Question: is this a 2) strong advice, 1) weak advice 0) no advice?

During the 2011-2013 period, an observational study was performed in Healthcare students (HCSs) trained at a regional university acute-care hospital in North-Western Italy, properly immunized against HBV during infancy or adolescence, in order to evaluate the persistence of seroprotection and to assess the anamnestic response to booster vaccination. 
user
This is no advice
assistant