have to restart the vaccine series. The patient will need a total of three doses since the only 2-dose series option is for Heplisav-B. If you use Heplisav-B, complete the vaccination series by giving a dose now and a second Heplisav-B dose at least 4 weeks later. If you use any other HepB vaccine product, use a minimum interval of 8 weeks between dose 2 and dose 3 to complete the series. See the CDC’s recommended immunization schedule for details, available at www.cdc.gov/vaccines/schedules/hcp/imz/adult.html.