Tetanus and diphtheria immunity in refugees in Europe in 2015.

BACKGROUND: Current political crises in the Middle East and economic discrepancies led millions of people to leave their home countries and to flee to Western Europe. This development raises unexpected challenges for receiving health care systems. Although pan-European initiatives strive for updated and optimized vaccination strategies, little data on immunity against vaccine-preventable diseases in the current refugee population exist.

METHODS: We quantified serum IgG against tetanus and diphtheria (TD) in n = 678 refugees currently seeking shelter in six German refugee centers.

FINDINGS: Reflecting current migration statistics in Europe, the median age within the cohort was 26 years, with only 23.9 % of female subjects. Insufficient IgG levels without long-term protection against tetanus were found in 56.3 % of all refugees. 76.1 % of refugees had no long-term protection against diphtheria. 47.7 % of subjects needed immediate vaccination against tetanus, and 47.7 % against diphtheria. For both diseases, an age-dependent decline in protective immunity occurred.

INTERPRETATION: We observed a considerably low rate of tetanus-protected refugees, and the frequency of diphtheria-immune refugees was far from sufficient to provide herd immunity. These findings strongly support recent intentions to implement and enforce stringent guidelines for refugee vaccination in the current crisis.