High-dose influenza vaccination substantially improves immune responses against influenza in adults with seropositive rheumatoid arthritis, according to new research findings presented this week at the 2018 ACR/ARHP Annual Meeting (Abstract #837).

3D print of influenza virus. The virus surface (yellow) is covered with proteins called hemagglutinin (blue) and neuraminidase (red). NIH
3D print of influenza virus. The virus surface (yellow) is covered with proteins called hemagglutinin (blue) and neuraminidase (red). NIH

Rheumatoid arthritis (RA) is the most common type of autoimmune arthritis. It is a chronic disease that causes joint pain, stiffness, swelling and decreased movement of the joints. Small joints in the hands and feet are most commonly affected. Sometimes RA can affect your organs, such as eyes, skin or lungs. About 75 percent of RA patients are women.

RA patients have a 2.75-fold increased risk of influenza than healthy patients in the same age group, so annual flu vaccination is a high priority for them. While vaccination is an effective intervention, vaccine-induced antibody responses and flu protection in people with RA are suboptimal. A group of researchers in Montreal, Canada, conducted a study to find out if a high-dose vaccine could enhance the production of antibodies against influenza in people with RA by comparing a high-dose trivalent inactivated influenza vaccine (HD-TIV) to a standard-dose quadrivalent inactivated influenza vaccine (SD-QIV).

“The burden of influenza among people with RA is disproportionally high, and interventions to improve responses to influenza vaccination are urgently needed,” said Ines Colmegna, MD, Associate Professor, Division of Rheumatology, McGill University, and the study’s presenting author. “Strategies to optimize protection in the elderly, another vulnerable group, include the use of quadrivalent vaccines, higher antigen doses and adjuvants. In adults 65 years of age or older, the HD-TIV improved immunogenicity and protection. Like the elderly, RA patients have reduced vaccine-induced protection that limits the impact of vaccination in reducing morbidity and mortality associated with influenza.”

Their study aimed to explore whether strategies used in the elderly would also enhance protection in adults with RA. Using a treatment-stratified, randomized, modified double-blind, active-controlled trial, the researchers assessed the antibody responses to either SD-QIV (15 μg of hemagglutinin (HA) per strain) or HD-TIV (60 μg of HA per strain) in a total of 279 adult seropositive RA patients. Of this group, 140 received SD-QIV and 139 received HD-TIV. The patients were recruited from a tertiary care center during the 2016-2017 and 2017-2018 flu seasons. The mean age of the patients in the study was 61, and 80 percent were female.

Vaccination responses were relatively low in the RA patients. However, responses were consistently higher in the HD-TIV group. In logistic regression models, only vaccine dose and patient age were predictors of vaccine seroresponse. The data showed that patients that received HD-TIV were 2.8 times more likely to H3N2 seroconvert, two times more likely to B/Brisbane seroconvert and 2.3 times more likely to H1N1 seroconvert.

The study found HD-TIV substantially improves the immune response to flu vaccination for seropositive RA patients compared to a standard dose.

“Influenza vaccines are safe, effective and associated with significant reductions in the number of physician visits, hospitalizations for pneumonia or influenza, and deaths among high-risk adults,” said Dr. Colmegna. “The McGill study shows that HD-TIV provides better seroprotection against influenza in RA patients. These results together with the fact that the HD-TIV was as safe as the SD-TIV may lead to changes in practice (i.e. recommendation to use HD instead of SD influenza vaccine in RA) and inform public health decisions.”