Couple of suggestions:
1. According to HHS.gov, unencrypted email can be HIPAA complaint for some uses (probably don't want to send a positive HIV result this way).
HHS.gov PDF on HIPAA Safeguards at pg. 3
2. Most PDF editing software allows you to add password protection to an existing pdf. (E.g. Adobe Standard ($450), PDF Converter Professional ($50-90)). Print it to a pdf, password protect it, then email it. Voila! Encrypted email!