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Patients with rheumatoid arthritis receive less protection from pandemic influenza with H1N1 vaccine, study shows

Date:
May 28, 2011
Source:
European League Against Rheumatism
Summary:
Individuals with rheumatoid arthritis taking disease modifying anti-rheumatic drugs, showed significantly less protection from pandemic influenza after receiving the H1N1 vaccine compared to healthy individuals, according to new data.
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Individuals with rheumatoid arthritis taking disease modifying anti-rheumatic drugs, showed significantly less protection from pandemic influenza after receiving the H1N1 vaccine compared to healthy individuals, according to data presented at the EULAR 2011 Annual Congress.

A Brazilian hospital-based study assessed responses to flu vaccines in 340 RA patients in regular follow-up compared to 234 healthy patients. Measures of protection obtained by vaccination (seroprotection rate (SP)) after immunization was over 20% lower for RA patients compared to healthy individuals (60.1% vs. 82.9% comparatively (p<0.001)). Tests to determine levels of detectable antibodies to microorganisms in the blood serum as a result of infection and immunization with the flu virus (seroconversion rate (SC)) showed a similar pattern with 53.4% of RA patients and 76.9% of healthy controls having antibodies present respectively (p<0.001).

"This study has highlighted that there are differences in the level of protection between the H1N1 vaccine and the seasonal influenza vaccine so healthcare professionals should not assume that immune response will be the same with different vaccines" said Professor A. Ribeiro of the University of Sao Paolo. "In planning for future pandemic outbreaks, healthcare professionals should consider specific immunization strategies to ensure this large population of patients are as fully protected as possible from the risk of contracting pandemic flu."

The vaccination's impact on disease activity (DAS28*) was also measured and nine patients (2.6%) reported worsening of symptoms with the mean disease activity score changing from 3.66 to 5.15 (p<0.05) after the H1N1 vaccination. No serious adverse events were seen across either patient group, although more subjects in the RA patient group reported more adverse events, 42% versus 30.8% with a rate of 140 events/100 patients versus 87/100 control group (p<0.005).

* DAS28 (Disease Activity Score) is an index used by physicians to measure how active an individual's RA is. It assesses number of tender and swollen joints (out of a total of 28), the ethroycyte sedimentation rate (ESR, a blood marker of inflammation), and the patient's 'global assessment of global health'. A higher score indicates more active disease.


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The above post is reprinted from materials provided by European League Against Rheumatism. Note: Materials may be edited for content and length.


Cite This Page:

European League Against Rheumatism. "Patients with rheumatoid arthritis receive less protection from pandemic influenza with H1N1 vaccine, study shows." ScienceDaily. ScienceDaily, 28 May 2011. <www.sciencedaily.com/releases/2011/05/110526064635.htm>.
European League Against Rheumatism. (2011, May 28). Patients with rheumatoid arthritis receive less protection from pandemic influenza with H1N1 vaccine, study shows. ScienceDaily. Retrieved July 5, 2015 from www.sciencedaily.com/releases/2011/05/110526064635.htm
European League Against Rheumatism. "Patients with rheumatoid arthritis receive less protection from pandemic influenza with H1N1 vaccine, study shows." ScienceDaily. www.sciencedaily.com/releases/2011/05/110526064635.htm (accessed July 5, 2015).

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