Vaccination adjuvated against hepatitis B in Spanish National Healthcare System (SNS) workers typed as non-responders to conventional vaccines

A Summary: Trial Design: An interventional, phase 4, single group assignment, without masking (open label), preventive clinical trial was carried out in health workers with biological risk in their tasks, who have been filed as non-responders to conventional vaccination against Hepatitis B. Methods: 67 health workers with biological risk in their tasks, who have been filed as non-responders to conventional vaccination against Hepatitis B, were enrolled in the Clinical Trial. All participants were from 18 years up to 64 years old. Inclusion Criteria: NHS workers -including university students doing their internships in health centres dependent on the National Health System (inclusion of students is regulated and limited by specific instructions on labour prevention in each autonomous community)- classified as non-responders. The criteria defining them as non-responders to the conventional hepatitis B vaccine is anti HBsAb titers < 10 mUI/ml following the application of six doses of conventional vaccine at 20 mu g doses (two complete guidelines). The objective of this study was to provide Health workersstaff with an additional protection tool against hepatitis B infection, and to evaluate the efficacy of the adjuvanted vaccine in healthy non-responders to conventional hepatitis B vaccine. The primary outcome was the measurement of antibody antiHBs before the first Fendrix (R) dose and a month after the administration of each dose. Other outcome was collection of adverse effects during administration and all those that could be related to the vaccine and that occur within 30 days after each dose. In this study, only one group was assigned. There was no randomization or masking. Results: The participants were recruited between April 13, 2018 and October 31, 2019. 67 participants were enrolled in the Clinical Trial and included the analyses. The primary immunisation consists of 4 separate 0.5 ml doses of Fendrix (R), administered at the following schedule: 1 month, 2 months and 6 months from the date of the first dose. Once the positivity was reached in any of the doses, the participant finished the study and was not given the following doses. 68.66% (46 out 67) had a positive response to first dose of Fendrix (R). 57.14% (12 out 21) had a positive response to second dose of Fendrix (R). 22.22% (2 out 9) had a positive response to third dose of Fendrix and 42.96% (3 out 7) had a positive response to last dose of Fendrix (R). Overall, 94.02% (64 out 67) of participants had a positive response to Fendrix (R). No serious adverse event occurred. Conclusions: The use of Fendrix (R), is a viable vaccine alternative for NHS workers classified as ''non-responders". Revaccination of healthy non-responders with Fendrix (R), resulted in very high proportions of responders without adverse events. (C) 2020 Elsevier Ltd. All rights reserved.