Table 4

Seroconversion rates (percentage of subjects with seroconversiona or a significant increase in HI titresb in subjects without pre-vaccination immunoprotection)


Seroconversion rates, %

Viral strain
Sub/MF59™
Subunit

A/H1N1c
83.3
80.0
A/H3N2d
85.1*
66.2
Be
33.4
25.8

aSeroconversion is defined as negative pre-vaccination serum (i.e. haemagglutinin inhibition [HI] titre <1:10) and post-vaccination HI titre ≥ 1:40; bSignificant increase is defined as ≥ 4-fold increase from non-negative (≥ 1:10) pre-vaccination HI titre; cNumber of subjects: Sub/MF59™, 6; Subunit, 5; dNumber of subjects: Sub/MF59™, 288; Subunit, 152; eNumber of subjects: Sub/MF59™, 359; Subunit, 183

*P < 0.001 versus the Subunit group

Sub/MF59™, MF59™-adjuvanted subunit influenza vaccine; Subunit, non-adjuvanted subunit influenza vaccine

Li et al. Immunity & Ageing 2008 5:2   doi:10.1186/1742-4933-5-2