How well are patients with inflammatory rheumatic diseases protected against measles?

Patients with inflammatory rheumatic diseases have an increased risk of infections due to the autoimmune disease but also due to the immunosuppressive medication. Although vaccinations are known to be effective in the primary prophylaxis of infections, the vaccination rate in Germany is generally too low. Due to the recently increasing, sometimes epidemic-like occurrence of measles, the administration of live vaccine against measles has recently become required by law. How many patients with inflammatory rheumatic diseases are currently sufficiently protected against measles? Between December 2017 and October 2018 patients with inflammatory rheumatic diseases at the Ruhrgebiet Rheumatism Center were prospectively and consecutively included. Data on the disease and treatment at the level of substance classes, patient history of vaccination and infections were collated. All information on vaccinations were controlled in the vaccination certificate. Antibodies against measles were determined using ELISA. The threshold for sufficient protection against measles was set at 150 mIU/ml. Out of 975 patients 540 (55.4%) could present a vaccination certificate. In 201 patients with a certificate (37.2%) vaccination had been documented since birth. Overall, 45 out of 267 patients born after 1970 (16.9%) had sufficient protection against measles. The patient history of measles in childhood showed no differences between patients with and without protective measles IgG antibodies. Protective measles IgG antibodies were detected in 901 out of 928 patients with measurement of the measles IgG antibody level (97.1%). The different principles of action of the current immunosuppressive treatments had no influence on this. These data show that at least 2.9% of the patients did not have sufficient protection against measles. Interestingly, the majority of patients born after 1970 had protective antibodies despite the lack of vaccination against measles. The efforts in primary and also in the specialist medical care should be urgently strengthened in order to be able to guarantee an adequate infection prophylaxis in particularly endangered patients.