Immunogenicity and Safety of Vaccinations in Immunocompromised Persons

Backgound and relevance of the project:

Patients with autoimmune inflammatory rheumatic diseases (AIIRD) are at increased risk of contracting infections. The increased risk can be attributed to the immunological disorder itself, as well as to the immunosuppressive treatment. Vaccination against many infections is recommended in this patient group. However, the immunogenicity of vaccines may be reduced and may also be influenced by the administered treatment. Potential reactivation of the underlying disease triggered by vaccination is another important concern.

From the patients' and public health perspectives, an important task of physicians is giving advice on vaccines. Completing this task is often difficult, because data on the immunogenicity and safety of vaccines in these patient groups are scarce, especially with regard to treatment with new immunosuppressive medications, such as biological agents. Lastly and importantly, due to new therapeutic options, health among AIIRD patients has considerably improved and an increasing number of patients undertake overseas travel activities requiring additional vaccinations. In this context, reliable advice with regard to vaccinations is almost impossible, because for most travel vaccinations the immunogenicity and safety profile is unknown.

Research addressing the immunogenicity and safety of vaccines in different autoimmune inflammatory diseases treated with different immunosuppressive medications is urgently needed to allow giving evidence based vaccine advice.

In this observational study the immunogenicity and safety of tetanus booster and hepatitis A vaccinations will be assessed in AIIRD patients. The immune response will be evaluated as a function of the underlying disease and the possible influence of commonly used immunosuppressive drugs on the immune response will be studied.

Rationale for studying tetanus booster and hepatitis A vaccine Tetanus vaccination is one of the most frequently recommended vaccinations, and the effect of a booster vaccination can be addressed. Hepatitis A vaccine is the most widely used travel vaccine. Despite their importance, only very limited data are available for tetanus and hepatitis A vaccine in this patient group. By focusing on these vaccines the study will lead the way to the evaluation of further vaccines.

The purpose of this study is to determine whether tetanus and hepatitis A vaccinations are as immunogenic and safe in AIIRD patients as in healthy controls.