According to the Centers for Disease Control and Prevention, asking parents or caregivers if they have childhood shot records is one solution. Look through family albums or any documents that have been saved over the years. High schools and colleges may have shot records, but these institutions normally only keep records for up to two years after students leave.
The CDC further notes that checking with previous employers or the military is another way to find lost shot records. Checking with a doctor is another option, but many practices keep records for a certain period of time.
Dr. Vincent Iannelli for About.com mentions that contacting a medical board or medical society is necessary if a doctor has moved or retired. VaccineInformation.org notes that checking with all previous healthcare providers may be necessary, including ones from local clinics and health departments. Medical record storage companies hold records on behalf of retiring doctors and practices that have moved.
According to Iannelli, certain states may have immunization registries where shot records are available. For children's records, office personnel at a pediatrician's office may be able to find lost records through diligent searching. Camps and daycare centers hold vaccination records. If the records cannot be found, receiving the shots again may be necessary, or a doctor can conduct blood tests to see if a patient is immune to diseases that require vaccination.