Figure 3From: Impact of anti-rheumatic treatment on immunogenicity of pandemic H1N1 influenza vaccine in patients with arthritisProportion (%) of patients with positive immune response, that is seroconversion (defined as prevaccination titers <10 and postvaccination HI titers ≥40 or a ≥4-fold increase in HI titers), in different treatment groups stratified according to the number of doses of vaccine. HI, hemagglutination inhibition.Back to article page