High-dose flu vaccine improves immune response in RA
CHICAGO — The use of a high-dose trivalent inactivated influenza vaccine significantly improved immune response among patients with rheumatoid arthritis, compared with the standard-dose quadrivalent inactivated vaccine, according to data presented at the ACR/ARHP 2018 Annual Meeting.
“People living with rheumatoid arthritis have an increased risk for influenza infection and influenza-related illness,” Ines Colmegna, MD, of McGill University, told attendees. “This derives from inheriting new dysfunctions associated with rheumatoid arthritis, comorbidities, the age of our patients and immunosuppressive therapy. This is the basis for the current recommendations for administering influenza vaccines on an annual basis. However, people with rheumatoid arthritis have suboptimal vaccine effectiveness as a result of impaired immunogenicity. As a consequence of that, our patients have an increased risk for severe influenza, and there is a high priority to develop new approaches to decrease this risk.”
To analyze the antibody responses to both high-dose influenza vaccines and standard-dose influenza vaccines among patients with RA, Colmegna and colleagues conducted a treatment-stratified, randomized, modified, double-blind, active-controlled study of 279 participants with the disease. All patients were recruited from a tertiary care center during the 2016 to 2017 and 2017 to 2018 influenza seasons in the Northern Hemisphere. Participants were stratified by treatment they received for 3 months prior to enrollment, with 138 patients in the disease-modifying antirheumatic drug treatment group, 92 in the anti-cytokine treatment group and 49 in the anti-B cell therapy and small molecules treatment group.
A total of 140 participants received the standard vaccine, while 139 received the high-dose vaccine. The researchers analyzed seroconversion and seroprotection rates using pre- and post-vaccine serum hemagglutination inhibition titers. Seroconversion was defined as at least a fourfold hemagglutination inhibition antibody increase from prior to vaccination. The researchers defined seroprotection rate as the percent with hemagglutination inhibition titers of at least 1:40 following vaccination.
Vaccines strains used included influenza A (H3N2), influenza B, and influenza A (H1N1).
According to Colmegna, seroprotection rates pre-vaccine were comparable between both high- and standard-dose immunization groups. However, overall responses to immunization were consistently higher among those who received the high-dose vaccination. Seroconversion rates were 22.3% for the high-dose vaccine compared with 8.6% for the standard dose for H3N2; 44.6% in the high-dose group compared with 28.6% in the standard-dose group for influenza B; and 51.1% for the high dose and 30% for the standard dose for H1N1. Seroprotection rates for H3N2 were 48.5% in the high-dose group and 30.9% for the standard-dose cohort; 60.9% in the high-dose group and 50.7% in the standard group for influenza B; and 80.4% in the high-dose group and 73.5% in the standard group for H1N1.
After completing logistic regression models including age, vaccine type, treatment prior to vaccination, Charlson comorbidity index and RA duration, vaccine dose and age were the only predictors of the influenza vaccine response. Participants who received the high-dose vaccine were 2.8 times more likely to H3N2 seroconvert (OR = 2.84; 95% CI, 1.38-5.87), 2 times more likely to influenza B seroconvert (OR = 1.91; 95% CI, 1.15-3.17) and 2.3 times more likely to H1N1 seroconvert (OR = 2.33; 95% CI, 1.42-3.85).
“This is the first randomized controlled trial documenting a successful intervention to improve influenza vaccine responses in patients with rheumatoid arthritis,” Colmegna said. “This study shows that, compared to a standard dose vaccine, a high-dose vaccine improves immuno-responses to influenza vaccine strains, and is not associated with increased disease activity. Because of these conclusions, we believe that these results will likely change the clinical practice.” – by Jason Laday
Disclosure: Colmegna reports no relevant financial disclosures. Please see the full study for additional authors’ disclosures.
Colmegna I. Abstract 837. Presented at ACR/ARHP Annual Meeting, Oct. 20-24, 2018; Chicago.