This clinical study is part of the BIOVACSAFE project which is funded by the Innovative Medicine Initiative. In this study we will take a small muscle biopsy in order to identify any differences in the response around the actual site of injection compared with responses we measure in blood at the same time.

Inclusion Criteria:

1. The participant is able to read and understand the Informed Consent Form (ICF), and understand study procedures.
2. The participant has signed the ICF.
3. Healthy male participants aged 18-45 years inclusive.
4. BMI between 19-27 kg/m2.
5. Pre-immunised with Hepatitis B vaccine
6. Hepatitis B sAb positive (evidence of vaccine-induced immunity)
7. Hepatitis B sAg and cAb negative (evidence of lack of prior/current HBV infection)
8. Hepatitis C and HIV seronegative.
9. Available for follow-up for the duration of the study.
10. Agree to abstain from donating blood during the study.
11. The participant is, in the opinion of the investigator, healthy on the basis of a, medical history, a symptom directed medical examination and vital signs.

Exclusion Criteria:

1. History of hypersensitivity to any of the vaccine components or a history of any allergy that in the opinion of the investigator would contraindicate participant participation
2. Clinically significant psychiatric, cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, neurological (particularly myasthenia gravis), immunological, or haematological disease or abnormality, as determined by the study physician.
3. Known immune or coagulation disorder or clinically significant abnormalities of platelets, Hb or coagulation on screening labs
4. Known allergy to injected local anaesthetics
5. Unwilling to undergo muscle biopsies
6. Use of steroids or immunosuppressive/immunomodulating drugs either orally or parenterally within 3 months of visit 1.
7. Currently participating in a clinical trial with an investigational or non- investigational drug or device, or has participated in another clinical trial within the 3 months preceding the study.
8. Any condition that, in the investigator's opinion, compromises the participant's ability to meet protocol requirements or to complete the study.
9. Receipt of blood products or immunoglobin, within 3 months of visit 1.
10. Unable to read and speak English to a fluency level adequate for the full comprehension of procedures required in participation and consent.