title: Common vaccinations among adults do not increase the risk of developing rheumatoid arthritis: results from the Swedish EIRA study.
abstract: OBJECTIVE
  To investigate the association between vaccinations in adults and the risk of developing rheumatoid arthritis (RA).
  
  
  METHODS
  Data from the Swedish population-based Epidemiological Investigation of RA case-control study encompassing 1998 incident cases of RA aged 18-70 years and 2252 randomly selected controls matched for age, sex and residency were analysed. Those vaccinated within 5 years before disease onset were compared with those not vaccinated by calculating OR with 95% CI.
  
  
  RESULTS
  Vaccinations neither increased the risk of RA overall (OR 1.0, 95% CI 0.9 to 1.1) nor the risk of two major subgroups of RA (antibodies to citrullinated peptide-positive (ACPA-positive) and ACPA-negative disease). Furthermore, vaccinations did not increase the risk of RA in smokers or carriers of HLA-DRB1 shared epitope alleles, two groups with established risk factors for RA.
  
  
  CONCLUSIONS
  In this case-control study of incident cases of newly diagnosed RA, no increased risk of RA following immunisation was observed for vaccinations overall or for any specific vaccination. This indicates that immunological provocation of adults with commonly used vaccines in their present form carries no risk of RA. These findings should be implemented among public healthcare providers in order to encourage vaccinations according to recommended national vaccination schedules.
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Box 210, S-171 77 Stockholm, Sweden. camilla.bengtsson@ki.se
authors.forename: Camilla
authors.initials: C
authors.lastname: Bengtsson
authors.forename: Meliha C
authors.initials: MC
authors.lastname: Kapetanovic
authors.forename: Henrik
authors.initials: H
authors.lastname: Källberg
authors.forename: Berit
authors.initials: B
authors.lastname: Sverdrup
authors.forename: Birgitta
authors.initials: B
authors.lastname: Nordmark
authors.forename: Lars
authors.initials: L
authors.lastname: Klareskog
authors.forename: Lars
authors.initials: L
authors.lastname: Alfredsson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics / Q000276:immunology; D001323:Autoantibodies / Q000097:blood; D016022:Case-Control Studies; D005838:Genotype; D006684:HLA-DR Antigens / Q000235:genetics; D059811:HLA-DRB1 Chains; D006801:Humans; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D013548:Sweden / Q000453:epidemiology; D014611:Vaccination / Q000009:adverse effects* / Q000706:statistics & numerical data; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide