I undersøgelsen af virkningens varighed, baseret på antistofmængden, blev det påvist, at revaccination med en enkelt dosis gav en klar booster- reaktion (dvs. endnu større antistofdannelse end ved basisvaccinationen).
In the study of the duration of effect, based on antibody levels, it was shown that revaccination with a single dose resulted in a clear booster response (that is, the resultant antibody levels were even higher than after the basic vaccination).