RA drugs have limited effect on pneumococcal vaccination efficacy
medwireNews: Researchers report that some antirheumatic drugs may limit the humoral response of patients with rheumatoid arthritis (RA) to pneumococcal vaccination, but they nonetheless stress that this should not preclude immunization against such preventable diseases.
Patients with RA are at increased risk for infection compared with healthy individuals due to a complex interaction of inherent immune dysfunction, comorbidity, disease activity, and immunosuppression, say Sujith Subesinghe (King’s College London, UK) and co-workers.
Despite finding some evidence of a diminished humoral response to pneumococcal immunization in RA patients taking methotrexate, they maintain that “[v]accination is safe, well-tolerated and should be encouraged as part of routine clinical care” for such patients.
The findings come from a meta-analysis of nine studies investigating the impact of antirheumatic drugs on vaccination responses in RA patients – seven involving immunization against influenza and two against pneumococcal infections.
The studies included pandemic and seasonal trivalent subunit influenza vaccines, 23-valent pneumococcal polysaccharide vaccine, and 7- and 13-valent pneumococcal conjugated vaccines.
Five of the studies looked at the effect of methotrexate on influenza vaccination responses in 350 RA patients and 437 healthy controls and seven studies investigated the effect of tumor necrosis factor (TNF) inhibitor treatment in 263 RA patients and 499 healthy controls.
For pneumococcal vaccination response, two studies of 254 individuals (122 with RA and 132 healthy controls) examined methotrexate exposure and two involving 273 individuals (141 with RA and 132 healthy controls) examined TNF inhibitor exposure.
Vaccine immunogenicity was assessed by seroprotection rates at 3 to 6 weeks after immunization.
Subesinghe et al report that influenza vaccine responses to all subunit strains assessed – the H1N1, H3N2, and B strains – were maintained in patients exposed to methotrexate or TNF inhibitors.
Methotrexate was, however, associated with reduced response to vaccination against bacterial pneumonia associated with 6B and 23F serotypes, at a pooled relative risk of 0.42 compared with healthy controls. The researchers acknowledge that the data from the two studies were limited.
In addition, the combination of methotrexate with tocilizumab or tofacitinib was associated with reduced pneumococcal and influenza vaccine responses, whereas there was no impact on pneumococcal vaccination response with TNF inhibitor treatment.
The researchers comment on the challenging nature of measuring pneumococcal vaccination response because of the significant heterogeneity in the reporting of responses, and acknowledge that while they only considered responses to the less prevalent 6B and 23F serotypes, infections associated with these serotypes carry a high risk for mortality.
They also point out that achieving a satisfactory response to one serotype does not necessarily equate to other serotypes.
The researchers nevertheless conclude by stressing the importance of vaccination. “Increasing the awareness and uptake of vaccinations in patients with RA will require collaborative approaches between primary and secondary care,” they write in The Journal of Rheumatology.
By Anita Chakraverty
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