Pandemic non-adjuvanted influenza A H1N1 vaccine in a cohort of patients with systemic sclerosis.

Objective: To assess the possible effect of therapy, disease subtype and severity on H1N1 immunogenicity in patients with SSc.

Methods: Ninety-two patients and 92 age- and gender-matched healthy controls received adjuvant-free influenza A/California/7/2009 (pH1N1) vaccine. Blood samples were collected immediately before and 3 weeks after vaccination to evaluate antibody responses to the H1N1 virus.