RESUMO
BACKGROUND: To examine rates of serious pneumococcal infections up to 10 years after vaccination with 7-valent conjugated pneumococcal vaccine (PCV7) in patients with arthritis compared to non-vaccinated arthritis patients. METHODS: In total, 595 adult arthritis patients (rheumatoid arthritis; RA = 342, 80 % women and spondylarthropathy; SpA = 253, 45 % women) received one dose of PCV7. Mean age/disease duration were 62/16 and 51/14 years, respectively. For each patient, 4 matched reference subjects were identified. At vaccination, 420 patients received bDMARDs (anti-TNF = 330, tocilizumab = 15, abatacept = 18, anakinra = 1, rituximab = 56). Methotrexate was given as monotherapy (n = 86) or in combination with bDMARD (n = 220). 89 SpA patients received NSAIDs without DMARD. The Skåne Healthcare Register was searched for ICD-10 diagnostic codes for pneumococcal infections (pneumonia, lower respiratory tract infection, septicemia, meningitis, septic arthritis) between January 2000 and December 2018. Frequency of infections after vs before vaccination were calculated (relative risks). Relative risk ratio (RRR) and relative risk reduction (1-RRR) were calculated comparing patients vs non-vaccinated references. Kaplan-Meier and Cox regression were used to investigate time to first event and predictors of infections. RESULTS: Among vaccinated RA and SpA patients, there was a significant relative risk reduction of pneumonia and all serious infections; 53% and 46%, respectively. There was no significant difference in time to first pneumonia or all serious infections after vaccination between patients and references. Higher age, RA diagnosis and concomitant prednisolone were associated with infections. CONCLUSION: One dose of pneumococcal conjugate vaccine may decrease risk of serious pneumococcal infection up to 10 years in patients with arthritis receiving immunomodulating treatment.