Your story makes no sense. A blood test uses interchangeable tubes to store blood which are color coded for different types of blood tests. How could someone take blood when the syringe is full with vaccine and has no storage for blood?
Secondly, the hepatitis B vaccine is never injected into a vein.
The vaccination is given as a course of multiple intra-muscular injections. If the vaccine were to given directly into a vein it would not be effective.
"PRESCRIBING INFORMATION
Engerix-B®
Hepatitis B Vaccine (Recombinant)
DESCRIPTION
Engerix-B [Hepatitis B Vaccine (Recombinant)] is a noninfectious recombinant DNA hepatitis B vaccine developed and manufactured by SmithKline Beecham Biologicals.
Engerix-B is supplied as a sterile suspension for intramuscular administration. The vaccine is ready for use without reconstitution; it must be shaken before administration since a fine white deposit with a clear colorless supernatant may form on storage."
HB-II Vax Administration:
Administration: Do not inject IV or intradermally.
Hector