Sampaio-Barros PD, et al. - The clinicians undertook this work to analyze the possible effect of therapy, disease subtype and severity on H1N1 immunogenicity in patients with systemic sclerosis (SSc). Results approved that the non-adjuvanted influenza H1N1 virus vaccine was a safe and effective approach, independent of SSc clinical subtype, disease severity or therapy. These findings supported the annual influenza vaccination recommendation for these patients.