http://www.phac-aspc.gc.ca/im/vpd-mev/hepatitis-b_e.html

Booster Doses and Re-immunization

Additional doses of vaccine up to three doses will produce a protective antibody response in 50% to 70% of otherwise healthy people who fail to mount a response after the first series of vaccines. Administration of additional doses with testing for response after each dose should be undertaken when the response to vaccine needs to be ensured. Individuals who fail to respond to three additional doses of vaccine are unlikely to benefit from further immunization.

Post-immunization

The seroconversion rate in healthy people is usually 90% or more, and in children 98% or more. Thus, post-immunization testing for universal programs is not necessary. Post-immunization testing is recommended, however, if it is important to ensure protection against a continual known or repeated potential exposure to hepatitis B.

Schedule and Dosage

Vaccines produced by different manufacturers can be used interchangeably when three or more doses are given, despite different levels of antigen.