Non-Adjuvanted Influenza A H1N1 Vaccine Safe, Efficacious in Patients With Systemic Sclerosis

Use of the non-adjuvanted influenza A H1N1 vaccine was shown to be safe and efficacious in patients with systemic sclerosis in a study recently published in Rheumatology.

Systemic sclerosis is a chronic autoimmune disease that affects the skin, blood vessels, muscles, joints, and several organs including the digestive tract, heart, lungs, and kidneys. Because immunosuppressive agents are often used to treat cutaneous and pulmonary involvement in patients with systemic sclerosis — also known as scleroderma —infections, especially in the respiratory tract, are a cause of morbidity and mortality in these individuals. The present study was designed to evaluate the impact of systemic sclerosis and its therapy on humoral immune response to pandemic non-adjuvanted influenza A H1N1 vaccine.

For this study (ClinicalTrials.gov identifier, NCT01151644), adjuvant-free influenza A H1N1 vaccine was administered to 92 patients with systemic sclerosis, and 92 age- and gender-matched controls. Blood samples were obtained immediately before and 3 weeks after vaccination to assess immune response to the vaccine. Vaccine efficacy was evaluated by measuring rates of seroprotection and seroconversion and factor increases in geometric mean antibody titers (FI-GMTs). All participants reported local and systemic adverse events on a 21-day symptom diary card.

Patients with systemic sclerosis were mostly women (91%); 61% had limited cutaneous involvement, 12% had diffuse cutaneous involvement, and 57.6% were receiving immunosuppressive therapy. Comparable overall seroprotection and seroconversion rates were observed among both groups (P =.20 and P =.61, respectively). Additional investigation into the possible effects of disease and treatment demonstrated similar rates of seroprotection and seroconversion among patients with limited and diffuse cutaneous involvement systemic sclerosis (seroprotection rate, P =.62; seroconversion rate, P =.66), patients with severe vs mild/moderate cutaneous involvement (seroprotection rate, P =1.0; seroconversion rate, P =.45), and patients receiving vs not receiving immunosuppressive therapy (seroprotection rate, P =.26; seroconversion rate, P =.10).

The occurrence of mild local and minor systemic reactions was similar among participants with diffuse vs limited systemic sclerosis (P =.70 vs P =.32) and in patients with vs without severe cutaneous involvement (P =.59 vs P =.28).

The researchers strongly recommend seasonal influenza vaccination for patients with systemic sclerosis to minimize the occurrence of viral infections in this high-risk population. “[Systemic sclerosis] patients regardless of disease subtype, disease severity or the use of [immunosuppressive] therapy achieved all three current immunologic standards established for seasonal vaccines/pandemic influenza vaccines to be licensed in healthy adults 18 to 60 years of age: [seroprotection rate] >70%, [seroconversion rate] >40% and FI-GMT >2.5,” concluded the researchers.

Reference

Sampaio-Barros PD, Andrade DCO, Seguro LCP, et al. Pandemic non-adjuvanted influenza A H1N1 vaccine in a cohort of patients with systemic sclerosis [published online September 8, 2017]. Rheumatology. doi: 10.1093/rheumatology/kex330