Immunogenicity and Safety of Influenza A/H3N2 Vaccine in Patients With Rheumatologic Diseases

Studies in the literature have shown reduced effectiveness of influenza A (H3N2) virus vaccine (20-40%) when compared to A (H1N1) and influenza B. This reduction in efficacy may partly result of the need to propagate A (H3N2) virus into egg components for the preparation of the vaccine. Other factors that may also contribute to the reduction of efficacy against A (H3N2) viruses include the high level of genetic diversity and the rate of rapid evolution of this particular virus subtype and the modification of the immune response to the vaccine secondary of prior infection or vaccination.

Vaccine efficacy studies are required to verify the immunogenicity of the H3N2 influenza vaccine in immunosuppressed patients with rheumatologic disease. In addition, it is relevant to evaluate the safety of the vaccine in this population as well as the possibility of reactivation of the rheumatologic disease itself. The objectives of this study are to:

1. Evaluate the immunogenicity of the H3N2 component of the inactivated and fragmented influenza vaccine (A / Michigan / 45/2015 (H1N1) pdm09-like virus, A / Singapore / INFIMH-16-0019 / 2016 (H3N2) -like virus; B / Phuket / 3073/2013-like virus] in patients with two systemic autoimmune rheumatic diseases (Systemic Lupus Erythematosus - Adult and Juvenile, Primary Sjögren's Syndrome).
2. Assess the safety of immunization with the inactivated influenza vaccine [A / Michigan / 45/2015 (H1N1) pdm09-like virus, A / Singapore / INFIMH-16-0019 / 2016 (H3N2) -like virus; B / Phuket / 3073/2013-like virus] in these patients with systemic autoimmune rheumatic diseases.
3. Evaluate the possible association between vaccinal immunogenicity with: demographic data, clinical and laboratorial activity of the disease, and treatment of patients with these rheumatic diseases.

Patients with diagnosis of adult and juvenile systemic lupus erythematosus (SLE and JSLE) (n=100) and Sjogren syndrome (SSp) (n=30) according to the classification criteria established for these diseases will be prospectively evaluated at the Hospital das Clínicas of the University of São Paulo (HC-FMUSP).

The control group will consist of 120 healthy individuals who will be recruited into the vaccination campaign paired for age and sex. The juvenile control group will be composed of 50 healthy children who will be recruited in the vaccination campaign paired for age and sex.