H1N1 vaccine is safe for individuals with autoimmune diseases

A study conducted by researchers at Universidade de São Paulo’s (USP) Medical School proved the immunogenicity and safety of the H1N1 vaccine against patients with rheumatic autoimmune diseases and in people subjected to immunosuppressive therapy, including individuals with cancer or receiving transplants.

By Elton Alisson

Agência FAPESP – People living with autoimmune diseases, including lupus and rheumatoid arthritis, have a higher risk of infection than the general population. For this reason, receiving vaccinations against such new viruses, as H1N1, which causes the flu, is essential. However, until now, it was unclear whether the vaccines developed to combat this type of flu virus presented risks or would be effective for these patients.

A study conducted by researchers at Universidade de São Paulo’s (USP) Medical School proved the immunogenicity and safety of the H1N1 vaccine against patients with rheumatic autoimmune diseases and in people subjected to immunosuppressive therapy, including individuals with cancer or receiving transplants.

The results of the study, which received FAPESP funding and was coordinated by Professor Eloisa Silva Dutra de Oliveira Bonfá, were presented at the Annual Scientific Meeting of the American College of Rheumatology (ACR), held in Chicago from November 4 to 9, 2011, and published previously in the Annals of the Rheumatic Diseases.

During the study, 1,668 patients diagnosed with conditions that included rheumatoid arthritis, spondylarthritis, systemic lupus erythematosus, dermatomyosite, mixed connective tissue disease, systemic vasculitis, systemic sclerosis, Sjögren syndrome, antiphospholipid syndrome and juvenile idiopathic arthritis, among others, were evaluated and vaccinated against H1N1 at Hospital das Clínicas and the Pediatric Rheumatology Unit at USP’s Children’s Institute.

Another 234 healthy individuals were recruited to receive a vaccine developed by the Butantan Institute in partnership with the pharmaceutical company, Sanofi-Aventis.

Both the patients with rheumatic autoimmune diseases and the control group were monitored for 21 days following the vaccination for side effects.

In comparing the immune reactions of the two groups to the vaccine, the researchers found that, in general, the responses of the patients with rheumatic diseases were the same as the healthy individuals.

“The immune response to the vaccine against H1N1 in the normal population was around 77%, against 63% of patients with autoimmune diseases. Based on this, we can now securely affirm that these patients can be vaccinated against the flu because they react to the vaccine,” said Bonfá to Agência FAPESP.

According to Bonfá, the immune response to the vaccine against H1N1 in those patients diagnosed with lupus, rheumatoid arthritis and psoriatic arthritis, was lower than that presented by healthy people.

An investigation by the researchers found that the causes for this difference was due to the effect of the immunosuppressants and corticoids utilized in the treatment of these patients. Furthermore, when these medications were associated with the use of chloroquine – an antimalarial drug commonly used in the treatment of rheumatic autoimmune diseases – the immune response of these patients to the vaccine tended to normalize.

The discovery will be published in the next editions of the journal Rheumatology, which is published by the British Society of Rheumatology. “Now we intend to conduct a cellular study with antimalarials to evaluate immune response,” said Bonfá.

Adjuvants

In another study, the Brazilian researchers identified corticoid as the most important factor for diminishing the immunogenicity of the H1N1 vaccine against H1N1 in children with rheumatic autoimmune diseases. The results of the study will be published in The Journal of Rheumatology.

“The discoveries of these studies are very important and have a very large impact on the day to day life of health professionals who care for patients with autoimmune diseases because now, they can feel secure about using the vaccine,” evaluates Bonfá.

According to the researcher, no serious side effects from the vaccine requiring hospitalization were observed in the patients with rheumatic autoimmune diseases.

Researchers attributed this results to the utilization of vaccines without the immunological adjuvants (compounds that stimulate the autoimmune response) that are normally used in vaccination campaigns in Brazil.

“As these patients already have altered autoimmune response, any protein given to them could worsen the disease. In this manner, the vaccine without immunological adjuvants offers an advantage to them,” says Bonfá.

The articles, Reduced seroprotection after pandemic H1N1 influenza adjuvant-free vaccination in patients with rheumatoid arthritis: implications for clinical practice (doi:10.1136/ard.2011.152983) and Immunogenicity and safety of the 2009 non-adjuvanted influenza A/H1N1 vaccine in a large cohort of autoimmune rheumatic diseases (doi:10.1136/ard.2011.150250), can be read by subscribers to Annals of the Rheumatic Diseases at http://ard.bmj.com.